WorldWideScience

Sample records for codes water jet

  1. Study of Water Jet Impulse in Water-Jet Looms

    Institute of Scientific and Technical Information of China (English)

    LI Ke-rang; MA Wei-wei; CHEN Ming

    2005-01-01

    The water jet impulse is brought forward to study the traction force of the water jet to the flying weft in water-jet looms. The distribution of the water jet impulse in the shed is tested by a sensor, and the influence of water jet parameters on the water jet impulse is analyzed.

  2. Dynamics of Water Jet in Water Jet Looms

    Institute of Scientific and Technical Information of China (English)

    李克让; 陈明

    2001-01-01

    On the base of the study on dynamics of water jet in water jet looms, the parameters of water jet mechanism which affect the speed of water jet are analyzed and optimized. So the stability of the water jet can be improved to raise the speed of water jet as well as weft insertion rate and to enlarge the width of woven fabrics a lot. At the same time it also points out that to increase water jet speed and to prolong its affective jet time depend mainly on the accretion of spring rate (constant)of stiffness and the diminution of plunger's cross sectional area respectively.

  3. [Liver resection by water jet].

    Science.gov (United States)

    Horie, T

    1989-01-01

    Major problem in resecting liver parenchyma is how to control the bleeding. Recently, resection of the liver by water jet has been reported. So, experimental and clinical studies were performed to investigate the usefulness of the water jet equipment. Ten pigs weighing around 17kg were used. The optimal pressure to resect the porcine liver was 7 to 15kg/cm2. By 4 weeks the cut surface was covered with fibrous capsule. Portal angiography showed no abnormality in the resected area. The water jet was also used in 30 human operations. The optimal pressure was 12 to 18kg/cm2 for non cirrhotic liver and 15 to 20kg/cm2 for cirrhotic liver. The surface immediately after jet cutting was more smooth than that of CUSA and histologically there was slight bleeding and necrosis. The volume of blood loss during dissection was not different between water jet group and CUSA group. No significant changes were found in the laboratory data. These results suggest that water jet is as useful as CUSA for cutting the liver parenchyma.

  4. Enhancement of the SPARC90 code to pool scrubbing events under jet injection regime

    Energy Technology Data Exchange (ETDEWEB)

    Berna, C., E-mail: ceberes@iie.upv.es [Instituto de Ingeniería Energética, Universitat Politècnica de València (UPV), Camino de Vera 14, 46022 Valencia (Spain); Escrivá, A.; Muñoz-Cobo, J.L. [Instituto de Ingeniería Energética, Universitat Politècnica de València (UPV), Camino de Vera 14, 46022 Valencia (Spain); Herranz, L.E., E-mail: luisen.herranz@ciemat.es [Unit of Nuclear Safety Research Division of Nuclear Fission, CIEMAT, Avda. Complutense 22, 28040 Madrid (Spain)

    2016-04-15

    Highlights: • Review of the most recent literature concerning submerged jets. • Emphasize all variables and processes occurring along the jet region. • Highlight the gaps of knowledge still existing related to submerged jets. • Enhancement of SPARC90-Jet to estimate aerosol removal under jet injection regime. • Validation of the SPARC90-Jet results against pool scrubbing experimental data. - Abstract: Submerged gaseous jets may have an outstanding relevance in many industrial processes and may be of particular significance in severe nuclear accident scenarios, like in the Fukushima accident. Even though pool scrubbing has been traditionally associated with low injection velocities, there are a number of potential scenarios in which fission product trapping in aqueous ponds might also occur under jet injection regime (like SGTR meltdown sequences in PWRs and SBO ones in BWRs). The SPARC90 code was developed to determine the fission product trapping in pools during severe accidents. The code assumes that carrier gas arrives at the water ponds at low or moderate velocities and it forms a big bubble that eventually detaches from the injection pipe. However, particle laden gases may enter the water at very high velocities resulting in a submerged gas jet instead. This work presents the fundamentals, major hypotheses and changes introduced into the code in order to estimate particle removal during gas injection in pools under the jet regime (SPARC90-Jet). A simplified and reliable approach to submerged jet hydrodynamics has been implemented on the basis of updated equations for jet hydrodynamics and aerosol removal, so that gas–liquid and droplet-particles interactions are described. The code modifications have been validated as far as possible. However, no suitable hydrodynamic tests have been found in the literature, so that an indirect validation has been conducted through comparisons against data from pool scrubbing experiments. Besides, this validation

  5. REVIEW OF WATER JET APPLICATIONS IN MANUFACTURING

    OpenAIRE

    Faruk MENDİ; KÜLEKÇİ, Mustafa Kemal

    1999-01-01

    Usage of water jets in manufacturing processes, has been known for many decades. A wide range of engineering materials can be cut by water jets with satisfactory results. Enhanced reliability and efficiency of the technique, have yielded the technology greater interest for manufacturing applications. Water jets are used to cut soft materials such as wood, plastics, aluminium and copper. Abrasive water jets are used to cut very hard materials such as titanium, inconel, glass and ceramics. It i...

  6. REVIEW OF WATER JET APPLICATIONS IN MANUFACTURING

    Directory of Open Access Journals (Sweden)

    Faruk MENDİ

    1999-02-01

    Full Text Available Usage of water jets in manufacturing processes, has been known for many decades. A wide range of engineering materials can be cut by water jets with satisfactory results. Enhanced reliability and efficiency of the technique, have yielded the technology greater interest for manufacturing applications. Water jets are used to cut soft materials such as wood, plastics, aluminium and copper. Abrasive water jets are used to cut very hard materials such as titanium, inconel, glass and ceramics. It is impossible to cut these materials with classical cutting technics. A water jet processing system utilises water pressure in the range of 100Mpa-400Mpa, for the different applications. In abrasive water jet milling and abrasive water jet cutting processes, the pressure of the jet is about 400Mpa. In water jet surface penning, the jet pressure is about 100Mpa. The process of abrasives mixing with the water stream is a complex phenomena. Erosion processes involved in cutting not yet fully understood. The lack of understanding the process call for other strategies in finding appropriate ways to obtain a precision depth in cutting operation. In this paper the principles of water jet systems had been explained. Results of experiments that made on cutting process and surface strengthening with water jet had been given.

  7. Arc Jet Facility Test Condition Predictions Using the ADSI Code

    Science.gov (United States)

    Palmer, Grant; Prabhu, Dinesh; Terrazas-Salinas, Imelda

    2015-01-01

    The Aerothermal Design Space Interpolation (ADSI) tool is used to interpolate databases of previously computed computational fluid dynamic solutions for test articles in a NASA Ames arc jet facility. The arc jet databases are generated using an Navier-Stokes flow solver using previously determined best practices. The arc jet mass flow rates and arc currents used to discretize the database are chosen to span the operating conditions possible in the arc jet, and are based on previous arc jet experimental conditions where possible. The ADSI code is a database interpolation, manipulation, and examination tool that can be used to estimate the stagnation point pressure and heating rate for user-specified values of arc jet mass flow rate and arc current. The interpolation is performed in the other direction (predicting mass flow and current to achieve a desired stagnation point pressure and heating rate). ADSI is also used to generate 2-D response surfaces of stagnation point pressure and heating rate as a function of mass flow rate and arc current (or vice versa). Arc jet test data is used to assess the predictive capability of the ADSI code.

  8. Testing and Analysis of the Speed of Water Jet in Water Jet Looms

    Institute of Scientific and Technical Information of China (English)

    李克让; 麻伟巍; 陈明

    2003-01-01

    In the water jet looms, the distribution of the speed of water jet at the axis of the shed and its regularity are obtained by the Laser Doppler Tester. Based on the above, the water jet system is analyzed and the main effective approaches to increase the filling insertion rate and to widen the reed space of the loom are pointed out.

  9. Reducing Coal Dust With Water Jets

    Science.gov (United States)

    Gangal, M. D.; Lewis, E. V.

    1985-01-01

    Jets also cool and clean cutting equipment. Modular pick-and-bucket miner suffers from disadvantage: Creates large quantities of potentially explosive coal dust. Dust clogs drive chain and other parts and must be removed by hand. Picks and bucket lips become overheated by friction and be resharpened or replaced frequently. Addition of oscillating and rotating water jets to pick-and-bucket machine keeps down dust, cools cutting edges, and flushes machine. Rotating jets wash dust away from drive chain. Oscillating jets cool cutting surfaces. Both types of jet wet airborne coal dust; it precipitates.

  10. Biofilm removal with a dental water jet.

    Science.gov (United States)

    Gorur, Amita; Lyle, Deborah M; Schaudinn, Christoph; Costerton, John W

    2009-03-01

    The objective of this study was to evaluate the effect of a dental water jet on plaque biofilm removal using scanning electron microscopy (SEM). Eight teeth with advanced aggressive periodontal disease were extracted. Ten thin slices were cut from four teeth. Two slices were used as the control. Eight were inoculated with saliva and incubated for 4 days. Four slices were treated using a standard jet tip, and four slices were treated using an orthodontic jet tip. The remaining four teeth were treated with the orthodontic jet tip but were not inoculated with saliva to grow new plaque biofilm. All experimental teeth were treated using a dental water jet for 3 seconds on medium pressure. The standard jet tip removed 99.99% of the salivary (ex vivo) biofilm, and the orthodontic jet tip removed 99.84% of the salivary biofilm. Observation of the remaining four teeth by the naked eye indicated that the orthodontic jet tip removed significant amounts of calcified (in vivo) plaque biofilm. This was confirmed by SEM evaluations. The Waterpik dental water jet (Water Pik, Inc, Fort Collins, CO) can remove both ex vivo and in vivo plaque biofilm significantly.

  11. All-Water-Jet Coal Excavator

    Science.gov (United States)

    Gangal, M. D.

    1985-01-01

    Version of jaw miner operates without mechanical cutting and crushing. Forward-pointing jets of water dislodge and break up coal. Rearward-pointing jets further break up coal and force particles into slurry chamber. Oscillatingjet mechanism itself stays within "jaw" structure and protected from wear and tear associated with coal handling. All-jet machine generates even less dust than anger, therefore poses lesser explosion or health hazard.

  12. Impeller for Water Jet Propulsion

    Science.gov (United States)

    2004-01-01

    Marshall Space Flight Center engineers helped North American Marine Jet (NAMJ), Inc. improve the proposed design of a new impeller for jet propulsion system. With a three-dimensional computer model of the new marine jet engine blades, engineers were able to quickly create a solid ploycarbonate model of it. The rapid prototyping allowed the company to avoid many time-consuming and costly steps in creating the impeller.

  13. Hepatic Resection Using a Water Jet Dissector

    Science.gov (United States)

    Stain, S. C.; Guastella, T.; Maddern, G. J.; Blumgart, L. H.

    1993-01-01

    The mortality and morbidity in major hepatic resection is often related to hemorrhage. A high pressure, high velocity water jet has been developed and has been utilized to assist in hepatic parenchymal transection. Sixty-seven major hepatic resections were performed for solid hepatic tumors. The tissue fracture technique was used in 51 patients (76%), and the water jet dissector was used predominantly in 16 patients (24%). The extent of hepatic resection using each technique was similar. The results showed no difference in operative duration (p = .499). The mean estimated blood loss using the water jet was 1386 ml, and tissue fracture technique 2450 ml (p = .217). Transfusion requirements were less in the water jet group (mean 2.0 units) compared to the tissue fracture group (mean 5.2 units); (p = .023). Results obtained with the new water dissector are encouraging. The preliminary results suggest that blood loss may be diminished. PMID:8387808

  14. Reliability of astrophysical jet simulations in 2D: On inter-code reliability and numerical convergence

    OpenAIRE

    Krause, M.; M. Camenzind

    2001-01-01

    In the present paper, we examine the convergence behavior and inter-code reliability of astrophysical jet simulations in axial symmetry. We consider both, pure hydrodynamic jets and jets with a dynamically significant magnetic field. The setups were chosen to match the setups of two other publications, and recomputed with the MHD code NIRVANA. We show that NIRVANA and the two other codes give comparable, but not identical results. We find that some global properties of a hydrodynamical jet si...

  15. Evaluation of water-jet-assisted cutting

    National Research Council Canada - National Science Library

    1987-01-01

    Recent studies show that the addition of a water jet to the cutting bit can improve cutting performance in harder materials, significantly reduce respirable dust and bit wear, and increase particle size...

  16. Water jet and abrasive water jet cutting of unidirectional graphite/epoxy composite

    Science.gov (United States)

    Ramulu, M.; Arola, D.

    1993-06-01

    Unidirectional graphite/epoxy composite material has been machined by water jet and abrasive water jet cutting processes. Topography and morphology of the machined surfaces were evaluated with surface profilometry and scanning electron microscopy. The surface characteristics in terms of roughness and the micromechanisms of material removal for both processes were analyzed and compared. Abrasive water jet surface characteristics of graphite/epoxy were found to be significantly different from those of the water jet cutting process and micromechanical behavior of material removal was strongly dependent on the fiber orientation.

  17. Liver resection using a water jet.

    Science.gov (United States)

    Une, Y; Uchino, J; Horie, T; Sato, Y; Ogasawara, K; Kakita, A; Sano, F

    1989-01-01

    The water-jet method has been used during hepatic resection. The instrument cuts the hepatic tissue with the high pressure of the fine water flow, while the exposed elastic intrahepatic vessels are spared injury. A comparative study on the water-jet method with the previously employed conventional methods was undertaken. Hepatic resections were performed on 35 patients using the water-jet method. Cirrhosis of the liver was associated with 10 of the 24 patients with hepatocellular carcinoma. An ordinary saline solution was used as the jet, which was projected at a pressure of between 12 kg/cm2 and 20 kg/cm2 through a 0.15/mm-diameter nozzle. A higher jet pressure was needed to cut the fibrotic hepatic parenchyma. In the case of normal liver, the intrahepatic vessels of more than 0.2 mm were well preserved. In most of the cases, the loss of blood when cutting the hepatic parenchyma can be easily reduced with a jet pressure of 15-16 kg/cm2, thus preserving the fine vessels more than 0.2 mm in diameter without injury. When the same pressure was applied in the cutting of a cirrhotic liver, it took much longer time compared to that of a non-cirrhotic normal liver parenchyma. The cut surface was smooth compared to that after using CUSA, although its disadvantages lie in the formation of air bubbles, which obscure the operative field. The controlled projection of a jet of water under optimal pressure may ensure a safe hepatic resection of both normal and cirrhotic livers. Furthermore, because of its uncomplicated form, a wide range of applications can be expected, while the lower cost will also expedite its large-scale use for economic reasons.

  18. Circular and Elliptic Submerged Impinging Water Jets

    Science.gov (United States)

    Claudey, Eric; Benedicto, Olivier; Ravier, Emmanuel; Gutmark, Ephraim

    1999-11-01

    Experiments and CFD have been performed to study circular and elliptic jets in a submerged water jet facility. The tests included discharge coefficient measurement to evaluate pressure losses encountered in noncircular nozzles compared to circular ones. Three-dimensional pressure mappings on the impingement surface and PIV measurement of the jet mean and turbulent velocity have been performed at different compound impingement angles relative to the impingement surface and at different stand-off distances. The objective was to investigate the effect of the non-circular geometry on the flow field and on the impact region. The tests were performed in a close loop system in which the water was pumped through the nozzles into a clear Plexiglas tank. The Reynolds numbers were typically in the range of 250000. Discharge coefficients of the elliptic nozzle was somewhat lower than that of the circular jet but spreading rate and turbulence level were higher. Pressure mapping showed that the nozzle exit geometry had an effect on the pressure distribution in the impact region and that high-pressure zones were generated at specific impact points. PIV measurements showed that for a same total exit area, the elliptic jets affected a surface area that is 8the equivalent circular. The turbulence level in the elliptic jet tripled due to the nozzle design. Results of the CFD model were in good agreement with the experimental data.

  19. Numerical simulation of high pressure water jet impacting concrete

    Science.gov (United States)

    Liu, Jialiang; Wang, Mengjin; Zhang, Di

    2017-08-01

    High pressure water jet technology is an unconventional concrete crushing technology. In order to reveal the mechanism of high pressure water jet impacting concrete, it built a three-dimensional numerical model of high pressure water jet impacting concrete based on fluid mechanics and damage mechanics. And the numerical model was verified by theoretical analysis and experiments. Based on this model, it studied the stress characteristics in concrete under high pressure water jet impacting at different time, and quantified the damage evolution rules in concrete along the water jet radial direction. The results can provide theoretical basis and guidance for the high pressure water jet crushing concrete technology.

  20. [Temperature measurements during abrasive water jet osteotomy].

    Science.gov (United States)

    Schmolke, S; Pude, F; Kirsch, L; Honl, M; Schwieger, K; Krömer, S

    2004-01-01

    Working on bone is a major aspect of orthopaedic surgery. Despite its well-known appreciable thermal effects on the edges of the bone cut, the oscillating bone saw blade the oscillating saw remains the standard instrument both for cutting long bones and creating a bed for an endoprosthesis. The application of abrasive water jets offers the possibility of achieving an extremely precise curved cut in bone with no accompanying thermal effect. The thermographically measured absolute temperature increase at the cut edges seen with the water jet was 13 K maximum. The small process forces permit the application in automated handling systems.

  1. Description of premixing with the MC3D code including molten jet behavior modeling. Comparison with FARO experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Berthoud, G.; Crecy, F. de; Meignen, R.; Valette, M. [CEA-G, DRN/DTP/SMTH, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France)

    1998-01-01

    The premixing phase of a molten fuel-coolant interaction is studied by the way of mechanistic multidimensional calculation. Beside water and steam, corium droplet flow and continuous corium jet flow are calculated independent. The 4-field MC3D code and a detailed hot jet fragmentation model are presented. MC3D calculations are compared to the FARO L14 experiment results and are found to give satisfactory results; heat transfer and jet fragmentation models are still to be improved to predict better final debris size values. (author)

  2. Pool scrubbing under jet injection regime: An enhancement of the SPARC90 code

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L. E. [Unit of Nuclear Safety Research, Div. of Nuclear Fission, CIEMAT, Avda.Complutense 40, 28040 Madrid (Spain); Berna, C.; Escriva, A.; Munoz-Cobo, J. L. [Instituto de Ingenieria Energetica, Universidad Politecnica de Valencia UPV, Camino de Vera 14, 46022 Valencia (Spain)

    2012-07-01

    The SPARC90 code was developed to calculate the aerosol pool trapping during vent discharge processes, at low gas velocities. However, there are accident sequences, like SGTR core meltdown sequences, at which particle laden gases reach the aqueous ponds at very high velocities and new particle removal mechanisms become effective right at the inlet. As a result of the shearing off of roll wave water crests, water droplets are entrained in the gas core and sweep out aerosol particles, mainly by inertial impaction and interception. This paper summarizes the update of the SPARC90 code based on state-of-the-art equations for jet hydrodynamics and aerosol removal. Equations for variables like droplets population, size and velocity have been implemented. Based on the anticipated conditions in case of an SGTR severe accident sequence, comparisons of estimates from this new version (SPAR90-Jet) and the original one are set in terms of decontamination factor. Even though further work is still ahead, this work highlights how substantial particle retention at the pool inlet can reach under jet regime and how different aerosol removal mechanisms are with respect to the globule injection regime. (authors)

  3. Water jet/spray measurement analysis

    Science.gov (United States)

    Lala, G. G.

    1986-01-01

    The objective of this study was to provide analysis of data obtained under a previous contract entitled Characterization of Drop Spectra from High Volume Flow Water Jets. Measurements of drop spectra were obtained in the spray resulting from the breakup of high volume flow water jets from a variety of nozzle types. The drop spectra measurements were obtained from two drop spectrometers covering a range from 10 microns to 12 millimeters diameter. The task addressed was to select representative spectra from the individual tests and provide analyses in both numerical and graphical formats as outlined in the proposal. The intended application of these results is an evaluation of the feasibility of fog clearing by high volume water sprays. During the tests, a fog event occurred making it possible to test the concept of fog clearing. Visual range data and fog drop spectra were analyzed, with particular emphasis placed on the modification of these parameters due to the water spray.

  4. Compact Water Jet Propulsion System for a Marine Vehicle.

    Science.gov (United States)

    The invention is directed to an improved water jet propulsion system for a marine vehicle. The water jet propulsion system of the present invention...the vehicle hull and extending internally thereof, a water jet pump having an inlet end attached to the outlet end of the inlet duct, a motor for

  5. The Propulsive Force of the Water-jet to the Flying Weft in Water-jet Looms

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to study the propulsive force on the water-jet to the flying weft in water-jet looms, a dynamic model has been established. Based on the analysis and example testing, an experiential formula of the propulsive force of the water-jet to the flying weft is obtained for the first time. The formula will profit the further research of the water-jet weft insertion and the production of textile.

  6. Simulation and Experimental Study on Cavitating Water Jet Nozzle

    Science.gov (United States)

    Zhou, Wei; He, Kai; Cai, Jiannan; Hu, Shaojie; Li, Jiuhua; Du, Ruxu

    2017-01-01

    Cavitating water jet technology is a new kind of water jet technology with many advantages, such as energy-saving, efficient, environmentally-friendly and so on. Based on the numerical simulation and experimental verification in this paper, the research on cavitating nozzle has been carried out, which includes comparison of the cleaning ability of the cavitating jet and the ordinary jet, and comparison of cavitation effects of different structures of cavitating nozzles.

  7. Thermal aspects of ice abrasive water jet technology

    Directory of Open Access Journals (Sweden)

    Marko Jerman

    2015-08-01

    Full Text Available During the last few years, different research groups have been developing systems for the transition of abrasive water jet into ice abrasive water jet. The aim of this new technology is to make the technology cleaner from both practical and ecological points of view. Mineral abrasive is replaced with ice grains that melt away after the machining process, leaving the workpiece uncontaminated. Several different approaches to this technology were studied. Thermal aspects of integrating the ice abrasive water jet technology into commercially available machines were considered. The results and analyses of water temperature measurements on the ice abrasive water jet machine are presented in this article.

  8. Abrasive water jet: a complementary tool

    Directory of Open Access Journals (Sweden)

    Duarte, J. P.

    1998-04-01

    Full Text Available The abrasive water jet is a powerful cutting tool, whose main advantages lie in the absence of thermal effects and the capability of cutting highly thick materials. Compared with Laser, the abrasive water jet allows the cutting of a larger range of thicknesses and a wider variety of materials such as: ornamental stones, metals, polymers, composites, wood, glass and ceramics. The application of this technology has suffered an extensive growth, with successful applications in varied industrial sectors like the automotive, aerospace, textile, metalworking, ornamental stones, etc. The present communication aims at introducing the abrasive water jet as a complementary tool to laser cutting, presenting its advantages by showing some documented examples of pieces cut for different industries.

    O jacto de água abrasivo é uma poderosa ferramenta de corte, tendo como principais vantagens a ausência de processo térmico e permitir o corte de elevadas espessuras. Comparativamente com o laser o jacto de água abrasivo permite cortar uma maior gama de espessuras, e uma maior diversidade de materiais: rochas ornamentais, metais, polimeros, compósitos, madeiras, vidro e cerâmicos. A aplicação desta tecnologia tem sofrido um crescimento acentuado, existindo aplicações de sucesso nos mais variados sectores industriáis como a indústria automóvel, aeroespacial, têxtil, metalomecânica e rochas ornamentáis. Esta comunição pretende apresentar o corte por jacto de agua abrasivo como uma ferramenta de corte complementar ao corte por laser, apresentando as suas vantagens documentadas através de alguns exemplos de peças executadas para as diferentes indústrias.

  9. Laser-induced break-up of water jet waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Couty, P.; Hoffmann, P. [EPFL/STI/IOA/Advanced Photonics Laboratory, Lausanne BM, 1015, Lausanne (Switzerland); Spiegel, A.; Vago, N. [Department of Atomic Physics, Budapest University of Technology and Economics, Budafoki ut 8, 1111, Budapest (Hungary); Ugurtas, B.I. [EPFL/STI/IMHEF/Laboratory Fluid Mechanics, Lausanne, 1015, Lausanne (Switzerland)

    2004-06-01

    In this article, an optical method to control the break-up of high-speed liquid jets is proposed. The method consists of focusing the light of a pulsed laser source into the jet behaving as a waveguide. Experiments were performed with the help of a Q-switched frequency doubled Nd:Yag laser ({lambda}=532 nm). The jet diameter was 48 {mu}m and jet velocities from 100 to 200 m/s. To study the laser-induced water jet break-up, observations of the jet coupled with the high power laser were performed for variable coupling and jet velocity conditions. Experimentally determined wavelength and growth rate of the laser-generated disturbance were also compared with the ones predicted by linear stability theory of free jets. (orig.)

  10. Reliability of astrophysical jet simulations in 2D. On inter-code reliability and numerical convergence

    Science.gov (United States)

    Krause, M.; Camenzind, M.

    2001-12-01

    In the present paper, we examine the convergence behavior and inter-code reliability of astrophysical jet simulations in axial symmetry. We consider both pure hydrodynamic jets and jets with a dynamically significant magnetic field. The setups were chosen to match the setups of two other publications, and recomputed with the MHD code NIRVANA. We show that NIRVANA and the two other codes give comparable, but not identical results. We explain the differences by the different application of artificial viscosity in the three codes and numerical details, which can be summarized in a resolution effect, in the case without magnetic field: NIRVANA turns out to be a fair code of medium efficiency. It needs approximately twice the resolution as the code by Lind (Lind et al. 1989) and half the resolution as the code by Kössl (Kössl & Müller 1988). We find that some global properties of a hydrodynamical jet simulation, like e.g. the bow shock velocity, converge at 100 points per beam radius (ppb) with NIRVANA. The situation is quite different after switching on the toroidal magnetic field: in this case, global properties converge even at 10 ppb. In both cases, details of the inner jet structure and especially the terminal shock region are still insufficiently resolved, even at our highest resolution of 70 ppb in the magnetized case and 400 ppb for the pure hydrodynamic jet. The magnetized jet even suffers from a fatal retreat of the Mach disk towards the inflow boundary, which indicates that this simulation does not converge, in the end. This is also in definite disagreement with earlier simulations, and challenges further studies of the problem with other codes. In the case of our highest resolution simulation, we can report two new features: first, small scale Kelvin-Helmholtz instabilities are excited at the contact discontinuity next to the jet head. This slows down the development of the long wavelength Kelvin-Helmholtz instability and its turbulent cascade to smaller

  11. Testing of Commercial Cutting Heads for Abrasive Water Jet Technology

    OpenAIRE

    Klich, J. (Jiří); Hlaváček, P.; M. Zeleňák; Sitek, L. (Libor); Foldyna, J. (Josef)

    2013-01-01

    Five different cutting heads designed for cutting by high-speed abrasive water jet technology were tested from cutting ability point of view. Straight kerfs were cut in several metal materials by abrasive water jet. Material removal volume was determined as a measure of performance of specific cutting head. Quality of cutting surface was observed, too. Results are compared and discussed.

  12. Liver resection in children, using a water-jet.

    Science.gov (United States)

    Hata, Y; Sasaki, F; Takahashi, H; Ohkawa, Y; Taguchi, K; Une, Y; Uchino, J

    1994-05-01

    The water-jet method has been used during hepatic resection in children. The instrument cuts the hepatic tissue by means of a high-pressure fine water-jet, while the exposed intrahepatic vessels are spared injury. Physiological saline was used for the jet water, and pressure of 12 to 15 kilograms of force per square centimeter (kgf/cm2) through a 0.15-mm-diameter nozzle was found to be optimal for cutting the liver parenchyma. The authors evaluated the usefulness of the water-jet dissector (n = 8) during bisegmentectomy or trisegmentectomy in comparison to the Cavitron Ultrasonic Surgical Aspirator (CUSA) (n = 5). The mean operation time was 4.08 +/- 0.87 hours for the water-jet group and 5.08 +/- 1.33 hours for the CUSA group. The mean blood loss was 602 +/- 659 mL for the water-jet group and 1,036 +/- 521 mL for the CUSA group. Although there were no significant differences with respect to operation time, blood loss, or postoperative complications, the liver parenchyma was dissected more easily using the water-jet. The authors believe that the mechanical simplicity and safety of the water-jet method will lead to its more widespread use in liver resection in children.

  13. Analysis of a gas stratification break-up by a vertical jet using the GOTHIC code

    Energy Technology Data Exchange (ETDEWEB)

    Fernández-Cosials, Mikel Kevin; Jimenez, Gonzalo, E-mail: gonzalo.jimenez@upm.es; Lopez-Alonso, Emma

    2016-02-15

    Highlights: • Study of a light gas distribution with the GOTHIC code based on the OECD/NEA IBE-3. • Sensitivity analysis on turbulence model, discretization scheme and heat transfer. • The jet erosion phenomena is captured properly with a relatively coarse mesh. • Development of a tool to evaluate the influence of each parameter on the simulation. • Several recommendation on modeling a stratification break-up are included. - Abstract: During a severe accident in light water reactor (LWR), hydrogen concentration can overpass the flammability limits locally, so the correct simulation of its behavior during a release is critical. The capability assessment of computational fluid dynamics tools to calculate the hydrogen distribution under different conditions has been the focus of intense research worldwide. In this context, the OECD/NEA conducted an international benchmark exercise (IBE-3), which was focused on the break-up of a stratified layer of a light gas by a vertical jet. The participants performed their simulations before the experiment data was released. When the data was released, it was noticed that a combination of several parameters like the mesh, turbulence model or solver controls were responsible for the broad differences between the participants’ results. To obtain information about how each parameter affects the simulation, a post-test sensitivity analysis has been done by the UPM. In this paper, the IBE-3 experiment simulation with GOTHIC 8.0 is presented along with extensive sensitivity analyses of the relevant parameters. The first objective of the work is to test the capability of GOTHIC 8.0 to simulate properly a gas stratification break-up by a vertical jet with a relatively coarse mesh. The second objective of the paper is to relate each sensitivity parameter with each other and with the experiment through the Parameter Influence Chart, a helpful tool specially designed for this purpose.

  14. Interfacial structure in an air-water planar bubble jet

    Science.gov (United States)

    Sun, X.; Vasavada, S.; Choi, S. W.; Kim, S.; Ishii, M.; Beus, S. G.

    2005-04-01

    The objective of the current study is to better understand the interfacial structure and its development in an air-water planar bubble jet, as well as to provide a unique benchmark data set for a 3D thermal-hydraulic analysis code. Both flow visualization and local measurements were performed in three characteristic flow conditions at four elevations along a test section with a cross section of 200 mm in width and 10 mm in gap. A high-speed digital video camera was applied in the flow visualization study to capture the flow structures and bubble interaction phenomena, while a miniaturized four-sensor conductivity probe was used to acquire the time-averaged local void fraction, interfacial velocity, and bubble number frequency. Also, the interfacial area concentration and the averaged bubble Sauter mean diameter were obtained from the local measurements. The lateral bubble transport and bubble interaction mechanisms were clearly demonstrated in the acquired data.

  15. SUBMERGED IMPINGING JETS WITHIN A FINITE WATER DEPTH

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By use of the sheet of laser light and the trac-ing particle technology, flow visualization tests of complexflow structures for submerged impinging jets within finite wa-ter depths are conducted. Typical flow patterns of submergeimpinging jets are analysed by the singular topology method.In order to reveal the mechanism of these flows, the diffusivecharacteristics and turbulent fluctuations of submerged impin-ging jets are measured by the hot-film anemometer.

  16. Effect of Air Entrainment on Breakup of Plunging Liquid Jet into Water Pool

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyoungtak; Bang, Kwanghyun [Korea Maritime Univ., Busan (Korea, Republic of)

    2013-05-15

    The steam explosion intensity is largely dependent upon the degree of volumetric fractions of melt droplets and steam in the fuel-coolant mixture. The rate of melt jet breakup and droplet sizes are, therefore, the key physical parameters in the analysis of FCIs. In a recent OECD/NEA international program SERENA, the areas where research may be needed to reduce the level of uncertainties in the code predictions have been identified. The predicted void fractions in the mixture were generally much higher than experimental data and a deficiency in melt jet breakup modeling would be one of the primary causes. In this paper, an extended study of non-boiling liquid jet breakup from the previous jet breakup experiment is reported with an emphasis on the role of air entrainment by plunging liquid jet into water pool. An improved jet breakup model is also presented with comparison to the experimental data. Non-boiling liquid jet breakup experiment was conducted and the debris size was analyzed with a new jet breakup model with an emphasis on the role of air entrainment. The predicted debris size with consideration of entrained air showed good agreement with the experimental data.

  17. A lifting surface computer code with jet-in-crossflow interference effects. Volume 1: Theoretical description

    Science.gov (United States)

    Furlong, K. L.; Fearn, R. L.

    1983-01-01

    A method is proposed to combine a numerical description of a jet in a crossflow with a lifting surface panel code to calculate the jet/aerodynamic-surface interference effects on a V/STOL aircraft. An iterative technique is suggested that starts with a model for the properties of a jet/flat plate configuration and modifies these properties based on the flow field calculated for the configuration of interest. The method would estimate the pressures, forces, and moments on an aircraft out of ground effect. A first-order approximation to the method suggested is developed and applied to two simple configurations. The first-order approximation is a noniterative precedure which does not allow for interactions between multiple jets in a crossflow and also does not account for the influence of lifting surfaces on the jet properties. The jet/flat plate model utilized in the examples presented is restricted to a uniform round jet injected perpendicularly into a uniform crossflow for a range of jet-to-crossflow velocity ratios from three to ten.

  18. Experimental research on water-jet guided laser processing

    Science.gov (United States)

    Li, Ling; Wang, Yang; Yang, Lijun; Chu, Jiecheng

    2007-01-01

    The water-jet guided laser processing is a new compound micro-machining process in which the laser beam passes through the water-jet by full reflection onto the workpiece. In this paper, a new key component:the coupling unit was designed and which would form a long, slim, high-pressure and stable water-jet. The couple unit made the fluid field in the chamber symmetry; the coupling quality of the laser beam and the water-jet could be easily detected by CCD camera. For its excellent surface quality, the nozzle with a \\fgr 0.18mm hole got better machining effect than other nozzles. Aiming at finding optimum machining parameters, experiments were carried out. The results showed the attenuation of laser energy bore relation to water-jet stability. The energy intensity distributed over the water-jet cross section nearly homogeneous and the laser energy nearly did not decrease in long working distance. When water-jet pressure was high, efficient cooling of the workpiece prevented burrs, cracks and heat affected zone from forming. During cutting Si wafer process, nearly no cracking was found; Adjusting reasonable laser parameters grooving 65Mn, the machining accuracy would combine with the speed.

  19. The dental water jet: a product ahead of its time.

    Science.gov (United States)

    Ciancio, Sebastian G

    2009-03-01

    The dental water jet was invented by Dr. Gerald Moyer, a dentist, and John Mattingly, an engineer, in Ft. Collins, Colorado, in the late 1950s. The dental water jet, also known as an oral irrigator, was introduced to the dental profession in Texas during the 1962 Dallas Dental Convention. Numerous studies measuring the irrigator's efficacy in different cohorts have been published in peer-reviewed journals. The results of those studies are discussed in this article. The bulk of research has been conducted on one product (Waterpik dental water jet, Water Pik, Inc, Fort Collins, CO). This article is designed to provide dental professionals with the evidence essential to making an informed decision on the oral health benefits and expected outcomes of the dental water jet.

  20. Use of water jet instruments in gastrointestinal endoscopy.

    Science.gov (United States)

    Nakano, Toru; Sato, Chiaki; Sakurai, Tadashi; Kamei, Takashi; Nakagawa, Atsuhiro; Ohuchi, Noriaki

    2016-02-10

    In recent years, water jet instruments have been used in the field of gastrointestinal endoscopy, mainly in two clinical situations: Investigation and treatment under endoscopic view. Injecting water jet into the gastrointestinal lumen is helpful for maintaining a clear endoscopic view, washing away blood or mucous in the lumen or on the surface of the tip of the endoscope. This contributes to reducing time and discomfort of examination. Water jet technology is an alternative method for dissecting soft tissue; this method does not harm the small vessels or cause mechanical or thermal damage. However, its use in clinical settings has been limited to the transmucosal injection of water into the submucosal layer that elevates the mucosa to prepare for endoscopic mucosal resection or endoscopic submucosal dissection, instead of tissue dissection, which may occur because of the continuous water jet. A preclinical study has been conducted using a pulsed water jet system as an alternative method for submucosal dissection by reducing intraoperative water consumption and maintenance of dissection capability. This review introduces recent studies pertaining to using a water jet in gastrointestinal endoscopy and discusses future prospects.

  1. Thermal aspects of ice abrasive water jet technology

    OpenAIRE

    Marko Jerman; Henri Orbanić; Mihael Junkar; Andrej Lebar

    2015-01-01

    During the last few years, different research groups have been developing systems for the transition of abrasive water jet into ice abrasive water jet. The aim of this new technology is to make the technology cleaner from both practical and ecological points of view. Mineral abrasive is replaced with ice grains that melt away after the machining process, leaving the workpiece uncontaminated. Several different approaches to this technology were studied. Thermal aspects of integrating the ice a...

  2. Thermal aspects of ice abrasive water jet technology

    OpenAIRE

    Orbanić, Henri; Lebar, Andrej; Junkar, Mihael; Jerman, Marko

    2016-01-01

    During the last few years, different research groups have been developing systems for the transition of abrasive water jet into ice abrasive water jet. The aim of this new technology is to make the technology cleaner from both practical and ecological points of view. Mineral abrasive is replaced with ice grains that melt away after the machining process, leaving the workpiece uncontaminated. Several different approaches to this technology were studied. Thermal aspects of integrating the ice a...

  3. Impact welding of foils by water jets

    Energy Technology Data Exchange (ETDEWEB)

    Turgutlu, A.; Akyurt, M. [King Abdulaziz Univ., Jeddah (Saudi Arabia). Mechanical Engineering Dept.; Al-Hassani, S.T.S. [UMIST, Manchester (United Kingdom)

    1996-11-01

    Impact welding is a practical and economically feasible process for the solid-phase welding of similar and dissimilar metals. The versatile process is applicable to combinations of materials usually considered incompatible using more conventional joining methods. Thus, unlike with other spot welding methods, it is possible to use impact spot welding to join two metals of widely different melting points. Considerable research is needed to gain a thorough understanding of this process, its potential and possible new applications. Impact spot welding is similar to the familiar explosive welding process. Impact spot welding can be brought about by the action of a high-velocity object, such as projectile, on the material comprising the impacting object-target interface. The projectile impinging onto the top surface of a flyer plate at the target provides the energy of collision. Subsequently, the flyer plate moves with the projectile toward the base plate. A second impact occurs between the center of the bulge of the flyer plate and the base plate. The central collision of impact spreads radially out with an angle of collision. This oblique collision is an important feature of this process. The manner in which the flyer plate deforms due to the impact of a high-speed object is significant in defining spot welding geometry. The deformation is produced by a combination of elastic, plastic and hydrodynamic wave propagation involving normal, bending and shear stresses. Metallic materials are forcibly driven together by the use of an impactor in such a way that a strong metallurgical bond is formed. Therefore, the use of either explosives or impactors, which may be water jets or solid projectiles, is incidental. Bonding results, in general, only from the impact of the two or more materials. In this sense the resulting bonding may be called impact bonding instead of explosive bonding.

  4. An experimental and numerical study of water jet cleaning process

    CERN Document Server

    Guha, Anirban; Balachandar, Ram

    2010-01-01

    In this paper, we have experimentally, numerically and theoretically investigated the water jet cleaning process. Very high speed water jets (~80-200 m/s) are used in such cleaning operations. These jets diffuse in the surrounding atmosphere by the process of air entrainment and this contributes to the spreading of the jet and subsequent decay of pressure. Estimation of this pressure decay and subsequent placement of the cleaning object is of paramount importance in manufacturing and material processing industries. Also, the pressure distribution on the cleaning surface needs to be assessed in order to understand and optimize the material removal process. Experimental study is performed to understand the pressure characteristics. A Semi-empirical model for capturing the air entrainment has been added to the commercial CFD package FLUENT. The simulation results are validated against ours as well as previous experimental findings. The numerical results have shown that the optimal stand-off distance in cleaning ...

  5. Instability of water jet: Aerodynamically induced acoustic and capillary waves

    Science.gov (United States)

    Broman, Göran I.; Rudenko, Oleg V.

    2012-09-01

    High-speed water jet cutting has important industrial applications. To further improve the cutting performance it is critical to understand the theory behind the onset of instability of the jet. In this paper, instability of a water jet flowing out from a nozzle into ambient air is studied. Capillary forces and compressibility of the liquid caused by gas bubbles are taken into account, since these factors have shown to be important in previous experimental studies. A new dispersion equation, generalizing the analogous Rayleigh equation, is derived. It is shown how instability develops because of aerodynamic forces that appear at the streamlining of an initial irregularity of the equilibrium shape of the cross-section of the jet and how instability increases with increased concentration of gas bubbles. It is also shown how resonance phenomena are responsible for strong instability. On the basis of the theoretical explanations given, conditions for stable operation are indicated.

  6. Testing astrophysical radiation hydrodynamics codes with hypervelocity jet experiments on the nova laser

    Energy Technology Data Exchange (ETDEWEB)

    Estabrook, K; Farley, D; Glendinning, S G; Remington, B A; Stone, J; Turner, N

    1999-09-22

    Recent shock tube experiments using the Nova laser facility have demonstrated that strong shocks and highly supersonic flows similar to those encountered in astrophysical jets can be studied in detail through carefully controlled experiment. We propose the use of high power lasers such as Nova, Omega, and NIF to perform experiments on radiation hydrodynamic problems such as jets involving the multidimensional dynamics of strong shocks. High power lasers are the only experimental facilities that can reach the very high Mach number regime. The experiments will serve both as diagnostics of astrophysically interesting gas dynamic problems, and could also form the basis of test problems for numerical algorithms for astrophysical radiation hydrodynamic codes, The potential for experimentally achieving a strongly radiative jet seems very good.

  7. Air entrainment by plunging water jets

    NARCIS (Netherlands)

    Van de Sande, E.

    1974-01-01

    Gas entrainment caused by the impact of liquid jets upon liquid pool surfaces is a subject which has received too little attention. This well-known phenomenon,which occurs In nature and in numerous industrial operations, has only recently received interest from scientific workers. The influence on p

  8. Validating a Monotonically-Integrated Large Eddy Simulation Code for Subsonic Jet Acoustics

    Science.gov (United States)

    Ingraham, Daniel; Bridges, James

    2017-01-01

    The results of subsonic jet validation cases for the Naval Research Lab's Jet Engine Noise REduction (JENRE) code are reported. Two set points from the Tanna matrix, set point 3 (Ma = 0.5, unheated) and set point 7 (Ma = 0.9, unheated) are attempted on three different meshes. After a brief discussion of the JENRE code and the meshes constructed for this work, the turbulent statistics for the axial velocity are presented and compared to experimental data, with favorable results. Preliminary simulations for set point 23 (Ma = 0.5, Tj=T1 = 1.764) on one of the meshes are also described. Finally, the proposed configuration for the farfield noise prediction with JENRE's Ffowcs-Williams Hawking solver are detailed.

  9. The dental water jet: a historical review of the literature.

    Science.gov (United States)

    Jahn, Carol A

    2010-01-01

    The objective of this paper is to provide a broad overview of the predominant findings from research published on pulsating dental water jets over the last 45 years. The author performed a computerized MEDLINE search covering the years from 1962 to 2009, with 1962 chosen since it was the year the first dental water jet was introduced. Key words included "oral irrigator" and "oral irrigation." All past and current studies were reviewed and those that reflected original research were included. The article is not intended to provide an exhaustive detailed article review, but rather a broad review of predominant findings on currently available traditional pulsating dental water jets with no novelty features. The author makes no attempt to statistically analyze any of the data. Information reported in the article comes from the original investigator analysis and interpretation. The dental water jet is supported by a well-established body of evidence demonstrating the ability to remove plaque, reduce periodontal pathogens, gingivitis, bleeding and inflammatory mediators. The dental water jet is a viable tool for reducing bleeding and gingivitis in a wide variety of patients. Due to the extensive body of knowledge on this product, a meta-analysis or systematic review is warranted. Additional research is recommended to confirm plaque biofilm removal, its effectiveness in comparison to flossing and efficacy on patients with special oral or systemic health needs.

  10. Impurity profiles at the JET divertor targets compared with the DIVIMP code

    Energy Technology Data Exchange (ETDEWEB)

    Matthews, G.F.; Gottardi, N.A.C.; Harbour, P.J.; Horton, L.D.; Jackel, H.J.; De Kock, L.; Loarte, A.; Maggi, C.F.; O' Brien, D.P.J.; Simonini, R.; Spence, J.; Stamp, M.F.; Stott, P.E.; Summers, H.P.; Tagle, J.; Von Hellerman, M. (JET Joint Undertaking, Abingdon (United Kingdom)); Stangeby, P.C.; Elder, J.D. (Univ. Toronto, Inst. for Aerospace Studies, Downsview, Ontario (Canada))

    1992-12-01

    In this paper we describe the simulation of edge diagnostics in JET using the DIVIMP (divertor impurity) Monte Carlo code. We concentrate on two ohmic pulses and show how the results are influenced by a variety of modeling assumptions. Our results show that a wall source must be included to explain the diagnostic signals. The wall source is shown to be a significant source of impurity in the discharges studied and more generally. (orig.).

  11. Calculation of Water Supply to Hydraulic Jet Devices

    Directory of Open Access Journals (Sweden)

    M. V. Krautsou

    2006-01-01

    Full Text Available Dependence for calculation of working fluid supply to water-air ejector is proposed. The de­pendence has been derived via analysis and processing of data being obtained by experimental research of water-jet devices.

  12. Behaviour of water in jet fuel—A literature review

    Science.gov (United States)

    Baena-Zambrana, S.; Repetto, S. L.; Lawson, C. P.; Lam, J. K.-W.

    2013-07-01

    This review gives a detailed account of the different types of water contaminated fuel and the conditions that bring about each form of contamination. It also considers studies that have been done to date that investigate the physics behind the behaviour of water in different hydrocarbons and jet fuel at low temperatures.

  13. Comminution of Mica by Cavitation Abrasive Water Jet

    Institute of Scientific and Technical Information of China (English)

    GUO Chu-wen; LIU Lin-sheng; HAN Dong-tai; LI Ai-min; ZHANG Dong-hai

    2003-01-01

    The comminution of mica with an abrasive water jet is mainly based on three knids of effects, that is, high-speed collision, cavitating effect and shearing effect. Cavitation abrasive water jet was applied for the comminution of mica because cavitation abrasive water jet can make full use of the three effects mentioned above. Besides high speed impacting among particles,cavitation and shearing were also enhanced due to the divergent angle at the outlet of the cavitation nozzle.A JME-200CX transmission electron microscope was used for observing the size distribution of particles.Variance analysis on the experimental results indicates that the effect of cavitation is much more significant than that of collision.The effect of pressure on comminution results becomes less with the decrease of the particle size.

  14. Reaction thrust of water jet for conical nozzles

    Institute of Scientific and Technical Information of China (English)

    HUANG Guo-qin; YANG You-sheng; LI Xiao-hui; ZHU Yu-quan

    2009-01-01

    Clear knowledge on the reaction thrust of water jet is valuable for better design of water jet propulsion system.In this paper,theoretical,numerical and experimental studies were carried out to investigate the effects of the nozzle geometry as well as the inlet conditions on the reaction thrust of water jet.Comparison analyses reveal that the reaction thrust has a direct proportional relationship with the product of the inlet pressure,the square of flow rate and two-thirds power exponent of the input power.The results also indicate that the diameter of the cylinder column for the conical nozzle has great influence on the reaction thrust characteristics.In addition,the best values of the half cone angle and the cylinder column length exist to make the reaction thrust reach its maximum under the same inlet conditions.

  15. Experiment on Conical Pick Cutting Rock Material Assisted with Front and Rear Water Jet

    Directory of Open Access Journals (Sweden)

    Xiaohui Liu

    2015-01-01

    Full Text Available Conical picks are one kind of cutting tools widely used in engineering machinery. In the process of rock breaking, the conical pick bears great cutting force and wear. To solve the problem, a new method, conical pick assisted with high pressure water jet, could break rock effectively, and four different configuration modes of water jet were presented. In this paper, based on the analysis of the different water jet configuration’s advantages and disadvantages, experiments on front water jet, new typed rear water jet, and the combination of those two water jet configuration modes were conducted to study the assisting cutting performance and obtain the quantitative results.

  16. Major vascular injury from high-pressure water jet.

    Science.gov (United States)

    Harvey, R L; Ashley, D A; Yates, L; Dalton, M L; Solis, M M

    1996-01-01

    High-pressure water jets are used in industry as a cleaning and cutting tool. Penetrating injuries by these devices can produce minimal external evidence of extensive internal damage. We report a literature review and the case of a limb-threatening injury to the lower extremity caused by such a device.

  17. Optimal regime of jet fuel water impregnation by ultrasonic dispersion method

    Directory of Open Access Journals (Sweden)

    В. Г. Бережний

    2000-09-01

    Full Text Available Analyzed is the efficiency of existing method and devices of jet fuel water impregnation, their advantages and disadvantages. Proposed is a principal scheme of installation and optimal regime of jet fuel water impregnation by ultrasonic dispersion method

  18. The influence of water jet diameter and bone structural properties on the efficiency of pure water jet drilling in porcine bone

    NARCIS (Netherlands)

    Den Dunnen, S.; Tuijthof, G.J.M.

    2014-01-01

    Using water jets in orthopedic surgery to drill holes in bones can be beneficial due to the absence of thermal damage and the always sharp cut. To minimize operating time and the volume of water that is used, the efficiency (volume of removed bone per added volume of water) of the water jet should

  19. Experiment on Conical Pick Cutting Rock Material Assisted with Front and Rear Water Jet

    OpenAIRE

    Xiaohui Liu; Songyong Liu; Lie Li; Xinxia Cui

    2015-01-01

    Conical picks are one kind of cutting tools widely used in engineering machinery. In the process of rock breaking, the conical pick bears great cutting force and wear. To solve the problem, a new method, conical pick assisted with high pressure water jet, could break rock effectively, and four different configuration modes of water jet were presented. In this paper, based on the analysis of the different water jet configuration’s advantages and disadvantages, experiments on front water jet, n...

  20. [Application of helix water jet to parotid surgery].

    Science.gov (United States)

    Zhang, Dong-Kun; Guo, Zhu-Ming; Zhang, Quan; Zeng, Zong-Yuan; Chen, Fu-Jin; Chen, Wen-Kuan; Li, Hao; Wang, Shun-Lan

    2008-01-01

    Dissecting the facial nerves safely is an important guarantee for the accomplishment of parotidectomy and reduction of postoperative complications. This study was to explore the application of helix water jet to parotidectomy. Clinical data of 43 patients with parotid tumors, who received operation with helix water jet from Feb. 2004 to Feb. 2005 at Cancer Center of Sun Yat-Sen University, were analyzed. Meanwhile, traditional techniques in parotidectomy was performed in 36 patients (control group). Duration of operation, postoperative drainage volume, postoperative hospitalization, and occurrence of postoperative complications, such as facial nerve dysfunction and salivary fistula, of the 2 groups were compared. The postoperative drainage volume was significantly lower in water jet group than in control group [(9.89+/-3.74) mL vs. (12.15+/-2.11) mL, P0.05], postoperative hospitalization [(6.39+/-1.38) days vs. (6.45+/-1.05) days, P>0.05] between the two groups. Of the 43 patients in water jet group, 6 (14.0%) had grade II facial nerve dysfunction and 1 (2.3%) had grade III facial nerve dysfunction; of the 36 patients in control group, 5 (13.9%) had grade II facial nerve dysfunction, 2 (5.6%) had grade III facial nerve dysfunction, 1 (2.8%) had grade IV facial nerve dysfunction and 1 (2.8%) had salivary fistula. There was no permanent facial nerve dysfunction occurred in both groups. There was no significant difference in the occurrence of complications between the two groups. Nine patients who retained nervus auricularis magnus suffered from slight numbness symptom of auricular lobule. Use of helix water jet in parotid surgery is safe and confers some advantages over conventional methods of parotid dissection.

  1. Free jet water flow in Pelton turbines; Freistrahlstroemungen in Peltonturbinen

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.; Casey, M.

    2003-07-01

    This short article presents the results of experimental investigations made on the flow processes found in the jets of water in Pelton turbines. The results can be used to improve basic knowledge on the design of nozzles and the interaction between the jet and the cups on the Pelton turbine's wheel and thus help improve the efficiency of Pelton turbine systems. Brief details are given on the experimental arrangement and the measurement methods used, which included a Laser-Doppler-Anemometer system.

  2. Progress in numerical simulation of cavitating water jets

    Institute of Scientific and Technical Information of China (English)

    PENG Guoyi; SHMIZU Seiji

    2013-01-01

    This paper reviews recent progress made toward modeling of cavitation and numerical simulation of cavitating water jets.Properties of existing cavitation models are discussed and a compressible mixture flow method for the numerical simulation of highspeed water jets accompanied by intensive cavitation is introduced.Two-phase fluids media of cavitating flow are treated as a homogeneous bubbly mixture and the mean flow is computed by solving Reynolds-Averaged Navier-Stokes (RANS) equations for compressible fluid.The intensity of cavitation is evaluated by the gas volume fraction,which is governed by the compressibility of bubble-liquid mixture corresponding to the status of mean flow field.Numerical results of cavitating water jet issuing from an orifice nozzle are presented and its applicability to intensively cavitating jets is demonstrated.However,the effect of impact pressure caused by collapsing of bubbles is neglected,and effectively coupling of the present compressible mixture flow method with the dynamics of bubbles remains to be a challenge.

  3. 21 CFR 876.4650 - Water jet renal stone dislodger system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Water jet renal stone dislodger system. 876.4650... (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Surgical Devices § 876.4650 Water jet renal stone dislodger system. (a) Identification. A water jet renal stone dislodger system is a device used to...

  4. Influence of the transition area on efficiency of the water jet cutting

    OpenAIRE

    Říha, Zdeněk

    2013-01-01

    The transition area between big and small pipe diameter in the tool for water jet cutting creates subject of researching. Three kinds of transition areas were tested such as conical change, radius change and step change. The efficiency of the water jet cutting was evaluated for above mentioned transition areas. This work brings new possibilities for design of the water jet cutting tool.

  5. Machining human dentin by abrasive water jet drilling.

    Science.gov (United States)

    Kohorst, Philipp; Tegtmeyer, Sven; Biskup, Christian; Bach, Friedrich-Wilhelm; Stiesch, Meike

    2014-01-01

    The aim of this experimental in-vitro study was to investigate the machining of human dentin using an abrasive water jet and to evaluate the influence of different abrasives and water pressures on the removal rate. Seventy-two human teeth had been collected after extraction and randomly divided into six homogeneous groups (n=12). The teeth were processed in the area of root dentin with an industrial water jet device. Different abrasives (saccharose, sorbitol, xylitol) and water pressures (15 or 25 MPa) were used in each group. Dimensions of dentin removal were analysed using a stripe projection microscope and both drilling depth as well as volume of abrasion were recorded. Morphological analyses of the dentin cavities were performed using scanning electron microscopy (SEM). Both drilling depth and volume of abrasion were significantly influenced by the abrasive and the water pressure. Depending on these parameters, the drilling depth averaged between 142 and 378 μm; the volume of abrasion averaged between 0.07 and 0.15 mm3. Microscopic images revealed that all cavities are spherical and with clearly defined margins. Slight differences between the abrasives were found with respect to the microroughness of the surface of the cavities. The results indicate that abrasive water jet machining is a promising technique for processing human dentin.

  6. New potentional of high-speed water jet technology for renovating concrete structures

    Science.gov (United States)

    Bodnárová, L.; Sitek, L.; Hela, R.; Foldyna, J.

    2011-06-01

    The paper discusses the background and results of research focused on the action of a high-speed water jet on concrete with different qualities. The sufficient and careful removal of degraded concrete layers is very important for the renovation of concrete structures. High-speed water jet technology is one of the most common methods used for removing degraded concrete layers. Different types of high-speed water jets were tested in the experimental part. The classical technology of a single continuous water jet generated with one nozzle was tested as well as the technology of revolving water jets generated by multiple nozzles (used mainly for the renovation of larger areas). A continuous flat water jet and pulsating flat water jet were tested the first time, because the connection of a water jet with the acoustic generator of a pulsating jet offers new possibilities for the use of a water jet (see [1] and [2]). A water jet with such a modification is capable of efficient action and can even be used for cutting solid concrete with a relatively low consumption of energy. A flat pulsating water jet which can be newly used for renovation seems to be a promising technology.

  7. An Investigation of Different Material on Abrasive Water jet Machine

    Directory of Open Access Journals (Sweden)

    Vaibhav.j.limbachiya

    2011-07-01

    Full Text Available Abrasive water jet machine (AWJM is a nontraditional machining process. Abrasive water jet machining is a process of removal of material by impact erosion of high pressure (1500-4000 bar, high velocity of water and entrained high velocity of grit abrasives on a work piece. It’s a non-conventional machining process. At herefirst works on theoretical work after it make some experimental work and then analyses both results. Theoretical MRR found equal to the experimental MRR. In this paper investigation for three different materials like en8,acrylic and aluminum is carried out using Taguchi design of experiment method. Experiments are carried out using L25 Orthogonal array by varying Material traverse speed and abrasive mass flow rate for each material respectively. Anova carried out for identifies significant parameters.

  8. Jet Interactions with Magnetized Clouds. Preliminary Results from PIC Code and Large-Scale Hydrodynamic Simulations for AGN Jets

    Science.gov (United States)

    2010-01-01

    persists for at least a time, τ jet, of order the light travel time along its length, then τ jet ∼ 3x105 years for a 100 kpc jet. This yields a total...kinetic energy release of at least 9x1057 ergs over the ‘lifetime” of a large scale jet. A Mpc-scale jet traveling at 0.1c would suggest an energy of...is essential to understanding the man- ner in which the ambient medium (for exam- ple, from interstellar clouds) is accelerated and eventually

  9. Water jet indentation for local elasticity measurements of soft materials.

    Science.gov (United States)

    Chevalier, N R; Dantan, Ph; Gazquez, E; Cornelissen, A J M; Fleury, V

    2016-01-01

    We present a novel elastography method for soft materials (100Pa-100kPa) based on indentation by a μm-sized water jet. We show that the jet creates a localized deformation ("cavity") of the material that can be easily visualized. We study experimentally how cavity width and depth depend on jet speed, height, incidence angle and sample elasticity. We describe how to calibrate the indenter using gels of known stiffness. We then demonstrate that the indenter yields quantitative elasticity values within 10% of those measured by shear rheometry. We corroborate our experimental findings with fluid-solid finite-element simulations that quantitatively predict the cavity profile and fluid flow lines. The water jet indenter permits in situ local stiffness measurements of 2D or 3D gels used for cell culture in physiological buffer, is able to assess stiffness heterogeneities with a lateral resolution in the range 50-500μm (at the tissue scale) and can be assembled at low cost with standard material from a biology laboratory. We therefore believe it will become a valuable method to measure the stiffness of a wide range of soft, synthetic or biological materials.

  10. Characteristics of an actuator-driven pulsed water jet generator to dissecting soft tissue.

    Science.gov (United States)

    Seto, Takeshi; Yamamoto, Hiroaki; Takayama, Kazuyoshi; Nakagawa, Atsuhiro; Tominaga, Teiji

    2011-05-01

    This paper reports characteristics of an actuator-driven pulsed water jet generator applied, in particular, to dissect soft tissues. Results of experiments, by making use of high speed recording of optical visualization and varying nozzle diameter, actuator time interval, and their effects on dissection performance are presented. Jet penetration characteristics are compared with continuous water jet and hence potential assessment of pulsed water jets to clinical applications is performed.

  11. Effect of Inclined Water Jets on Tensile Strength of Bicomponent Hydroentangled Nonwoven Fabrics

    Institute of Scientific and Technical Information of China (English)

    Mbwana Suleiman Ndaro; JIN Xiang-yu; CHEN Ting; YU Chong-wen

    2007-01-01

    The effects of inclined water jets on bicomponent hydroentangled fabrics were investigated. The PET/COPET and PA6/PET hydroentangled fabrics were made by using designed inclined water jet apparatus. Effects of basis weight, water ts inclination angle and water jet pressure were discussed. The comparison was made on the average tensile strength of fabrics made by perpendicular water jets (0° inclination angle) and inclined water jets of 20° with pressure levels of 3 bars and 7 bars. It was found that increases of water jet pressure, the fabrics tensile strength were increased. Furthermore, increases of water jets inclination angle, fabric tensile strength of 60 g/m2 fabrics decreased while for 100 g/m2 fabrics tensile strength increased.

  12. High pressure water jet cutting and stripping

    Science.gov (United States)

    Hoppe, David T.; Babai, Majid K.

    1991-01-01

    High pressure water cutting techniques have a wide range of applications to the American space effort. Hydroblasting techniques are commonly used during the refurbishment of the reusable solid rocket motors. The process can be controlled to strip a thermal protective ablator without incurring any damage to the painted surface underneath by using a variation of possible parameters. Hydroblasting is a technique which is easily automated. Automation removes personnel from the hostile environment of the high pressure water. Computer controlled robots can perform the same task in a fraction of the time that would be required by manual operation.

  13. Numerical analysis on coal-breaking process under high pressure water jet

    Institute of Scientific and Technical Information of China (English)

    CHEN Jin-hua; LIANG Yun-pei; CHENG Guo-qiang

    2009-01-01

    Based on the theory of nonlinear dynamic finite element, the control equation of coal and water jet was acquired in the coal breaking process under a water jet. The calcu-lation model of coal breaking under a water jet was established; the fluid-structure cou-pling of water jet and coal was implemented by penalty function and convection calculation. The dynamic process of coal breaking under a water jet was simulated and analyzed by combining the united fracture criteria of the maximum tensile strain and the maximal shear strain in the two cases of damage to coal and damage failure to coal.

  14. 76 FR 6727 - Proposed Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To...

    Science.gov (United States)

    2011-02-08

    ... COMMISSION 18 CFR Part 410 Proposed Amendments to the Water Quality Regulations, Water Code and Comprehensive... and locations for public hearings on proposed amendments to its Water Quality Regulations, Water Code... amendments to the Commission's Water Quality Regulations, Water Code and Comprehensive Plan relating to...

  15. Experimental Investigation on the Material Removal of the Ultrasonic Vibration Assisted Abrasive Water Jet Machining Ceramics

    Directory of Open Access Journals (Sweden)

    Tao Wang

    2017-01-01

    Full Text Available The ultrasonic vibration activated in the abrasive water jet nozzle is used to enhance the capability of the abrasive water jet machinery. The experiment devices of the ultrasonic vibration assisted abrasive water jet are established; they are composed of the ultrasonic vibration producing device, the abrasive supplying device, the abrasive water jet nozzle, the water jet intensifier pump, and so on. And the effect of process parameters such as the vibration amplitude, the system working pressure, the stand-off, and the abrasive diameter on the ceramics material removal is studied. The experimental result indicates that the depth and the volume removal are increased when the ultrasonic vibration is added on abrasive water jet. With the increase of vibration amplitude, the depth and the volume of material removal are also increased. The other parameters of the ultrasonic vibration assisted abrasive water jet also have an important role in the improvement of ceramic material erosion efficiency.

  16. Water Jets from Bottles, Buckets, Barrels, and Vases with Holes

    Science.gov (United States)

    Lopac, Vjera

    2015-03-01

    Observation of the water jets flowing from three equidistant holes on the side of a vertical cylindrical bottle is an interesting and widely used didactical experiment illustrating the laws of fluids in motion. In this paper we analyze theoretically and numerically the ranges of the stationary water jets flowing from various rotationally symmetric vessels with holes, and their dependence on the height of the holes above the bottom, on thickness of the block supporting the vessel, and on different shapes of the vessel profile. This investigation was motivated by controversial descriptions and illustrations repeatedly found in physics textbooks and by the fact that previously in the physics teaching literature only the cylindrical vessel was treated.

  17. Experimental evaluation of water-jet dissection in endoscopic surgery.

    Science.gov (United States)

    Cuschieri, A

    1994-01-01

    The problems associated with high-velocity high-pressure water-jet dissection were investigated by in-vivo experiments using endoscopic equipment. Three problems were identified: backspray with fouling of the optic, poor control of the depth of cut, and detachment of tissue fragments and isolated cells which contaminate the operative field. The first two problems have been resolved by adoption of a hooded hand-piece and the incorporation of an adjustable back stop. A "dry" system which enables the evacuation of the back spray may deal with the problem of contamination of the operative field by detached cells but further in-vivo experiments are needed to confirm this. Until then, water-jet cutting is considered unsafe for both open and endoscopic surgery in patients undergoing extirpative procedures for cancer because of the risk of tumour seeding within the peritoneal cavity.

  18. Water jet: a promising method for cutting optical glass

    Science.gov (United States)

    Salinas-Luna, Javier; Machorro, Roberto; Camacho, Javier; Luna, Esteban; Nunez, Juan

    2006-05-01

    We present an alternative method for cutting optical glass. It works with a high-pressure fluid, carring abrasive powder. This technique offers some advantages over conventional methods that use diamond abrasive covered wires or disks. We make a critical comparison between those two techniques, characterizing cuts with interferometric, polarimetric, and Ronchi testing. The main feature of the water-jet technique is that it allows surface of any shape, already polished, to be cut safely.

  19. Simulation of a Synthetic Jet in Quiescent Air Using TLNS3D Flow Code

    Science.gov (United States)

    Vatsa, Veer N.; Turkel, Eli

    2007-01-01

    Although the actuator geometry is highly three-dimensional, the outer flowfield is nominally two-dimensional because of the high aspect ratio of the rectangular slot. For the present study, this configuration is modeled as a two-dimensional problem. A multi-block structured grid available at the CFDVAL2004 website is used as a baseline grid. The periodic motion of the diaphragm is simulated by specifying a sinusoidal velocity at the diaphragm surface with a frequency of 450 Hz, corresponding to the experimental setup. The amplitude is chosen so that the maximum Mach number at the jet exit is approximately 0.1, to replicate the experimental conditions. At the solid walls zero slip, zero injection, adiabatic temperature and zero pressure gradient conditions are imposed. In the external region, symmetry conditions are imposed on the side (vertical) boundaries and far-field conditions are imposed on the top boundary. A nominal free-stream Mach number of 0.001 is imposed in the free stream to simulate incompressible flow conditions in the TLNS3D code, which solves compressible flow equations. The code was run in unsteady (URANS) mode until the periodicity was established. The time-mean quantities were obtained by running the code for at least another 15 periods and averaging the flow quantities over these periods. The phase-locked average of flow quantities were assumed to be coincident with their values during the last full time period.

  20. Modified Dye for Water-Fast Ink-Jet Printing

    Institute of Scientific and Technical Information of China (English)

    Zheng Qingkang(郑庆康); Zhu Puxin(朱谱新); Wu Dacheng(吴大诚); Lewis DM.

    2001-01-01

    A quaternary ammonium compound containing amino acid residue was synthesized by Converting 3-chloro-2-hydroxy- propyalkyldimethylammonium chlorides into its epoxide derivatives, then attaching an amino acid to the epoxide derivatives synthesized a quaternary ammonium compound containing amino acid residue. Modified dyes were prepared by the ionotropy of anionic dyes with the quaternary ammonium compound containing amino acid residue. It was discovered that the modified dyes exhibited an excellent pH controllable solubility. These modified dyes have good water solubility at pH> 8.0, but they were water insoluble at pH < 6.5. On the printing paper, modified dyes in water-based ink-jet print ink could convert to water insoluble form and give prints excellent water fastness.

  1. Simulation with the COREDIV code of JET discharges with the ITER-like wall

    Energy Technology Data Exchange (ETDEWEB)

    Telesca, G., E-mail: g.telesca@fz-juelich.de [Department of Applied Physics, Ghent University, Gent (Belgium); Zagorski, R. [Institute of Plasma Physics and Laser Microfusion, EURATOM/IPPLM Association, Warsaw (Poland); Brezinsek, S. [IEK-4, FZ Jülich GmbH, Association EURATOM-FZJ, TEC, Jülich (Germany); Brix, M.; Flanagan, J. [EURATOM/CCFE Fusion Association, Culham, Abingdon, Oxon OX14 3DB (United Kingdom); Ivanova-Stanik, I. [Institute of Plasma Physics and Laser Microfusion, EURATOM/IPPLM Association, Warsaw (Poland); Lehnen, M. [IEK-4, FZ Jülich GmbH, Association EURATOM-FZJ, TEC, Jülich (Germany); Stamp, M. [EURATOM/CCFE Fusion Association, Culham, Abingdon, Oxon OX14 3DB (United Kingdom); Van Oost, G. [Department of Applied Physics, Ghent University, Gent (Belgium)

    2013-07-15

    ICRF heated L-mode pulses of JET with the new ITER like wall are simulated for the first time with the transport code COREDIV. The model, which couples self-consistently the core with the SOL as well as the main plasma with impurities, outputs, from a limited number of inputs as the heating power, the average density and the confinement time, the core temperatures and densities profiles, the effective ion charge Z{sub eff}, the power radiated, the W fluxes and concentration and the plasma parameters on the divertor. Due to the slab geometry of the SOL, the Be flux cannot be calculated self-consistently, but it is given as an input, according to spectroscopic measurements in the divertor. Comparison of simulations with experimental data both of the core and of the SOL is generally satisfactorily, with the exception of Z{sub eff}, possibly due to radiofrequency-specific effects, which are not accounted for in the model.

  2. Experimental Study on Abrasive Water Jet Machining of PZT Ceramic

    Science.gov (United States)

    Dhanawade, Ajit; Upadhyai, Ravi; Rouniyar, Arunkumar; Kumar, Shailendra

    2017-07-01

    This paper presents research work involved in abrasive water jet machining of PZT ceramic material. Process parameters namely stand-off distance, water pressure and traverse rate are considered in the present study. Response surface methodology approach is used to design the experiments. Relative significance of process parameters and their influence on kerf properties are identified on the basis of analysis of variance. It is found that water pressure and traverse rate are most significant parameters followed by stand-off distance. On the basis of experimental analysis, regression models are developed to predict kerf taper and depth of cut. The models are developed with respect to significant parameters, interaction and quadratic terms. It is found that model predictions are in congruence with experimental results. Multi-response optimization of process parameters is also performed using desirability approach in order to minimize kerf taper and maximize depth of cut. Kerf wall features of machined surfaces are observed using scanning electron microscope. The findings of present study are useful to improve kerf properties in abrasive water jet machining of PZT ceramic materials.

  3. Study and application of a high-pressure water jet multi-functional flow test system

    Science.gov (United States)

    Shi, Huaizhong; Li, Gensheng; Huang, Zhongwei; Li, Jingbin; Zhang, Yi

    2015-12-01

    As the exploration and development of oil and gas focus more and more on deeper formation, hydraulic issues such as high-pressure water jet rock breaking, wellbore multiphase flow law, cuttings carrying efficiency, and hydraulic fracturing technique during the drilling and completion process have become the key points. To accomplish related researches, a high-pressure water jet multi-functional flow test system was designed. The following novel researches are carried out: study of high-pressure water jet characteristics under confining pressure, wellbore multiphase flow regime, hydraulic pressure properties of down hole tools during jet fracturing and pulsed cavitation jet drilling, and deflector's friction in radial jet drilling. The validity and feasibility of the experimental results provided by the system with various test modules have proved its importance in the research of the high-pressure water jet and well completion technology.

  4. INVESTIGATION ON NEW TYPE OF DOUBLY BLENDING ABRASIVE WATER JET NOZZLE SYSTEM WITH HIGHER PERFORMANCE

    Institute of Scientific and Technical Information of China (English)

    ZHU Pailong; ZHOU Jinjin; TANG Dianbo

    2006-01-01

    Based on the two existing abrasive water-jet(AWJ) systems, the dia-jet (or pre-jet) and the post-jet, a new type of abrasive water-jet system is put forward, which combines the dia-jet's advantage, low operating system pressure, slender stream jet, and more concentrative abrasive in the blended stream, with merits of post-jet, the less sophisticate apparatus, successive supply of abrasives.The theoretic analysis is brought out in detail, and the nozzle system structure is concisely illustrated.Its relevant experiment results are demonstrated, proving that this new system is effective in various aspects, enlarging penetrating capability without raising system pressure, saving machining power supply, lessening energy loss, etc.

  5. Sodium spray and jet fire model development within the CONTAIN-LMR code

    Energy Technology Data Exchange (ETDEWEB)

    Scholtyssek, W. [Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Neutronenphysik und Reaktortechnik; Murata, K.K. [Sandia National Labs., Albuquerque, NM (United States)

    1993-12-31

    An assessment was made of the sodium spray fire model implemented in the CONTAIN code. The original droplet burn model, which was based on the NACOM code, was improved in several aspects, especially concerning evaluation of the droplet burning rate, reaction chemistry and heat balance, spray geometry and droplet motion, and consistency with CONTAIN standards of gas property evaluation. An additional droplet burning model based on a proposal by Krolikowski was made available to include the effect of the chemical equilibrium conditions at the flame temperature. The models were validated against single-droplet burn experiments as well as spray and jet fire experiments. Reasonable agreement was found between the two burn models and experimental data. When the gas temperature in the burning compartment reaches high values, the Krolikowski model seems to be preferable. Critical parameters for spray fire evaluation were found to be the spray characterization, especially the droplet size, which largely determines the burning efficiency, and heat transfer conditions at the interface between the atmosphere and structures, which controls the thermal hydraulic behavior in the burn compartment.

  6. Surface Analysis of Metal Materials After Water Jet Abrasive Machining

    Directory of Open Access Journals (Sweden)

    Pavel Polák

    2015-01-01

    Full Text Available In this article, we deal with a progressive production technology using the water jet cutting technology with the addition of abrasives for material removal. This technology is widely used in cutting various shapes, but also for the technology of machining such as turning, milling, drilling and cutting of threads. The aim of this article was to analyse the surface of selected types of metallic materials after abrasive machining, i.e. by assessing the impact of selected machining parameters on the surface roughness of metallic materials.

  7. Optimization of Profile and Material of Abrasive Water Jet Nozzle

    Science.gov (United States)

    Anand Bala Selwin, K. P.; Ramachandran, S.

    2017-05-01

    The objective of this work is to study the behaviour of the abrasive water jet nozzle with different profiles and materials. Taguchi-Grey relational analysis optimization technique is used to optimize the value with different material and different profiles. Initially the 3D models of the nozzle are modelled with different profiles by changing the tapered inlet angle of the nozzle. The different profile models are analysed with different materials and the results are optimized. The optimized results would give the better result taking wear and machining behaviour of the nozzle.

  8. Mechanical issues in laser and abrasive water jet cutting

    Science.gov (United States)

    Singh, Jogender; Jain, Sulekh C.

    1995-01-01

    In forging and other metal-working industries, lasers and abrasive water jets are being applied to cut a variety of metal products to improve productivity and reduce costs. As described in the following, both the processes have their unique cutting capabilities and characteristics. Before selecting one, however, users must be aware of how each technique influences the end product as well as its performance (e.g., high-cycle fatigue life). For this article, we examined the mechanics of these two cutting processes by studying their effects on Ti-6Al-4Vand A286 steel.

  9. Technical Possibilities of Noise Reduction in Material Cutting by Abrasive Water-jet

    OpenAIRE

    Radvanská, Agáta; Ergić, Todor; IVANDIĆ, Željko; Hloch, Sergej; Valiček, Jan; Mullerova, Jana

    2009-01-01

    The technical procedure of noise reduction in material cutting by abrasive water-jet is described in this paper. The paper is aimed at the implementation of technical possibilities of noise reduction in the cutting of material by abrasive water-jet technology. Both the theoretical and experimental investigations were performed to verify and specify the new findings in the reduction of acoustic sound pressure at abrasive water-jet machining of engineering materials. By means of identification,...

  10. NUMERICAL SIMULATION OF ROCK BREAKING MECHANISM WITH HIGH-PRESSURE WATER JET

    Institute of Scientific and Technical Information of China (English)

    NI Hong-jian

    2004-01-01

    Based on the analysis of experimental results, the rock damage model and the damage coupling model suitable for the whole rock breaking process with water jet were established with continuous damage mechanics and micro damage mechanics, and the numerical method was developed with continuum mechanics and the FEM theory. The rock breaking mechanism with water jet was studied systematically with numerical simulation for the first time in the field of water-jet rock breaking. The numerical results agree with the experimental ones which shows that the presented method is reasonable and can reflect the reality of water-jet rock breaking. The conclusion can be applied in practice.

  11. Experiment and simulation study of laser dicing silicon with water-jet

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Jiading; Long, Yuhong, E-mail: longyuhong@guet.edu.cn; Tong, Youqun; Yang, Xiaoqing; Zhang, Bin; Zhou, Zupeng

    2016-11-30

    Highlights: • The explosive melt expulsion could be a dominant process for the laser ablating silicon in liquids with ns-pulsed laser of 1064 nm irradiating. • Self-focusing phenomenon was found and its causes are analyzed. • SPH modeling technique was employed to understand the effect of water and water-jet on debris removal during water-jet laser machining. - Abstract: Water-jet laser processing is an internationally advanced technique, which combines the advantages of laser processing with water jet cutting. In the study, the experiment of water-jet laser dicing are conducted with ns pulsed laser of 1064 nm irradiating, and Smooth Particle Hydrodynamic (SPH) technique by AUTODYN software was modeled to research the fluid dynamics of water and melt when water jet impacting molten material. The silicon surface morphology of the irradiated spots has an appearance as one can see in porous formation. The surface morphology exhibits a large number of cavities which indicates as bubble nucleation sites. The observed surface morphology shows that the explosive melt expulsion could be a dominant process for the laser ablating silicon in liquids with nanosecond pulse laser of 1064 nm irradiating. Self-focusing phenomenon was found and its causes are analyzed. Smooth Particle Hydrodynamic (SPH) modeling technique was employed to understand the effect of water and water-jet on debris removal during water-jet laser machining.

  12. Phenol Oxidation by Combined Cavitation Water Jet and Hydrogen Peroxide

    Institute of Scientific and Technical Information of China (English)

    卢义玉; 刘勇; 夏彬伟; 左伟芹

    2012-01-01

    The paper presents results of phenol oxidized under the conditions of high temperature created during collapse of cavitation bubbles.The degradation efficiency has been greatly improved by using cavitation water jets combined with H2O2 as demonstrated in laboratory tests.Various factors affecting phenol removal ratio were ex-amined and the degradation mechanism was revealed by high performance liquid chromatography(HPLC).The re-sults showed that 99.85% of phenol was mineralized when phenol concentration was 100 mg·L-1 with pH value of 3.0,H2O2 concentration of 300 mg·L-1,confining pressure of 0.5 MPa,and pumping pressure of 20 MPa.The in-termediate products after phenol oxidation were composed of catechol,hydroquinone and p-benzoquinone.Finally,phenol was degraded into maleic acid and acetic acid.Furthermore,a dynamic model of phenol oxidation via cavi-tation water jets combined with H2O2 has been developed.

  13. Numerical simulation of high-speed turbulent water jets in air

    CERN Document Server

    Guha, Anirban; Balachandar, Ram

    2010-01-01

    Numerical simulation of high-speed turbulent water jets in air and its validation with experimental data has not been reported in the literature. It is therefore aimed to simulate the physics of these high-speed water jets and compare the results with the existing experimental works. High-speed water jets diffuse in the surrounding atmosphere by the processes of mass and momentum transfer. Air is entrained into the jet stream and the entire process contributes to jet spreading and subsequent pressure decay. Hence the physical problem is in the category of multiphase flows, for which mass and momentum transfer is to be determined to simulate the problem. Using the Eulerian multiphase and the k-\\epsilon turbulence models, plus a novel numerical model for mass and momentum transfer, the simulation was achieved. The results reasonably predict the flow physics of high-speed water jets in air.

  14. Experimental study of the water jet induced by underwater electrical discharge in a narrow rectangular tube

    Science.gov (United States)

    Koita, T.; Zhu, Y.; Sun, M.

    2017-03-01

    This paper reports an experimental investigation on the effects of explosion depth and tube width on the water jet induced by an underwater electrical discharge in a narrow rectangular tube. The water jet formation and bubble structure were evaluated from the images recorded by a high-speed video camera. Two typical patterns of jet formation and four general patterns of bubble implosion were observed, depending on the explosion depth and tube width. The velocity of the water jet was calculated from the recorded images. The jet velocity was observed to depend on not only the explosion depth and energy, but also on the tube width. We proposed an empirical formula defining the water jet velocity in the tube as a function of the tube width and explosion depth and energy.

  15. Experimental study of the water jet induced by underwater electrical discharge in a narrow rectangular tube

    Science.gov (United States)

    Koita, T.; Zhu, Y.; Sun, M.

    2016-05-01

    This paper reports an experimental investigation on the effects of explosion depth and tube width on the water jet induced by an underwater electrical discharge in a narrow rectangular tube. The water jet formation and bubble structure were evaluated from the images recorded by a high-speed video camera. Two typical patterns of jet formation and four general patterns of bubble implosion were observed, depending on the explosion depth and tube width. The velocity of the water jet was calculated from the recorded images. The jet velocity was observed to depend on not only the explosion depth and energy, but also on the tube width. We proposed an empirical formula defining the water jet velocity in the tube as a function of the tube width and explosion depth and energy.

  16. Numerical Study of Submerged Vertical Plane Jets Under Progressive Water Surface Waves

    Institute of Scientific and Technical Information of China (English)

    DAI Hui-chao; WANG Ling-ling

    2005-01-01

    When wastewater is discharged into a coastal area through an outfall system, it will always be subjected to the action of waves. It is important to study and quantify the mixing of the discharge with the ambient water so that accurate environmental impact assessment can be made for such discharge conditions. The present work aims to study the phenomenon of a plane jet discharged into water environment with regular waves. A 3D numerical model based on the full Navier-Stokes equations (NSE) in the σ-coordinate is developed to study the present problem. Turbulence effects are modeled by a subgrid-scale (SGS) model using the concept of large eddy simulation (LES). The operator splitting method is used to solve the modified NSE. The model has been applied to the simulation of three different cases of submerged plane jets with surface waves: jet with strong waves, jet with weak waves and jet without waves. Numerical results show that the waves enhance the mixing of the jet with the ambient fluid, and cause a periodic deflection of the jet. The size of the re-circulation is about 1.5~2.4 depth of water. The velocity profile of the jet is self-similar in the zone of established flow for both the pure jet and jet in wave circumstances. The spreading characteristic constant α is 0.100 and 0.105 for pure momentum jets with Re numbers 1025 and 2050. The value of α increases from 0.130 to 0.147 for a jet in weak and strong wave circumstances, showing that waves have an obvious effect on the mixing and dilution properties of jets. Numerical results are in good agreement with the experimental data for the cases of pure jets and jets with waves.

  17. Oil-in-water emulsification using confined impinging jets.

    Science.gov (United States)

    Siddiqui, Shad W; Norton, Ian T

    2012-07-01

    A confined impinging jet mixing device has been used to investigate the continuous sunflower oil/water emulsification process under turbulent flow conditions with oil contents between 5% (v/v) and 10% (v/v). Various emulsifiers (Tween20, Span80, Whey Protein, Lecithin and Sodium Dodecylsulphate) varying in molecular weights have been studied. Mean droplet sizes varied with the emulsifiers used and smallest droplets were obtained under fully turbulent flow regime, i.e. at the highest jet flow rate and highest jet Reynolds Number conditions. Sodium Dodecylsulfate (SDS) produced droplets in the range of 3.8 μm while 6 μm droplets were obtained with Whey Protein. Similar droplet sizes were obtained under fully turbulent flow conditions (610 mL/min; Reynolds Number=13,000) for oil content varying between 5% (v/v) and 10% (v/v). To investigate the smallest droplet size possible in the device, the emulsion was passed through the geometry multiple times. Multi-pass emulsification resulted in reduction in droplet size indicating that longer residence in the flow field under high shear condition allowed for breakage of droplets as well as the time for the emulsifier to stabilize the newly formed droplets, decreasing the impact of coalescence. This was confirmed by timescale analysis of the involved process steps for the droplet data obtained via experiments. Dependence of mean droplet size on the o/w interfacial tension and peak energy dissipation was also investigated. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Experimental study on hydrodynamic behaviors of high-speed gas jets in still water

    Institute of Scientific and Technical Information of China (English)

    Zhenqing Dai; Boyi Wang; Longxi Qi; Honghui Shi

    2006-01-01

    The present paper describes experimental investigation on the flow pattern and hydrodynamic effect of underwater gas jets from supersonic and sonic nozzles operated in correct- and imperfect expansion conditions. The flow visualizations show that jetting is the flow regime for the submerged gas injection at a high speed in the parameter range under consideration. The obtained results indicate that high-speed gas jets in still water induce large pressure pulsations upstream of the nozzle exit and the presence of shock-cell structure in the over-and under-expanded jets leads to an increase in the intensity of the jet-induced hydrodynamic pressure.

  19. Non-contact measurements of water jet spreading width with a laser instrument

    Science.gov (United States)

    Funami, Yuki; Hasuya, Ryo; Tanabe, Kotaro; Nakanishi, Yuji

    2016-08-01

    Jet spreading width is one of the important characteristics of water jets discharging into the air. Many researchers have dealt with measuring this width, and contact measuring methods on the water jet surface were employed in a lot of the cases. In order to avoid undesirable effects caused by the contact on the jet surface, we introduce non-contact measuring methods with a laser instrument to the measurements of jet spreading width. In measurements, a transmitter emits sheet-like laser beam to a receiver. The water jet between the transmitter and the receiver interrupts the laser beam and makes a shadow. The minimum and maximum values of the shadow width are measured. In addition, pictures of the water jet are taken with a scale, and the shadow width is measured from the pictures. The experiments on various needle strokes were performed. Three kinds of width consistent with the jet structure were obtained. In the results, it can be concluded that our non-contact measuring methods are feasible. The data of jet spreading widths and jet taper were obtained and are useful for future applications.

  20. Comparisons of Hydraulic Performance in Permanent Maglev Pump for Water-Jet Propulsion

    Directory of Open Access Journals (Sweden)

    Puyu Cao

    2014-08-01

    Full Text Available The operation of water-jet propulsion can generate nonuniform inflow that may be detrimental to the performance of the water-jets. To reduce disadvantages of the nonuniform inflow, a rim-driven water-jet propulsion was designed depending on the technology of passive magnetic levitation. Insufficient understanding of large performance deviations between the normal water-jets (shaft and permanent maglev water-jets (shaftless is a major problem in this paper. CFD was directly adopted in the feasibility and superiority of permanent maglev water-jets. Comparison and discussion of the hydraulic performance were carried out. The shaftless duct firstly has a drop in hydraulic losses (K1, since it effectively avoids the formation and evolution of the instability secondary vortex by the normalized helicity analysis. Then, the shaftless intake duct improves the inflow field of the water-jet pump, with consequencing the drop in the backflow and blocking on the blade shroud. So that the shaftless water-jet pump delivers higher flow rate and head to the propulsion than the shaft. Eventually, not only can the shaftless model increase the thrust and efficiency, but it has the ability to extend the working range and broaden the high efficiency region as well.

  1. Liquid Nitrogen and Water Jet Milling of Energetic Material Production Wastes

    Science.gov (United States)

    1996-05-01

    UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP017711 TITLE: Liquid Nitrogen and Water Jet Milling of Energetic...NITROGEN AND WATER JET MILLING OF ENERGETIC MATERIAL PRODUCTION WASTES Roger L. Schneider Rho Sigma Associates, Inc. Whitefish Bay, WI 53217-5968 USA 414

  2. Optimization of MGI in JET using the TOKES code and mitigation of RE damage for the first wall

    Energy Technology Data Exchange (ETDEWEB)

    Pestchanyi, S., E-mail: serguei.pestchanyi@kit.edu [Karlsruhe Institute of Technology, 76344, Karlsruhe (Germany); Boboc, A. [EURATOM/CCFE Fusion Association, Culham Science Centre Abingdon, Oxfordshire OX14 3DB (United Kingdom); Bazylev, B.; Landman, I. [Karlsruhe Institute of Technology, 76344, Karlsruhe (Germany)

    2014-10-15

    Highlights: •We simulated disruption mitigation using massive noble gas injection with the TOKES code. •The results of these simulations have been verified by comparison with JET experiments. •We have found that the amount of gas for triggering the thermal quench can be reduced 40 times. •We propose a special sacrificial diaphragm for mitigation of the wall damage with runaway electrons (RE). •The diaphragm erosion with RE beam has been roughly estimated. -- Abstract: Simulations of massive gas injection (MGI) into the JET plasma using noble gas (NG) have been performed using the TOKES code. The results of these simulations have been verified by comparison with JET experiment for disruption control. Further simulations performed showed that the amount of NG for triggering the thermal quench can be reduced 40 times comparing with the JET experiment. Such small amount of injected NG should generate runaway electrons (RE) with rather large probability. For mitigation of the wall damage with these RE, a special sacrificial diaphragm consisting of several W ‘nails’ with a characteristic thickness of 2 cm has been proposed. The diaphragm erosion with RE beam has been roughly estimated from above as less than 0.5 cm per disruption. Taking into account the plasma shielding may decrease erosion ∼10 times.

  3. EXPERIMENTAL INVESTIGATION INTO HOT WATER SLOT JETS WITH NEGATIVELY BUOYANCY IN CROSS FLOW

    Institute of Scientific and Technical Information of China (English)

    YANG Zhong-hua; HUAI Wen-xin; DAI Hui-chao

    2005-01-01

    An experiment was conducted to examine the near-field behavior of negatively buoyant planar jets in flowing environment. Hot water jet was projected downwards at different angles from a slot into a uniform cross flow. Micro Acoustic Doppler Velocimeter (Micro ADV) system is used to measure the velocity and turbulent fluxes of Reynolds stresses. The whole field temperatures were measured with fast response thermocouples. Pure jets experiments were made also to study the effect of buoyancy in negatively buoyant jets. It is found that the influenced area of hot jets is larger than which of pure jets when the jet angle is 90° and the influenced area of hot jets is smaller than which of pure jets when the jet angle is 45°. The difference is not obvious at 60° angle jets. This means that the rising of temperature has effect not only on negatively buoyancy, but also on the intensity of turbulence. The contrast of these two influences dominates the trend of jet flow.

  4. Design method of water jet pump towards high cavitation performances

    Science.gov (United States)

    Cao, L. L.; Che, B. X.; Hu, L. J.; Wu, D. Z.

    2016-05-01

    As one of the crucial components for power supply, the propulsion system is of great significance to the advance speed, noise performances, stabilities and other associated critical performances of underwater vehicles. Developing towards much higher advance speed, the underwater vehicles make more critical demands on the performances of the propulsion system. Basically, the increased advance speed requires the significantly raised rotation speed of the propulsion system, which would result in the deteriorated cavitation performances and consequently limit the thrust and efficiency of the whole system. Compared with the traditional propeller, the water jet pump offers more favourite cavitation, propulsion efficiency and other associated performances. The present research focuses on the cavitation performances of the waterjet pump blade profile in expectation of enlarging its advantages in high-speed vehicle propulsion. Based on the specifications of a certain underwater vehicle, the design method of the waterjet blade with high cavitation performances was investigated in terms of numerical simulation.

  5. A Study of the Rock Breaking Mechanism during Swirling Water Jet Drilling

    Institute of Scientific and Technical Information of China (English)

    NiHongjian; WangRuihe

    2004-01-01

    Based on an analysis of the factors affecting rock breaking and the coupling between rock and fluid during water jet drilling, the rock damage model and the damage-coupling model suitable for the whole rock breaking process under the water jet is established with continuous damage mechanics and micro-damage mechanics. The evolvement of rock damage during swirling water jet drilling is simulated on a nonlinear FEM and dynamic rock damage model, and a decoupled method is used to analyze the rock damage. The numerical results agree with the test results to a high degree, which shows the rock breaking ability of the swirling water jet is strong. This is because the jet particle velocity of the swirling water jet is three-dimensional, and its rock-breaking manner mainly has a slopping impact. Thus, the interference from returning fluid is less. All these aspects make it easy to draw and shear the rock surface. The rock breaking process is to break out an annular on the rock surface first, and then the annular develops quickly in both the radial and axial directions, the last part of the rock broken hole bottom is a protruding awl. The advantage of the swirling water jet breaking rock is the heavy breaking efficiency, large breaking area and less energy used to break rock per unite volume, so the swirling water jet can drill in a hole of a large diameter.

  6. Utilization of ultrasound to enhance high-speed water jet effects.

    Science.gov (United States)

    Foldyna, Josef; Sitek, Libor; Svehla, Branislav; Svehla, Stefan

    2004-05-01

    Continuous high-speed water jets are presently used in many industrial applications such as cutting of various materials, cleaning and removal of surface layers. However, there is still a need for further research to enhance the performance of pure water jets. An obvious method is to generate water jets at ultra-high pressures (currently up to 700 MPa). An alternate approach is to eliminate the need for such high pressures by pulsing of the jet. This follows from the fact that the impact pressure on a target generated by a slug of water is considerably higher than the stagnation pressure of a corresponding continuous jet. Ultrasonically forced modulation of a continuous stream of water represents the most promising method of pulsed jet generation because of its simplicity and practicality. A pulsed jet is generated by modulating a continuous stream of water by ultrasonic waves. A velocity transformer connected to a piezoelectric transducer is located axially inside a nozzle to induce longitudinal pulsations in the water. An extensive laboratory research program is in progress to understand the basic principles of the process and to optimize the nozzle design for several applications. The results reported in this paper show that the performance of such a pulsed jet is far superior to that of a continuous jet operating at the same parameters. Experimental results obtained with the ultrasonic vibration of a tip situated inside the nozzle indicate that using this technique one can achieve performance of the jet even order of magnitude higher in comparison to continuous jet at the same hydraulic parameters. Performance of ultrasonically modulated jets in cutting of various materials was tested in laboratory conditions. In this paper, results of measurement of dynamic pressure in the nozzle and force effects of modulated jets are presented together with results obtained in cutting of various materials using ultrasonically modulated water jets. The results are compared

  7. Development of underwater cutting system by abrasive water-jet

    Science.gov (United States)

    Demura, Kenji; Yamaguchi, Hitoshi

    1993-09-01

    The technology to cut objects in the ocean's depths with abrasive water jets was examined for possible application in view of the greater water depths and sophistication involved in work on the ocean floor today. A test model was developed to study this technology's safety and practicability. The test model was designed for use at great water depths and has functions and a configuration that are unlike equipment used on land. A continuous, stable supply of abrasive is a distinctive design feature. In land applications, there had been problems with plugged tubes and an uneven supply. For this reason, the abrasive was converted to slurry form, and a continuous pressurized tube pump system was adopted for supply to the nozzle head. Also, a hydraulic motor that does not employ oil or electric power was used to provide an underwater drive that is environment-friendly. The report outlines the technology's general design concept including its distinctive functions and its configuration for use at great depths, and the report provides great detail on the equipment.

  8. [The pulsed water jet for selective removal of bone cement during revision arthroplasty].

    Science.gov (United States)

    Honl, Matthias; Schwieger, Karsten; Carrero, Volker; Rentzsch, Reemt; Dierk, Oliver; Dries, Sebastian; Pude, Frank; Bluhm, Andrea; Hille, Ekkehard; Louis, Hartmut; Morlock, Michael

    2003-10-01

    Conventional tools used in prosthetic revision surgery have a limited range of action within the narrow cement mantle. Water jet cutting technology permits tiny and precisely controlled cuts, and may therefore be an alternative method of bone cement removal. Our study compares the cutting performance on bone cement (PMMA) and bone of a pulsed water jet and a continuous water jet. The aim of the study was to establish whether selective removal of PMMA is possible. 55 bone specimens (bovine femora) and 32 specimens of PMMA were cut with a continuous and a pulsed water jet at different pressures (40 MPa, 60 MPa) and pulse frequencies (0Hz, 50Hz, 250Hz). To ensure comparability of the results, the depths of cut were related to the hydraulic power of that part of the jet actually impinging on the material. While for PMMA the power-related depth of cut increased significantly with the pulse frequency, this did not apply to bone. The cuts produced in bone were sharp-edged. Since PMMA is more brittle than bone, the water jet caused cracks that enlarged further until particles of bone broke away. Although selective removal of PMMA without doing damage to the bone was not possible at the investigated settings of the jet parameters, the results do show that a pulsed water jet can cut bone cement much more effectively than bone. This is an important advantage over conventional non-selective tools for the removal of bone cement.

  9. Influence of aeration and initial water thickness on axial velocity attenuation of jet flows

    Institute of Scientific and Technical Information of China (English)

    Wang-ru WEI; Jun DENG; Bin LIU

    2013-01-01

    With the development of ski-jump energy dissipation for high and large discharge among the hydraulic projects,the effects of characteristics of water flow on energy dissipation are increasingly important.In the present study,the effects of aeration and the initial water thickness on axial velocity attenuation of jet flow were analyzed,using variance analysis and numerical calculated methods.From the analysis of test data,both of the air concentration and initial water thickness are sensitive factors for the axial velocity attenuation of jet flow along the axial way,and there is no significant interaction effect between the aeration and initial water thickness.Aeration has a more significant effect on the axial velocity attenuation of jet flow.Decreasing the initial water thickness of jet flow can reduce the length of jet core,and make the initial position of axial velocity attenuation closer to the nozzle exit.The numerical calculation results show that aeration can contribute to the enhancement of entrainment ability of jet flow,which may improve the interaction between jet flow and surroundings.For ski-jump energy dissipation among the hydraulic projects,combining aeration with decreasing initial water thickness of jet flow is an effective way to enhance the rate of axial velocity attenuation.

  10. Internal Corrosion Control of Water Supply Systems Code of Practice

    Science.gov (United States)

    This Code of Practice is part of a series of publications by the IWA Specialist Group on Metals and Related Substances in Drinking Water. It complements the following IWA Specialist Group publications: 1. Best Practice Guide on the Control of Lead in Drinking Water 2. Best Prac...

  11. Internal Corrosion Control of Water Supply Systems Code of Practice

    Science.gov (United States)

    This Code of Practice is part of a series of publications by the IWA Specialist Group on Metals and Related Substances in Drinking Water. It complements the following IWA Specialist Group publications: 1. Best Practice Guide on the Control of Lead in Drinking Water 2. Best Prac...

  12. Modeling of thermal and hydrodynamic aspects of molten jet/water interactions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.K.; Blomquist, C.A.; Spencer, B.W. (Argonne National Lab., IL (USA))

    1989-01-01

    In order to predict the effect of a fuel-coolant interaction after a hypothetical core-melt-down accident, a phenomenological model has been developed to describe the thermal and hydrodynamic behavior of a high-temperature molten jet when it interacts with saturated or subcooled water in a film boiling regime. The mechanisms of jet-material erosion were analyzed by Kelvin-Helmholtz instabilities on the coherent column and by boundary layer stripping on the leading edge. The heat transfer coefficient, vapor-film thickness, and net steam generation, all of which strongly affect the jet-breakup behavior, were solved analytically. It was found that the jet breakup (or erosion) depends strongly on the steam generation from the jet/water interaction. The jet-breakup length (i.e., penetration distance) was found to be sensitive to the initial jet temperature, water subcooling, and the physical state of the ambient water. The jet-breakup length and leading-edge velocity of the Wood's metal/water experiments are predicted well by the current model for the cases where a continuous vapor film exists. 14 refs., 13 figs.

  13. 75 FR 41106 - Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan to Update Water...

    Science.gov (United States)

    2010-07-15

    ... COMMISSION 18 CFR Part 410 Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan to Update Water Quality Criteria for Toxic Pollutants in the Delaware Estuary and Extend These Criteria to... proposed amendments to the Commission's Water Quality Regulations, Water Code and Comprehensive Plan...

  14. Fatal Penetrating Injuries Sustained by High-pressure Water Jet Unit.

    Science.gov (United States)

    Radojevic, Nemanja; Radnic, Bojana; Curovic, Ivana

    2015-11-01

    The high-pressure water jet unit is a generator of frequent burst of water jets. The water jet reaches very high speeds and is able to cause wounds similar to those of high-velocity projectiles. In the presented case, unusual fatal injuries sustained by water jet are presented. Operating with the unit, an untrained worker accidentally activated a high-pressure water jet unit, and the extremely high pressure of water liberated the jet unit from his hand and whirled it around him. A jet stream of water ran across his body and caused fatal penetrating injuries in the femoral region. The edges of the wound were mainly sharp with contusion rings on the skin beyond the edges. Exploring the inside of the canals during the autopsy, the left femoral artery and vein were found to be completely transected. The resemblance to a firearm entry wound and the severity of the internal injury make it a noteworthy entity. © 2015 American Academy of Forensic Sciences.

  15. Development of an Abrasive Water Jet Optimum Abrasive Flow Rate Model for Titanium Alloy Cutting (Preprint)

    Science.gov (United States)

    2006-05-01

    As the abrasive water jet (AWJ) is used in industry extensively, optimization of the process parameters that determine efficiency, economy and...quality of the process is becoming more and more important for its successful application. However, being a complicated cutting system, an abrasive water ... jet is characterized by a large number of process parameters, which include water pressure, orifice diameter, traverse rate, standoff distance, impact

  16. Assessment of three turbulence model performances in predicting water jet flow plunging into a liquid pool

    OpenAIRE

    Zidouni Kendil Faiza; Bousbia Salah Anis; Mataoui Amina

    2010-01-01

    The main purpose of the current study is to numerically investigate, through computational fluid dynamics modeling, a water jet injected vertically downward through a straight circular pipe into a water bath. The study also aims to obtain a better understanding of jet behavior, air entrainment and the dispersion of bubbles in the developing flow region. For these purposes, three dimensional air and water flows were modeled using the volume of fluid technique. The equations in question were fo...

  17. Study on Flow Field Characteristics of Nozzle Water Jet in Hydraulic cutting

    Science.gov (United States)

    Liao, Wen-tao; Deng, Xiao-yu

    2017-08-01

    Based on the theory of hydrodynamics, a mathematical model of nozzle water jet flow field in hydraulic cutting is established. By numerical simulation, the effects of nozzle convergence angle, nozzle outlet diameter and cylindrical section length on water jet flow impact is obtained, and the influence of three factors on the nozzle water jet flow field is analyzed. The optimal nozzle parameters are obtained by simulation as follows: convergence angle is 13 °, cylindrical section length is 8 mm and nozzle outlet diameter is 2 mm. Under this optimal nozzle parameters, hydraulic cutting has the best comprehensive effect.

  18. The Scour of Cohesive Soils by an Inclined Submerged Water Jet

    Science.gov (United States)

    1990-05-01

    t,. PPNi THl SCOUR OF COHESIVE SOILS BY AN INCLINED SUBMERGED WATER JET cv. A Thesis by JOSEPH DELBERT HEDGES Submitted to the Office of Graduate...Engineering 00 07 17 039 THE SCOUR OF COHESIVE SOILS BY A INCLINED SUBMERGED WATER JET Accession For N rS GRA&H DTIC TAB A Thesis by Distribution...SUBMERGED WATER JET I 3 A Thesis by I JOSEPH DELBERT HEDGES Approved as to style and content by: hn B. Herbich (Chair of Committee) !" / - "Is Aubrey L

  19. Experimental study on pressure and temperature distributions for low mass flux steam jet in subcooled water

    Institute of Scientific and Technical Information of China (English)

    YAN JunJie; WU XinZhuang; CHONG DaoTong

    2009-01-01

    A low mass flux steam jet in subcooled water was experimentally investigated. The transition of flow pattern from stable jet to condensation oscillation was observed at relatively high water temperature. The axial total pressures, the axial and radial temperature distributions were measured in the jet region. The results indicated that the pressure and temperature distributions were mainly influenced by the water temperature. The correlations corrected with water temperature were given to predict the dimen-sionless axial pressure peak distance and axial temperature distributions in the jet region, the results showed s good agreement between the predictions and experiments. Moreover, the self-similarity property of the radial temperature was obtained, which agreed well with Gauss distribution. In present work, all the dimensionless properties were mainly dependent on the water temperature but weakly on the nozzle size under a certain steam mass flux.

  20. Experiment and simulation study of laser dicing silicon with water-jet

    Science.gov (United States)

    Bao, Jiading; Long, Yuhong; Tong, Youqun; Yang, Xiaoqing; Zhang, Bin; Zhou, Zupeng

    2016-11-01

    Water-jet laser processing is an internationally advanced technique, which combines the advantages of laser processing with water jet cutting. In the study, the experiment of water-jet laser dicing are conducted with ns pulsed laser of 1064 nm irradiating, and Smooth Particle Hydrodynamic (SPH) technique by AUTODYN software was modeled to research the fluid dynamics of water and melt when water jet impacting molten material. The silicon surface morphology of the irradiated spots has an appearance as one can see in porous formation. The surface morphology exhibits a large number of cavities which indicates as bubble nucleation sites. The observed surface morphology shows that the explosive melt expulsion could be a dominant process for the laser ablating silicon in liquids with nanosecond pulse laser of 1064 nm irradiating. Self-focusing phenomenon was found and its causes are analyzed. Smooth Particle Hydrodynamic (SPH) modeling technique was employed to understand the effect of water and water-jet on debris removal during water-jet laser machining.

  1. Water jet dissection in neurosurgery: experimental results in the porcine cadaveric brain.

    Science.gov (United States)

    Oertel, Joachim; Gaab, Michael Robert; Knapp, Andreas; Essig, Harald; Warzok, Rolf; Piek, Juergen

    2003-01-01

    Water jet dissection is currently under investigation as a new tool for use in neurosurgical procedures. The safety of this instrument has already been demonstrated. However, precise data demonstrating highly accurate tissue dissection in the brain in combination with vessel preservation are still missing. In this study, 50 porcine cadaveric brains were dissected with the use of several nozzle types (80-150 in microm diameter, coherent straight or helically turned jet) and several levels of water jet pressure (1-40 bars). The dissection characteristics in various brain regions and the basilar artery were evaluated morphologically. The best results regarding reliable function, dissection accuracy, and the correlation of water jet pressure with dissection depth were obtained with the 120-microm Helix Hydro-Jet nozzle. An almost linear relationship of pressure increase with dissection depth was demonstrated. The dissection depth varied significantly up to threefold, depending on the area investigated (greatest resistance was in the brainstem, followed by hemispheres and then the cerebellum). Vessels including the basilar artery resisted pressure up to 15 bars in most cases, whereas the basilar artery was dissected significantly more often with higher pressure. The results indicate that 1) use of the water jet enables very precise and reliable brain parenchyma dissection with vessel preservation under conditions corresponding to the clinical situation, and 2) the nozzle type and water jet pressure must be selected carefully according to the brain area and tissue targeted. This study provides the morphological basis for further research with the use of the water jet technique in the brain. The water jet's characteristics may make this device a useful addition to the neurosurgical armamentarium.

  2. Research on Discharge Circuit of Electro-Hydraulic Power Impulse Water Jets

    Science.gov (United States)

    Wang, Zhaohui; Gao, Quanjie; Wang, Wei; Liao, Zhenfang

    2012-01-01

    Electro-hydraulic power impulse water jets can convert the shock wave generated in the liquid by discharging into mechanical energy, and it has been widely used in material forming, surface cleaning, pipeline dirt cleaning and ore breaking process. Compared with the traditional high pressure water jets, the energy utilization of electro-hydraulic power impulse water jets is up to 80% while the water consumption is reduced by 40-55%. This paper has taken electro-hydraulic power impulse water jets as the research object, employed obtaining the maximum pressure of compression impulse matrix surface as the research goal, studied in depth the equivalent discharge circuit, characteristic equation and the relationship between the electrical parameters of the electro-hydraulic power impulse discharge circuit and built the calculation method of the voltage, the inductance, the capacitance and the electrode spacing parameter of electro-hydraulic power impulse water jets discharge circuit. So, it will provide important theoretical basis for further studies of electro-hydraulic power impulse technology and the existing water jets device.

  3. Utilization of abrasive water jet for cutting parts of intricate shapes

    Directory of Open Access Journals (Sweden)

    Al-Qawabah Safwan M. A.

    2017-01-01

    Full Text Available As early as 1974 the British Hydrodynamic Research Association, BHRA, held the First International Conference on Cutting by Water Jets. The subject was at its early stages. Since then a large amount of research work has been carried out and the process has been greatly developed. In this paper, utilization of water jets for flexible cutting parts of intricate shapes in steel plates and granite is presented and discussed.

  4. AIRBOAT NOISE REDUCTION AND IMPELLER DESIGN FOR WATER JET PROPULSION SYSTEMS

    Science.gov (United States)

    quieter than the original wooden propeller. The second part of the report concerns the design of impellers for use in water jet propulsion system for...shallow draft boats. The impellers in a commercial water jet system used by the Army did not perform as anticipated. The report describes the design of a new impeller and guide vanes to replace those in the commercial unit.

  5. Droplet evaporation in water jet at the motion through high temperature gases

    Directory of Open Access Journals (Sweden)

    Strizhak Pavel A.

    2014-01-01

    Full Text Available Heat and mass transfer model for the numerical investigation of the evaporation process of a single droplet in water jet when moving through high temperature gases was developed. The integral characteristics of the process under investigation were calculated. The macroscopic regularities of water droplet evaporation, as elements of jet, in the high temperature gas mixture (as exemplified by combustion products of typical condensed substances were determined.

  6. STABILITY AND MIXING CHARACTER FOR BUOYANT JETS IN QUIESCENT SHALLOW WATER

    Institute of Scientific and Technical Information of China (English)

    ZENG Yu-hong

    2005-01-01

    The near field stability and mixing characteristics of buoyant jets produced by thermal diffuse in quiescent shallow water are investigated numerically to predict under what combinations of discharge and ambient characteristics the near field will be stable or unstable.Analyses for different discharging types show that the discharge stability is purely dependent on the near-field behavior of the jets, or the dynamic interaction of the buoyant jet region, the surface impingement region and the internal hydraulic jump region, and is independent of the far-field geometry of the receiving water.The stability criterion is a function of the relative submerged depth, and source densimetric Froude number.

  7. Analysis of solidification of molten metal jet in the in-rotating-water spinning process

    Energy Technology Data Exchange (ETDEWEB)

    Shimaoka, M. (Nara National College of Technology, Nara (Japan)): Onaka, I. (Osaka University, Osaka (Japan))

    1991-04-01

    Cooling and solidification processes of molten metal jet in an in-rotating-water spinning process were studied on Cu {sub 85} Be {sub 11} Fe {sub 4}(at%) alloy at ejection temperatures of 1,340-1,540 K, jet diameters of 0.1-0.19 mm and water subcooling temperatures of 60-90 K. As a result, separation of water was observed around the jet, and the length of water separation along the wire increased with decreasing wettability between the wire and water due to formation of a vapor film around the jet by boiling. The temperature profile calculated from the value of a heat transfer coefficient obtained by an Epstein and Hauser {prime} s equation in the region of water separation almost agreed with that estimated from brightness of the jet on the basis of a photographic paper. Cooling rates of the jet during solidification were estimated to be in the range of 10 {sup 4}-10 {sup 5} K/s from numerical simulation. 23 refs., 10 figs.

  8. Evaluation and Modeling of Camel Thorn (Alhagi Maurorum Weed Cutting by Water Jet

    Directory of Open Access Journals (Sweden)

    M Naghipour Zade Mahani

    2014-04-01

    Full Text Available Due to the importance of weed control and the limitations of mechanical methods in some places, in this research the water jet cutting for weed control was investigated. The cutting tests were performed on camel thorn weed in Shahid Bahonar university of Kerman. The water jet pressure of 90 bars was achieved with the aid of a suitable pump. The cutting time was studied in a completely randomized factorial design experiment (CRD with five replications. Factors of experiments are: stem diameter in 2 levels (smaller and larger than 5 mm, distance of spraying jet from weeds in 3 levels (10, 20 and 30 cm and two types of plant holders: blade and plate. The results showed that stem diameter and jet distance from the weed stem had significant effects on cutting time (at the 1%. The mean comparison of parameters showed that with increase of stem diameter the cutting time increased and any increase in jet distance from the weeds decreased the cutting time linearly with R2=0.96 and R2=0.99 for small and large diameter weeds, respectively. The minimum cutting time was measured at 30 cm of the jet from small diameter of stems. A multivariate linear regression model was also proposed for cutting weed parameters. It can be concluded that due to the flexibility of water jet cutting for restricted places, hydrodynamic control of weeds is proposed as a complementary method and sometimes a competing substitute method.

  9. NUMERICAL SIMULATION STUDY ON ROCK BREAKING MECHANISM AND PROCESS UNDER HIGH PRESSURE WATER JET

    Institute of Scientific and Technical Information of China (English)

    NI Hong-jian; WANG Rui-he; ZHANG Yan-qing

    2005-01-01

    The numerical simulation method to study rock breaking process and mechanism under high pressure water jet was developed with the continuous mechanics and the FEM theory. The rock damage model and the damage-coupling model suited to analyze the whole process of water jet breaking rock were established with continuum damage mechanics and micro damage mechanics. The numerical results show the dynamic response of rock under water jet and the evolvement of hydrodynamic characteristic of jet during rock breaking is close to reality, and indicates that the body of rock damage and breakage under the general continual jet occurs within several milliseconds, the main damage form is tensile damage caused by rock unload and jet impact, and the evolvement of rock damage shows a step-change trend. On the whole,the numerical results can agree with experimental conclusions, which manifest that the analytical method is feasible and can be applied to guide the research and application of jet breaking rock theory.

  10. 18 CFR 410.1 - Basin regulations-Water Code and Administrative Manual-Part III Water Quality Regulations.

    Science.gov (United States)

    2010-04-01

    ... Code and Administrative Manual-Part III Water Quality Regulations. 410.1 Section 410.1 Conservation of Power and Water Resources DELAWARE RIVER BASIN COMMISSION ADMINISTRATIVE MANUAL BASIN REGULATIONS; WATER CODE AND ADMINISTRATIVE MANUAL-PART III WATER QUALITY REGULATIONS § 410.1 Basin regulations—Water Code...

  11. Flow structure of conical distributed multiple gas jets injected into a water chamber

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Jiajun; Yu, Yonggang [Nanjing University of Science and Technology, Nanjing (China)

    2017-04-15

    Based on an underwater gun firing project, a mock bullet with several holes on the head was designed and experimented to observe the combustion gas injected into a cylindrical water chamber through this mock bullet. The combustion gas jets contain one vertical central jet and 4 to 8 slant lateral jets. A high speed camera system was used to record the expansion of gas jets in the experimental study. In numerical simulations, the Euler two-fluid model and volume of fluid method were adopted to describe the gas-liquid flow. The results show the backflow zone in lateral jet is the main factor influencing the gas-liquid turbulent mixing in downstream. On cross sections, the gas volume fraction increased with time but the growth rate decreased. With a change of nozzle structure, the gas fraction was more affected than the shock structure.

  12. Simulation of Water Chemistry using and Geochemistry Code, PHREEQE

    Energy Technology Data Exchange (ETDEWEB)

    Chi, J.H. [Korea Electric Power Research Institute, Taejeon (Korea)

    2001-07-01

    This report introduces principles and procedures of simulation for water chemistry using a geochemistry code, PHREEQE. As and example of the application of this code, we described the simulation procedure for titration of an aquatic sample with strong acid to investigate the state of Carbonates in aquatic solution. Major contents of this report are as follows; Concepts and principles of PHREEQE, Kinds of chemical reactions which may be properly simulated by PHREEQE, The definition and meaning of each input data, An example of simulation using PHREEQE. (author). 2 figs., 1 tab.

  13. [Usefulness of pulsed water jet in dissecting sphenoid ridge meningioma while preserving arteries].

    Science.gov (United States)

    Endo, Toshiki; Nakagawa, Atsuhiro; Fujimura, Miki; Sonoda, Yukihiko; Shimizu, Hiroaki; Tominaga, Teiji

    2014-11-01

    We report the utility of a pulsed water jet device in meningioma surgery. The presented case is that of a 61-year-old woman with left visual disturbance. MRI demonstrated heterogeneously enhanced mass with intratumoral hemorrhage, indicating sphenoid ridge meningioma on her left side. The tumor invaded the cavernous sinus and left optic canal, engulfing the internal carotid artery in the carotid cistern and encased middle cerebral arteries. During the operation, the pulsed water jet device was useful for dissecting the tumor away from the arteries since it was safe in light of preserving parent arteries. The jet did not cause any vascular injury and did not induce vasospasm as shown by postoperative symptomatology and MRIs. With the aid of pulsed water jet, we could achieve total resection of the tumor except for the piece within the cavernous sinus. The patient had no new neurological deficits after the operation. We consider the pulsed water jet as a useful device, especially when the need to dissect meningioma from parent arteries exists. The jet can help neurosurgeons simultaneously achieve tumor resection and preservation of blood vessels.

  14. Depth of penetration of bubbles entrained by a plunging water jet

    Science.gov (United States)

    Clanet, Christophe; Lasheras, Juan C.

    1997-07-01

    A model is proposed to predict the depth of penetration of the air bubbles entrained by a round water jet impacting into a flat, liquid pool. This depth is shown to be determined only by the initial jet momentum and by the non-monotonic nature of the bubble terminal velocities as a function of their size. The model is shown to be in excellent agreement with measurements of the depth and width of penetration of the bubbles performed over a wide range of jet diameters, velocities, and plunging angles.

  15. FILM-30: A Heat Transfer Properties Code for Water Coolant

    Energy Technology Data Exchange (ETDEWEB)

    MARSHALL, THERON D.

    2001-02-01

    A FORTRAN computer code has been written to calculate the heat transfer properties at the wetted perimeter of a coolant channel when provided the bulk water conditions. This computer code is titled FILM-30 and the code calculates its heat transfer properties by using the following correlations: (1) Sieder-Tate: forced convection, (2) Bergles-Rohsenow: onset to nucleate boiling, (3) Bergles-Rohsenow: partially developed nucleate boiling, (4) Araki: fully developed nucleate boiling, (5) Tong-75: critical heat flux (CHF), and (6) Marshall-98: transition boiling. FILM-30 produces output files that provide the heat flux and heat transfer coefficient at the wetted perimeter as a function of temperature. To validate FILM-30, the calculated heat transfer properties were used in finite element analyses to predict internal temperatures for a water-cooled copper mockup under one-sided heating from a rastered electron beam. These predicted temperatures were compared with the measured temperatures from the author's 1994 and 1998 heat transfer experiments. There was excellent agreement between the predicted and experimentally measured temperatures, which confirmed the accuracy of FILM-30 within the experimental range of the tests. FILM-30 can accurately predict the CHF and transition boiling regimes, which is an important advantage over current heat transfer codes. Consequently, FILM-30 is ideal for predicting heat transfer properties for applications that feature high heat fluxes produced by one-sided heating.

  16. Study of Atomization of a Water Jet by High-Intensity Aerial Ultrasonic Waves

    Science.gov (United States)

    Ito, Youichi

    2001-05-01

    An experimental study has been carried out on the atomization of a water jet by aerially radiating it with high-intensity ultrasonic waves. A sound source that enables the linear generation of high-intensity aerial ultrasonic waves (frequency: approximately 20 kHz) is combined with a cylindrical reflection plate in order to create a standing-wave sound field. An attempt has been made to atomize a water jet of 1 mm diameter by passing it through the above sound field at a velocity of approximately 30 m/s. It has been clarified that nodes of sound pressure in the standing-wave sound field are effective for the atomization of a water jet. In addition, the atomizing phenomenon of a water jet has been observed precisely. The relation between the intensity of sound waves required for atomization and the radiation duration has also been clarified. Even the radiation of sound waves for only 2 ms atomizes water. This suggests that a very fast water jet at 300-500 m/s might be atomized.

  17. A new system for cutting brain tissue preserving vessels: water jet cutting.

    Science.gov (United States)

    Terzis, A J; Nowak, G; Rentzsch, O; Arnold, H; Diebold, J; Baretton, G

    1989-01-01

    The water jet cutting system allows transaction and dissection of biological structures with little bleeding. Structures of higher tissue rigidity remain unchanged while softer tissues are mechanically dissected. In brain tissue, all vessels larger than 20 microns are left intact after the passage of the jet stream with a pressure of up to 5 bar, and therefore vessels can be isolated selectively from the surrounding tissue. Oedema is present adjacent to the cut and no increase of temperature occurs.

  18. A study of flow and initial stage of water condensation in the exhaust jet of the aircraft turbofan engine

    OpenAIRE

    Lobanova, Maria,; Tsirkunov, Yury,

    2013-01-01

    The paper describes the results of numerical study of flow in the exhaust jet of turbofan engine CFM 56-3. Influence of computational domain decomposition, grid refinement and flow model on the jet flow field is discussed. Special attention is payed to simulation of nucleation and condensation processes in the exhaust jet. Growth of water clusters in the jet and cluster distribution in size are obtained.; International audience; The paper describes the results of numerical study of flow in th...

  19. Full factorial DOE to determine the influence of the process parameters in cleaning water jets used in sewer cleaning

    OpenAIRE

    Medan Nicolae; Lobontiu Mircea; Banica Mihai

    2017-01-01

    Industrial cleaning is a classic application of water jets technology. In the late 1950s, when reliable high pressure pumps were built, the usage of water jets spread widely in the field of pipes and sewerage cleaning. In our particular case, water jets using pressure between 100 and 200 bars are being used. The operational behaviour of these systems is dependent on the process parameters, which can vary, causing variations in the impact force. The experiment consists in the research method u...

  20. Numerical Simulation of Rock Fragmentation under the Impact Load of Water Jet

    Directory of Open Access Journals (Sweden)

    Jiang Hongxiang

    2014-01-01

    Full Text Available To investigate the rock fragmentation and its influence factors under the impact load of water jet, a numerical method which coupled finite element method (FEM with smoothed particle hydrodynamics (SPH was adopted to simulate the rock fragmentation process by water jet. Linear and shock equations of state were applied to describe the dynamic characteristics of rock and water, respectively, while the maximum principal stress criterion was used for the rock failure detection. The dynamic stresses at the selected element containing points in rock are computed as a function of time under the impact load of water jet. The influences of the factors of boundary condition, impact velocity, confining pressure, and structure plane on rock dynamic fragmentation are discussed.

  1. Development of spherical fine powders by high-pressure water atomization using swirl water jet; Senkaisui jet wo mochiita koatsusui atomize ni yoru kyujo bifun no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kikukawa, M.; Matsumoto, S.; Inaba, T.; Iwatsu, O.; Takeda, T. [Fukuda Metal Foil and Powder Co. Ltd., Kyoto (Japan)

    2000-05-15

    In order to obtain spherical fine powders, a new high-pressure water atomization method using swirl water jet was developed. In this paper the effects of jet swirl angle ({omega}) upon the properties of powders were investigated. Cu-10 mass%Sn alloy was atomized by this method at the constant water pressure of 83.3 MPa and constant metal orifice diameter of 4mm, while {omega} was varied from 0 to 0.18 rad. Median diameter of the powder by the laser diffraction method (D{sub 50}) decreased from 12.5 {mu}m to 7.5{mu}m with increasing {omega}, and this corresponded to Fisher average diameter (D{sub FS}) at about w=0.18 rad. The apparent and tap density of the powder increased about 1 and 1.5 Mg/m{sup 3} respectively, and the particle shape observed by SEM became spherical with increasing {omega}. (author)

  2. Degradation of C.I. Reactive Red 2 through photocatalysis coupled with water jet cavitation.

    Science.gov (United States)

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2011-01-15

    The decolorization of an azo dye, C.I. Reactive Red 2 was investigated using TiO(2) photocatalysis coupled with water jet cavitation. Experiments were performed in a 4.0 L solution under ultraviolet power of 9 W. The effects of TiO(2) loading, initial dye concentration, solution pH, geometry of cavitation tube, and the addition of anions on the degradation of the dye were evaluated. Degradation of the dye followed a pseudo-first order reaction. The photocatalysis coupled with water jet cavitation elevated degradation of the dye by about 136%, showing a synergistic effect compared to the individual photocatalysis and water jet cavitation. The enhancement of photocatalysis by water jet cavitation could be due to the deagglomeration of catalyst particles as well as the better contact between the catalyst surfaces and the reactants. Venturi tube with smaller diameter and shorter length of throat tube favored the dye decolorization. The degradation efficiency was found to increase with decreasing initial concentration and pH. The presence of NO(3)(-) and SO(4)(2-) enhanced the degradation of RR2, while Cl(-), and especially HCO(3)(-) significantly reduced dye decolorization. The results of this study indicated that the coupled photocatalysis and water jet cavitation is effective in degrading dye in wastewater and provides a promising alternative for treatment of dye wastewater at a large scale. Copyright © 2010 Elsevier B.V. All rights reserved.

  3. Rock Breaking by Conical Pick Assisted with High Pressure Water Jet

    Directory of Open Access Journals (Sweden)

    Liu Songyong

    2014-03-01

    Full Text Available In the process of hard rock breaking, the conical pick bears great cutting force and wear, and the cutting efficiency is lower. Thus different combination ways of water jet and conical pick were proposed to solve this issue; for instance, water jet placed in the front of pick (JFP and water jet through the center of pick (JCP was researched by numerical simulation and experiments in this paper. First, the models of rock breaking were built based on SPH combined with finite element method. Then, the stress distribution of rock and the cut force of pick were analyzed when the rock broken by the conical pick assisted with the high pressure water jet. It indicates that the effect of the JCP on rock breaking is better than the JFP. At last, experiments about rock breaking with a conical pick and the JCP were conducted to verify the reliability of the simulation. It indicates that the rock breaking with the assistance of high pressure water jet cannot only reduce the pick force, but also increase the rock crushing volume.

  4. Dynamic effects of high-pressure pulsed water jet in low-permeability coal seams

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-hong; ZHOU Dong-ping; LU Yi-yu; KANG Yong; ZHAO Yu; WANG Xiao-chuan

    2009-01-01

    Mine gas extraction in China is difficult due to the characteristics such as mi-cro-porosity, low-permeability and high adsorption of coal seams. The pulsed mechanism of a high-pressure pulsed water jet was studied through theoretical analysis, experiment and field measurement. The results show that high-pressure pulsed water jet has three dynamic properties. What's more, the three dynamic effects can be found in low-perme-ability coal seams. A new pulsed water jet with 200-1 000 Hz oscillation frequency and peak pressure 2.5 times than average pressure was introduced. During bubble collapsing, sound vibration and instantaneous high pressures over 100 MPa enhanced the cutting ability of the high-pressure jet. Through high-pressure pulsed water jet drilling and slotting, the exposure area of coal bodies was greatly enlarged and pressure of the coal seams rapidly decreased. Therefore, the permeability of coal seams was improved and gas ab-sorption rate also decreased. Application results show that gas adsorption rate decreased by 30%-40% and the penetrability coefficient increased 100 times. This proves that high-pressure pulsed water is more efficient than other conventional methods.

  5. Numerical Simulation Study of Influence of Nozzle Entrance Diameter on Jet Performance of Pre-mixed Abrasive Water Jet

    Science.gov (United States)

    Guan, Jinfa; Deng, Songsheng; Jiao, Guangwei; Chen, Ming; Hua, Weixing

    Physical model of cone-cylinder nozzle was established. Based on the CFD software of FLUENT, the flow field about abrasive water jet in cone-cylinder nozzle was simulated by use of standard k-ɛ turbulent model, Lagrange Discrete Phase Model and SIMPLE algorithm. The simulation results show that axial velocity of abrasive particle is always smaller than axial velocity of abrasive particle and increases gradually with the increase of axial distance. Axial static pressure of water decreases gradually with the increase of axial distance. Axial velocity of abrasive particle at the exit of cone-cylinder nozzle decreases with the increase of nozzle entrance diameter. And axial static pressure of water at the entrance of cone-cylinder nozzle decreases with the increase of nozzle entrance diameter. 8mm is selected as an optimal nozzle entrance diameter.

  6. Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄故

    2001-01-01

    The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.

  7. Optimization of Abrasive Water Jet Cutting of Ductile Materials

    Institute of Scientific and Technical Information of China (English)

    Asif IQBAL; Naeem U DAR; Ghulam HUSSAIN

    2011-01-01

    Full factorial design of experiments was developed in order to investigate the effects of jet pressure, abrasive mixing rate, cutting feed, and plate thickness upon three response variables, surface finish of cutting wear zone, percentage proportion of striation free area, and maximum width of cut. The set of sixteen experiments was performed on each of the following two ductile materials: AISI 4340 (high strength low alloy steel, hardened to 49HRc) and Aluminum 2219. Analysis of Variance (ANOVA) was performed on experimental data in order to determine the significance of effects of different parameters on the performance measures. It was found that cutting feed and thickness were highly influential parameters, while abrasive mixing rate is influential upon surface roughness only. Strong interaction was found between jet pressure and workpiece material.Multi-criteria numerical optimization was performed in order to simultaneously maximize/minimize different combinations of performance measures.

  8. An investigation on co-axial water-jet assisted fiber laser cutting of metal sheets

    Science.gov (United States)

    Madhukar, Yuvraj K.; Mullick, Suvradip; Nath, Ashish K.

    2016-02-01

    Water assisted laser cutting has received significant attention in recent times with assurance of many advantages than conventional gas assisted laser cutting. A comparative study between co-axial water-jet and gas-jet assisted laser cutting of thin sheets of mild steel (MS) and titanium (Ti) by fiber laser is presented. Fiber laser (1.07 μm wavelength) was utilised because of its low absorption in water. The cut quality was evaluated in terms of average kerf, projected dross height, heat affected zone (HAZ) and cut surface roughness. It was observed that a broad range process parameter could produce consistent cut quality in MS. However, oxygen assisted cutting could produce better quality only with optimised parameters at high laser power and high cutting speed. In Ti cutting the water-jet assisted laser cutting performed better over the entire range of process parameters compared with gas assisted cutting. The specific energy, defined as the amount of laser energy required to remove unit volume of material was found more in case of water-jet assisted laser cutting process. It is mainly due to various losses associated with water assisted laser processing such as absorption of laser energy in water and scattering at the interaction zone.

  9. Validation of the THIRMAL-1 melt-water interaction code

    Energy Technology Data Exchange (ETDEWEB)

    Chu, C.C.; Sienicki, J.J.; Spencer, B.W. [Argonne National Lab., IL (United States)

    1995-09-01

    The THIRMAL-1 computer code has been used to calculate nonexplosive LWR melt-water interactions both in-vessel and ex-vessel. To support the application of the code and enhance its acceptability, THIRMAL-1 has been compared with available data from two of the ongoing FARO experiments at Ispra and two of the Corium Coolant Mixing (CCM) experiments performed at Argonne. THIRMAL-1 calculations for the FARO Scoping Test and Quenching Test 2 as well as the CCM-5 and -6 experiments were found to be in excellent agreement with the experiment results. This lends confidence to the modeling that has been incorporated in the code describing melt stream breakup due to the growth of both Kelvin-Helmholtz and large wave instabilities, the sizes of droplets formed, multiphase flow and heat transfer in the mixing zone surrounding and below the melt metallic phase. As part of the analysis of the FARO tests, a mechanistic model was developed to calculate the prefragmentation as it may have occurred when melt relocated from the release vessel to the water surface and the model was compared with the relevant data from FARO.

  10. Rock failure analysis by combined thermal weakening and water jet impact

    Science.gov (United States)

    Nayfeh, A. H.

    1976-01-01

    The influence of preheating on the initiation of fracture in rocks subjected to the impingement of a continuous water jet is studied. Preheating the rock is assumed to degrade its mechanical properties and strength in accordance with existing experimental data. The water jet is assumed to place a quasi-static loading on the surface of the rock. The loading is approximated by elementary functions which permit analytic computation of the induced stresses in a rock half-space. The resulting stresses are subsequently coupled with the Griffith criteria for tensile failure to estimate the change, due to heating, in the critical stagnation pressure and velocity of the water jet required to cause failure in the rock.

  11. Rock failure analysis by combined thermal weakening and water jet impact

    Science.gov (United States)

    Nayfeh, A. H.

    1976-01-01

    The influence of preheating on the initiation of fracture in rocks subjected to the impingement of a continuous water jet is studied. Preheating the rock is assumed to degrade its mechanical properties and strength in accordance with existing experimental data. The water jet is assumed to place a quasi-static loading on the surface of the rock. The loading is approximated by elementary functions which permit analytic computation of the induced stresses in a rock half-space. The resulting stresses are subsequently coupled with the Griffith criteria for tensile failure to estimate the change, due to heating, in the critical stagnation pressure and velocity of the water jet required to cause failure in the rock.

  12. Analysis and numerical simulation of dynamic effect on rock under high pressure water jet

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-hong; SI Hu; WANG Dan-dan

    2008-01-01

    Based on continuum mechanics and rock dynamics, analyzed the micro-structure damage of rock and the impulsive effect under high pressure water jet and developed the dynamic model. Further, on the assumption of that rock was homogeneous and isotropic, a computational model was established based on nonlinear finite element and Arbitrary Lagrangian-Eulerian(ALE) method. The dynamic effect impacted on rock under high pressure water jet was simulated by the dynamic contact method. The propagation of stress wave in rock was numerically simulated at different impacting velocity. The results show that the propagation velocity of stress wave is proportional to the impacting velocity of high pressure water jet. The faster the impacting velocity is, the quicker the comedown of stress wave.

  13. Energy Consumption in Comminution of Mica with Cavitation Abrasive Water Jet

    Institute of Scientific and Technical Information of China (English)

    GUO Chu-wen; DONG Lu

    2007-01-01

    We have studied the efficiency of energy consumption in the comminution of mica powder with cavitation abrasive water jet technology. The energy required to create new surfaces in the comminution of mica powder with cavitation abrasive water jet was calculated, in order to estimate its efficiency of energy consumption. The particle size distribution and the specific surface area were measured by applying a JEM-200CX transmission electron microscope and an Autosorb-1 automatic surface area analyzer. The study results show that the efficiency of energy consumed in creating new surface areas is as high as 2.92%, or 4.94% with the aid of cavitation in the comminution of mica powder. This efficiency will decrease with an increase in the number of comminutions. After three comminutions, the efficiencies will become 1.91% and 2.29% for comminution without cavitation and with cavitation, respectively. The abrasive water jet technology is an effective way for comminution of mica powder.

  14. 76 FR 16285 - Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To Update Water...

    Science.gov (United States)

    2011-03-23

    ... human health and aquatic life stream quality objectives (also called water quality criteria) for toxic... COMMISSION 18 CFR Part 410 Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To Update Water Quality Criteria for Toxic Pollutants in the Delaware Estuary and Extend These Criteria to...

  15. THREE-DIMENSIONAL NUMERICAL SIMULATION OF MULTIPLE JETS IN SHALLOW FLOWING RECEIVING WATERS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper is concerned with the simulation of the mixing mechanism of submerged multiport diffusers used to discharge heated water from thermal-electric power plants and households into shallow receiving waters. The three-dimensional turbulence model and hybrid finite analytic method are used to predict the behavior of near field for multiport buoyant jets in rivers. The predicted temperature dilution and velocity prove good by comparison with available laboratory measurements. An empirical formula for temperature dilution and velocity in near field for this kind of flow is given. The effect of parameters on the dilution behavior of multiple jets are also discussed.

  16. Study on Turbulent Behavior of Water Jet in Supersonic Steam Injector

    Science.gov (United States)

    Fukuichi, Akira; Abe, Yutaka; Fujiwara, Akiko; Kawamoto, Yujiro; Iwaki, Chikako; Narabayashi, Tadashi; Mori, Michitsugu; Ohmori, Shuichi

    One of the most interesting devices for light water reactor systems aimed at simplified system, improvement of safety and reliability is a supersonic steam injector. Supersonic steam injector is a passive jet pump without rotating machine and high efficient heat exchanger because of direct contact condensation between supersonic steam and a subcooled water jet. It is considered that flow behavior in the supersonic steam injector is related to complicated turbulent flow with large shear stress induced by velocity difference between steam and water and direct contact condensation. However, studies about turbulent flow under large shear stress with direct contact condensation are not enough. Especially, mechanisms of momentum and heat transfer are not clarified in detail. Objective of the present study is to investigate turbulent behaviors of a water jet and interface that play an important role in heat transfer and momentum transfer. Radial distribution of streamwise velocity and fluctuation of total pressure are measured by a pitot measurement. Visual measurement of the turbulent water jet is conducted by a high speed camera in order to identify location of unstable interface and its behavior. It is found that streamwise velocity increases as it approaches downstream of the mixing nozzle. Fluctuation of total pressure is large at water-steam mixture region. It is confirmed that waves propagated on the interface. And its velocity is obtained.

  17. Nozzle optimization for water jet propulsion with a positive displacement pump

    Science.gov (United States)

    Yang, You-sheng; Xie, Ying-chun; Nie, Song-lin

    2014-06-01

    In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.

  18. Nozzle Optimization for Water Jet Propulsion with A Positive Displacement Pump

    Institute of Scientific and Technical Information of China (English)

    杨友胜; 谢迎春; 聂松林

    2014-01-01

    In the water jet propulsion system with a positive displacement (PD) pump, the nozzle, which converts pressure energy into kinetic energy, is one of the key parts exerting great influence on the reactive thrust and the efficiency of the system due to its high working pressure and easily occurring cavitation characteristics. Based on the previous studies of the energy loss and the pressure distribution of different nozzles, a model of water jet reactive thrust, which fully takes the energy loss and the nozzle parameters into consideration, is developed to optimize the nozzle design. Experiments and simulations are carried out to investigate the reactive thrust and the conversion efficiency of cylindrical nozzles, conical nozzles and optimized nozzles. The results show that the optimized nozzles have the largest reactive thrust and the highest energy conversion efficiency under the same inlet conditions. The related methods and conclusions are extended to the study of other applications of the water jet, such as water jet cutting, water mist fire suppression, water injection molding.

  19. Effect of Stand-Off Distance on Impact Pressure of High Speed Water Jets

    Science.gov (United States)

    Sittiwong, Wuttichai; Seehanam, Wirapan; Pianthong, Kulachate; Matthujak, Anirut

    2010-06-01

    High speed liquid jets may be applied to jet cutting, drilling and cleaning. Recently, in the automotive industries, the spray injection pressure becomes higher and higher to enhance the fuel mixing for the improved combustion efficiency. However, the ultra high injection pressure may cause the damage to the nozzle and also the combustion chamber. In the medical application, the high speed liquid injection might be applied for the drug delivery through the skin where the needle is not required anymore. From the above mentioned application, the investigation on the impact pressure of the high speed liquid jet relative to the stand-off distant is significant. The high speed liquid jets are generated by the projectile impact driven method. The high speed projectile is launched by the horizontal single stage powder gun. The experimental study focuses on the stand-off between 1.5 cm to 6.0 cm, while the nozzle contains approximately 1.5cm3 of water in its cavity. The nozzle conical angles are 30° and 60° with the orifice diameter of 0.7 mm. The jet velocities are measured by laser beam interruptions method. The target material is the Polymethyl Methacrylate (PMMA) which the impact pressure is measured by using a piezoelectric Polyvinylidene Fluoride (PVDF) film. From the experiments, the maximum water jet velocity of 2290 m/s can be obtained from the 30° conical angle nozzle. The maximum impact pressures of nozzle conical angle of 30° and 60° are 3.4 GPa and 2.6 GPa respectively, at stand-off distance 3 cm. However, at the stand-off distance more than 3 cm, the impact pressure significantly decreases, because of aerodynamic drag, jets core break-up, and atomization of the water.

  20. Simulation of Containment Jet Flows Including Condensation

    OpenAIRE

    HEITSCH Matthias; Baraldi, Daniele; WILKENING Heinz

    2009-01-01

    The validation of a CFD code for light-water reactor containment applications requires among others the presence of steam in the different flow types like jets or buoyant plumes and leads to the need to simulate condensation phenomena. In this context the paper addresses the simulation of two ¿HYJET¿ experiments from the former Battelle Model Containment by the CFD code CFX. These experiments involve jet releases into the multicompartment geometry of the test facility accompani...

  1. 78 FR 47241 - Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To Revise the...

    Science.gov (United States)

    2013-08-05

    ... COMMISSION 18 CFR Part 410 Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To Revise the Human Health Water Quality Criteria for PCBs in Zones 2 Through 6 of the Delaware Estuary and... comments on proposed amendments to the Commission's Water Quality Regulations, Water Code and Comprehensive...

  2. 78 FR 58985 - Proposed Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To Update...

    Science.gov (United States)

    2013-09-25

    ... COMMISSION 18 CFR Part 410 Proposed Amendments to the Water Quality Regulations, Water Code and Comprehensive Plan To Update Water Quality Criteria for pH AGENCY: Delaware River Basin Commission. ACTION: Proposed... on proposed amendments to the Commission's Water Quality Regulations, Water Code and...

  3. Do water fountain jets really indicate the onset of the morphological metamorphosis of circumstellar envelopes?

    Science.gov (United States)

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Hsia, Chih-Hao; Imai, Hiroshi

    2017-03-01

    Small-scale bipolar jets with short dynamical ages from 'water-fountain' (WF) sources are regarded as an indication of the onset of circumstellar envelope morphological metamorphosis of intermediate-mass stars. Such a process usually happens at the end of the asymptotic giant branch (AGB) phase. However, recent studies found that WFs could be AGB stars or even early planetary nebulae. This fact prompted the idea that WFs may not necessarily be objects at the beginning of the morphological transition process. In the present work, we show that WFs could have different envelope morphologies by studying their spectral energy distribution profiles. Some WFs have spherical envelopes that resemble usual AGB stars, while others have aspherical envelopes, which are more common to post-AGB stars. The results imply that WFs may not represent the earliest stage of morphological metamorphosis. We argue further that the dynamical age of a WF jet, which can be calculated from maser proper motions, may not be the real age of the jet. The dynamical age cannot be used to justify the moment when the envelope begins to become aspherical, nor to tell the concrete evolutionary status of the object. A WF jet could be the innermost part of a larger well-developed jet, which is not necessarily a young jet.

  4. Preliminary study on occurrence of composite material delamination processed by abrasive water jet cutting

    Directory of Open Access Journals (Sweden)

    Popan Ioan Alexandru

    2017-01-01

    Full Text Available The paper presents a preliminary experimental study on processing composite materials (CFRP using abrasive water jet cutting (AWJC process, analysing the possibilities of occurrence of material delamination. AWJC is a proper solution for cutting CFRP because of reduced interface temperature, high flexibility, low mechanical loading and reduced cutting forces. Cutting CFRP using AWJC involves several challenges like material delamination due to the high velocity impact of the jet. To understand the delamination, three experimental tests were made: in the first test the cutting and the drilling was made with high water pressure (350 MPa, in the second test the cutting was made with high water pressure and for drilling was used low water pressure (200 MPa and in last test a pre-drilled hole was used. Within those experiments was observed the CFRP delamination appears just during the drilling, not during the cutting. By decreasing the water jet pressure, the jet energy is decreased and in this way the delamination decrease.

  5. Role of water and discharge mode on modulating properties in an atmospheric air MHCD jet

    Science.gov (United States)

    Liu, Kun; Wang, Chenying; Lei, Juzhang; Hu, Huimin; Zheng, Peichao; He, Wei

    2016-04-01

    A portable micro hollow cathode discharge (MHCD) device was designed in this paper to generate water-air plasma jet. The results showed that MHCD jet pattern was changed from self-pulsing discharge mode to DC mode with the increasing of voltage, and the critical voltage value of discharge mode increased with the rise of gas flow. In order to study the influences of discharge mode and water content on MHCD jet, the electrical characteristics and radicals were all measured in different conditions. We found that the length of jet decreased and temperature increased with raising water-air ratio, and during self-pulsing discharge mode, •OH content was extremely low because of the low energy of electron, but level of NO was raised with gradually increasing applied voltage. In DC mode, the results showed there was least NO content, on the other hand •OH content increased with rise of voltage and water-air ratio. O existed in both discharge modes and the effect of water content on the O production was complex. Contribution to the Topical Issue "Recent Breakthroughs in Microplasma Science and Technology", edited by Kurt Becker, Jose Lopez, David Staack, Klaus-Dieter Weltmann and Wei Dong Zhu.

  6. NUMERICAL STUDY ON THE STABILITY AND MIXING OF VERTICAL ROUNE BUOYANT JET IN SHALLOW WATER

    Institute of Scientific and Technical Information of China (English)

    曾玉红; 槐文信

    2005-01-01

    The k-epsilon model was applied to establish the mathematical model of vertical round buoyant jet discharging into confined depth, and it was solved using the Hybrid Finite Analytic Method ( HFAM ). The numerical predictions demonstrate two generic flow patterns for different jet discharge and environmental parameters: ( i ) a stable buoyant flow discharge with the mixed fluid leaving the near-field warm in a surface warm water layer;( ii ) an unstable buoyant flow discharge with recirculation and re-entrainment of warm water in the near field. Furthermore, the mixing characters of vertical round buoyant jet were numerically predicted. Both the stability criterion and numerical predictions of bulk dilutions are in excellent agreement with Lee and Jirka ' s experiments and theory.

  7. Stratospheric areal distribution of water vapor burden and the jet stream

    Science.gov (United States)

    Kuhn, P. M.; Magaziner, E.; Stearns, L. P.

    1976-01-01

    Radiometrically inferred areal observations of the atmospheric water vapor burden have been made in the 270 to 520 per cm spectral band over western U.S. and the extreme eastern Pacific from the NASA C-141 Kuiper Airborne Observatory. Before this, very few observations from the upper troposphere and lower stratosphere over such a broad area have been made. A total of 30,600 individual observations from eight separate synoptic situations involving eight jet maxima were computer-averaged over 2-deg latitude x 2-deg longitude boxes and related to the polar continental jet. Mean water vapor burdens ranged from 0.00046 to 0.00143 g per sq cm at 13.4 km with a striking peak just north of the jet wind maximum over a region of strong upward vertical motion.

  8. Numerical simulation on submerged gas jet scouring pit morphology in impingement water bath dust removers

    Institute of Scientific and Technical Information of China (English)

    GAO Huijie; WU Xuan; ZHAO Yuxiang; WU Wenfei; LI Baowei

    2014-01-01

    The VOF interface tracking method was adopted to simulate the two-dimensional submerged gas jet scouring pit morphology in an impingement water bath dust remover.The interaction of gas/liquid two-phase was obtained by force balance and momentum exchange.On the self-designed impingement water bath dust remover test bench,the submerged gas jet flushing with different gas velocities was simulated. The results show that,the gas inlet velocity is one of the main factors affecting the submerged gas jet scou-ring pit characteristics.The unique nature of gas/liquid two-phase determines their unique way of move-ment,thus affects the morphological character of the scouring pit in the expansion lag phase.Within the study range,the characteristic radius and impact depth of the scouring pit increases with the gas velocity, and so are their growth rates.

  9. A Proposal to Build a Laboratory Blast Overpressure Test Simulator; Subtitle: The Development of a Water Jet Impactor

    Science.gov (United States)

    1982-07-01

    BLAST oVtiRaPSSURE TLST SIMULATOR; Subtitles The Oevelopment of a Water Jet !mpactor Final Report (byo0 Jams .- Y. Yu Udvard J. Veael July 1952...suggested that an alternative approach was re- qui red. Ono of the plausible approaches was to use pulses of high velocity water jets to hit the

  10. Cooling Effect of Water Injection on a High-Temperature Supersonic Jet

    Directory of Open Access Journals (Sweden)

    Jing Li

    2015-11-01

    Full Text Available The high temperature and high pressure supersonic jet is one of the key problems in the design of solid rocket motors. To reduce the jet temperature and noise, cooling water is typically injected into the exhaust plume. Numerical simulations for the gas-liquid multiphase flow field with mixture multiphase model were developed and a series of experiments were carried out. By introducing the energy source terms caused by the vaporization of liquid water into the energy equation, a coupling solution was developed to calculate the multiphase flow field. The temperature data predictions agreed well with the experimental results. When water was injected into the plume, the high temperature core region area was reduced, and the temperature on the head face was much lower than that without water. The relationship between the reduction of temperature on the bottom plate and the momentum ratio is developed, which can be used to predict the cooling effect of water injection in many cases.

  11. A laser-induced pulsed water jet for layer-selective submucosal dissection of the esophagus.

    Science.gov (United States)

    Nakano, T; Sato, C; Yamada, M; Nakagawa, A; Yamamoto, H; Fujishima, F; Tominaga, T; Satomi, S; Ohuchi, N

    2016-10-01

    Background and aims: Conventional water jet devices have been used for injecting fluid to lift up lesions during endoscopic submucosal dissection or endoscopic mucosal resection procedures. However, these devices cannot dissect the submucosal layer effectively. Here we aim to elucidate the dissection capability of a laser-induced pulsed water jet and to clarify the mechanism of dissection with layer selectivity. Materials (Subjects) and methods: Pulsed water jets were ejected from a stainless nozzle by accelerating saline using the energy of a pulsed holmium: yttrium-aluminum-garnet laser. The impact force (strength) of the jet was evaluated using a force meter. Injection of the pulsed jet into the submucosal layer was documented by high-speed imaging. The physical properties of the swine esophagus were evaluated by measuring the breaking strength. Submucosal dissection of the swine esophagus was performed and the resection bed was evaluated histologically. Results: Submucosal dissection of the esophagus was accomplished at an impact force of 1.11-1.47 N/pulse (laser energy: 1.1-1.5 J/pulse; standoff distance: 60 mm). Histological specimens showed clear dissection at the submucosal layer without thermal injury. The mean static breaking strength of the submucosa (0.11 ± 0.04 MPa) was significantly lower than that of the mucosa (1.32 ± 0.18 MPa), and propria muscle (1.45 ± 0.16 MPa). Conclusions: The pulsed water jet device showed potential for achieving selective submucosal dissection. It could achieve mucosal, submucosal, and muscle layer selectivity owing to the varied breaking strengths.

  12. Full factorial DOE to determine the influence of the process parameters in cleaning water jets used in sewer cleaning

    Directory of Open Access Journals (Sweden)

    Medan Nicolae

    2017-01-01

    Full Text Available Industrial cleaning is a classic application of water jets technology. In the late 1950s, when reliable high pressure pumps were built, the usage of water jets spread widely in the field of pipes and sewerage cleaning. In our particular case, water jets using pressure between 100 and 200 bars are being used. The operational behaviour of these systems is dependent on the process parameters, which can vary, causing variations in the impact force. The experiment consists in the research method used in the study of the impact forces that occur in the sewerage cleaning head system. To determine the influence process parameters have on impact forces, the full factorial method was used. In order to measure the impact forces between the water jet and a flat and rigid surface, a stand was designed and built for generating pressure water jets, as well as a device to measure the impact forces.

  13. Comparing different Ultraviolet Imaging Spectrograph (UVIS) occultation observations using modeling of water vapor jets

    Science.gov (United States)

    Portyankina, Ganna; Esposito, Larry W.; Hansen, Candice; Aye, Klaus-Michael

    2016-10-01

    Motivation: On March 11, 2016 the Cassini UVIS observed its 6th star occultation by Enceladus' plume. This observation was aimed to determine variability in the total gas flux from the Enceladus' southern polar region. The analysis of the received data suggests that the total gas flux is moderately increased comparing to the average gas flux observed by UVIS from 2005 to 2011 [1]. However, UVIS detected variability in individual jets. In particular, Baghdad 1 is more collimated in 2016 than in 2005, meaning its gas escapes at higher velocity.Model and fits: We use 3D DSMC model for water vapor jets to compare different UVIS occultation observations from 2005 to 2016. The model traces test articles from jets' sources [2] into space and results in coordinates and velocities for a set of test particles. We convert particle positions into the particle number density and integrate along UVIS line of sight (LoS) for each time step of the UVIS observation using precise observational geometry derived from SPICE [3]. We integrate all jets that are crossed by the LoS and perform constrained least-squares fit of resulting modeled opacities to the observed data to solved for relative strengths of jets. The geometry of each occultation is specific, for example, during solar occultation in 2010 UVIS LoS was almost parallel to tiger stripes, which made it possible to distinguish jets venting from different tiger stripes. In 2011 Eps Orionis occultation LoS was perpendicular to tiger stripes and thus many of the jets were geometrically overlapping. Solar occultation provided us with the largest inventory of active jets - our model fit detects at least 43 non-zero jet contributions. Stellar occultations generally have lower temporal resolution and observe only a sub-set of these jets: 2011 Eps Orionis needs minimum 25 non-zero jets to fit UVIS data. We will discuss different occultations and models fits, including the most recent Epsilon Orionis occultation of 2016.[1] Hansen et al

  14. Fast Ion Effects on Fishbones and n=1 Kinks in JET Simulated by a Non-perturbative NOVA-KN Code

    Energy Technology Data Exchange (ETDEWEB)

    N.N. Gorelenkov; C.Z. Cheng; V.G. Kiptily; M.J. Mantsinen; S.E. Sharapov; the JET-EFDA Contributors

    2004-10-28

    New global non-perturbative hybrid code, NOVA-KN, and simulations of resonant type modes in JET [Joint European Torus] plasmas driven by energetic H-minority ions are presented. The NOVA-KN code employs the ideal-MHD description for the background plasma and treats non-perturbatively the fast particle kinetic response, which includes the fast ion finite orbit width (FOW) effect. In particular, the n = 1 fishbone mode, which is in precession drift resonance with fast ions, is studied. The NOVA-KN code is applied to model an n = 1 (f = 50-80kHz) MHD activity observed recently in JET low density plasma discharges with high fast ion (H-minority) energy content generated during the ion cyclotron resonance heating (ICRH). This n = 1 MHD activity is interpreted as the instability of the n = 1 precession drift frequency fishbone modes.

  15. Small-Scale Morphological Features on a Solid Surface Processed by High-Pressure Abrasive Water Jet.

    Science.gov (United States)

    Kang, Can; Liu, Haixia

    2013-08-14

    Being subjected to a high-pressure abrasive water jet, solid samples will experience an essential variation of both internal stress and physical characteristics, which is closely associated with the kinetic energy attached to the abrasive particles involved in the jet stream. Here, experiments were performed, with particular emphasis being placed on the kinetic energy attenuation and turbulent features in the jet stream. At jet pressure of 260 MPa, mean velocity and root-mean-square (RMS) velocity on two jet-stream sections were acquired by utilizing the phase Doppler anemometry (PDA) technique. A jet-cutting experiment was then carried out with Al-Mg alloy samples being cut by an abrasive water jet. Morphological features and roughness on the cut surface were quantitatively examined through scanning electron microscopy (SEM) and optical profiling techniques. The results indicate that the high-pressure water jet is characterized by remarkably high mean flow velocities and distinct velocity fluctuations. Those irregular pits and grooves on the cut surfaces indicate both the energy attenuation and the development of radial velocity components in the jet stream. When the sample is positioned with different distances from the nozzle outlet, the obtained quantitative surface roughness varies accordingly. A descriptive model highlighting the behaviors of abrasive particles in jet-cutting process is established in light of the experimental results and correlation analysis.

  16. Small-Scale Morphological Features on a Solid Surface Processed by High-Pressure Abrasive Water Jet

    Directory of Open Access Journals (Sweden)

    Can Kang

    2013-08-01

    Full Text Available Being subjected to a high-pressure abrasive water jet, solid samples will experience an essential variation of both internal stress and physical characteristics, which is closely associated with the kinetic energy attached to the abrasive particles involved in the jet stream. Here, experiments were performed, with particular emphasis being placed on the kinetic energy attenuation and turbulent features in the jet stream. At jet pressure of 260 MPa, mean velocity and root-mean-square (RMS velocity on two jet-stream sections were acquired by utilizing the phase Doppler anemometry (PDA technique. A jet-cutting experiment was then carried out with Al-Mg alloy samples being cut by an abrasive water jet. Morphological features and roughness on the cut surface were quantitatively examined through scanning electron microscopy (SEM and optical profiling techniques. The results indicate that the high-pressure water jet is characterized by remarkably high mean flow velocities and distinct velocity fluctuations. Those irregular pits and grooves on the cut surfaces indicate both the energy attenuation and the development of radial velocity components in the jet stream. When the sample is positioned with different distances from the nozzle outlet, the obtained quantitative surface roughness varies accordingly. A descriptive model highlighting the behaviors of abrasive particles in jet-cutting process is established in light of the experimental results and correlation analysis.

  17. Investigation on Water Jet Treated Polyester/cotton Blended Cambric

    Institute of Scientific and Technical Information of China (English)

    黄故

    2004-01-01

    Analytical examination was made to ascertain the effect of the high pressure water flow on the fabric properties.Polyester/cotton blended cambric was spurted by high pressure water flow. Fabric properties such as handle,thickness, tensile strength , stiffness and air permeability after the water treatment were investigated.

  18. Overview on Water Jet Technology%水射流技术综述

    Institute of Scientific and Technical Information of China (English)

    陶欢; 雷玉勇; 杨涵; 张丽; 陈玄

    2015-01-01

    Water Jet technology is a new technology that developed rapidly in recent years which using the booster pump to pressurized water into a state of high speed jet to realize cleaning, cutting, crushing and so on. Compared with traditional manufacture method, water jet technology has many advantages such as high machining accuracy, without thermal deformation, saving materials, environmentally friendly and so on. Water jet technology has a broad development prospects. This paper introduces its working theory, advantages and problems, applications and its development tendency.%近年来水射流技术作为一项新技术得到迅速发展,采用增压泵将水加压,形成高速射流,完成材料的清洗、切割、破碎等操作。相比传统方式,水射流技术具有加工精度高、工件无热变形、材料损耗少、环境友好等加工优势,具有广阔的发展前景。本文介绍了水射流技术的工作原理、优缺点、应用以及发展趋势。

  19. Residual Stress Improved by Water Jet Peening for A Quenched Gear

    Institute of Scientific and Technical Information of China (English)

    Dong-Ying Ju; H. Tsuda; Vincent Ji; T. Uchiyama; R. Oba

    2004-01-01

    In this paper, a running cost is cheap from the thing used for harmless peening treatment to the environment,health which an influence is rare in toward processing material like heat being only water fundamentally, and economical,and the characteristics is hard to get are given. There is some research about the residual stress improvement by water-jet peening during the high-speed water. In this study, a big bubble cloud ceremony water-jet peening which dissolves the problem of the form of the applicable thing by exposing the whole of the applicable thing in the big bubble cloud as the way of dealing with peening efficiently in a short time is proposed by this research. Moreover, the uniform compression residual stress is added around the surface of the processing side, and connected with the remarkable improvement of the fatigue strength of the part. Furthermore, and safety processing is very possible, and it thinks about the thing which has possible high practical use, and writers to get rid of the problems of the way of processing it with peening until now. Water-jet peening was given by this research during high-speed water with big bubble cloud-type water toward tooth gear manufactured by SCr420H3V2 to open the effect of water-jet peening during the high-speed water. A change was measured at the time as the sutra of the residual stress on the surface of the test settlement by the X-ray method, and the validity of this law was verified.

  20. Computational Fluid Dynamics Analysis of Nozzle in Abrasive Water Jet Machining

    Science.gov (United States)

    Venugopal, S.; Chandresekaran, M.; Muthuraman, V.; Sathish, S.

    2017-03-01

    Abrasive water jet cutting is one of the most recently developed non-traditional manufacturing technologies. The general nature of flow through the machining, results in rapid wear of the nozzle which decrease the cutting performance. It is well known that the inlet pressure of the abrasive water suspension has main effect on the erosion characteristics of the inner surface of the nozzle. The objective of the project is to analyze the effect of inlet pressure on wall shear and exit kinetic energy. The analysis would be carried out by varying the inlet pressure of the nozzle, so as to obtain optimized process parameters for minimum nozzle wear. The two phase flow analysis would be carried by using computational fluid dynamics tool CFX. The availability of minimized process parameters such as of abrasive water jet machining (AWJM) is limited to water and experimental test can be cost prohibitive.

  1. Ossification of the frontal sinus in juvenile minipigs following water jet application.

    Science.gov (United States)

    Lenz, Jan-Hendrik; Henkel, Kai-Olaf; Schmidt, Wolfgang; Fulda, Gerhard; Hingst, Volker; Gundlach, Karsten K H

    2006-03-01

    Obliteration of the frontal sinus is a generally accepted management for patients with severe craniofacial trauma in whom the sinus cannot be repaired or adequately drained. Effective obliteration requires complete removal of mucosa, sufficient filling of the sinus cavity as well as effective occlusion of the nasofrontal duct. The use of various filling materials for sinus obliteration has been described and include autologous fat, bone, muscle and lyophilized cartilage. In order to appreciate the advantages of the water-jet scalpel an animal study in 10 juvenile (4 months old) and 10 adult (18 months) minipigs was performed. In 5 juvenile and 5 adult animals the frontal sinus mucosa was removed using the water jet, while in the others bone curettes were used. No occlusion of the frontonasal duct was carried out and no filling material was implanted. All animals were followed-up for 40 days. After sacrifice, radiological, histological and computerized histomorphometrical examinations were carried out. Removal of the mucosa from the sinus was simplified when using the water jet. Previous studies have shown that the selected tissue structures were less traumatized when compared with conventional surgical techniques. In young animals (only) and exclusively following the use of a water-jet scalpel osseous occlusion of the frontal sinus was found at follow-up. Histomorphometric findings revealed a significant increase of bone formation in the frontal sinus area of these animals. Based on these experimental results in a small series of juvenile minipigs the water-jet technique is a faster and less traumatic technique (less blood loss) for osteoplastic surgery of the frontal sinus. Further long-term studies are needed to evaluate the possibilities for applying this technique in post-traumatic craniofacial surgery in man.

  2. Selective fluid cushion in the submucosal layer by water jet: advantage for endoscopic mucosal resection.

    Science.gov (United States)

    Kaehler, G F B A; Sold, M G; Fischer, K; Post, S; Enderle, M

    2007-01-01

    Numerous new techniques have recently been reported and described for the endoscopic mucosal resection of large superficial lesions of the gastrointestinal tract. We present here for the first time the application of a water jet dissector for mucosa elevation. In an ex vivo study, the effectiveness of a water jet dissector (Helix Hydro-Jet) placed directly on the stomach walls of 8 pigs was examined to create a mucosal elevation. After having determined optimal pressures, angle of application, and application times, 13 submucosal fluid cushions were produced in different areas of the stomach walls of 8 pigs in vivo, and the sizes of the resulting submucosal cushions were measured. Using pressures between 30 and 70 bar, it was routinely possible to create submucosal fluid cushions in the stomach wall ex vivo as well as in vivo. Histological examination showed a selective edema in the submucosa without damage to the deeper mucosal layers of the gastric wall. The capacity of a targeted high-pressure water jet to penetrate the mucosa and selectively create a fluid cushion in the submucosa facilitates endoscopic resection of the mucosa. This new method could contribute to ameliorate the endoscopic treatment of mucosal tumors which previously could not be resected endoscopically due to their size, extent, or location. Copyright 2007 S. Karger AG, Basel.

  3. Preliminary study of sand jets in water-capped artificial and real MFT

    Energy Technology Data Exchange (ETDEWEB)

    Cai, J.; Zhu, D.; Rajaratnam, N. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

    2008-07-01

    A preliminary study of sand jets in water-capped artificial and real MFT was presented. Background information on oil sands tailing reclamation including water capping and sand capping were first discussed, followed by background information to the study, including non-Newtonian fluids and laponite clay, the artificial clay used mainly in small amounts as a rheology modifier in industrial fluids and materials. Although laponite clay is insoluble in water, it hydrates to make a clear and colourless colloidal, which is thixotropic and also behaves as a Bingham plastic fluid. The benefit of using gels made from laponite is the ability to see through to observe the physical processes in it. The objectives of the study were to examine the dynamics of sand jets in water-capped laponite gel and real MFT; improve the understanding of physical processes related to MFT and sand/slurry operations in tailings ponds; and find potential applications in recycling processed water and decommissioning of tailings ponds. It was concluded that it is much more difficult for jets to penetrate water-capped MFT due to larger yield stress in MFT. Future studies will focus on density correction, viscosity adjustment, and sensitivity analysis. tabs., figs.

  4. Computational fluid dynamics (CFD) in the design of a water-jet-drive system

    Science.gov (United States)

    Garcia, Roberto

    1994-01-01

    NASA/Marshall Space Flight Center (MSFC) has an ongoing effort to transfer to industry the technologies developed at MSFC for rocket propulsion systems. The Technology Utilization (TU) Office at MSFC promotes these efforts and accepts requests for assistance from industry. One such solicitation involves a request from North American Marine Jet, Inc. (NAMJ) for assistance in the design of a water-jet-drive system to fill a gap in NAMJ's product line. NAMJ provided MSFC with a baseline axial flow impeller design as well as the relevant working parameters (rpm, flow rate, etc.). This baseline design was analyzed using CFD, and significant deficiencies identified. Four additional analyses were performed involving MSFC changes to the geometric and operational parameters of the baseline case. Subsequently, the impeller was redesigned by NAMJ and analyzed by MSFC. This new configuration performs significantly better than the baseline design. Similar cooperative activities are planned for the design of the jet-drive inlet.

  5. Effect of plasma jet diameter on the efficiency of reactive oxygen and nitrogen species generation in water

    Science.gov (United States)

    Oh, Jun-Seok; Kakuta, Maito; Furuta, Hiroshi; Akatsuka, Hiroshi; Hatta, Akimitsu

    2016-06-01

    The plasma jet generation of reactive oxygen and nitrogen species (RONS) in solution is important in biology, medicine, and disinfection. Studies using a wide variety of plasma jet devices have been carried out for this purpose, making it difficult to compare the performance between devices. In this study, we compared the efficiency of RONS generation in deionized (DI) water between 3.7-mm- and 800-µm-sized helium (He) plasma jets (hereafter mm-jet and µm-jet, respectively) at different treatment distances and times. The efficiency of RONS generation was determined by considering the total amount of RONS generated in DI water with respect to the input energy and gas consumption. We found that the mm-jet generated 20% more RONS in the DI water than the µm-jet at the optimized distance. However, when the input power and He gas consumption were taken into account, we discovered that the µm-jet was 5 times more efficient in generating RONS in the DI water. Under the parameters investigated in this study, the concentration of RONS continued to increase as a function of treatment time (up to 30 min). However treatment distance had a marked effect on the efficiency of RONS generation: treatment distances of 25 and 30 mm were optimal for the mm-jet and µm-jet, respectively. Our method of comparing the efficiency of RONS generation in solution between plasma jets could be used as a reference protocol for the development of efficient plasma jet sources for use in medicine, biology, and agriculture.

  6. Features of deformation of metal body surfaces under impact of a water jet

    Science.gov (United States)

    Aganin, A. A.; Khismatullina, N. A.

    2016-01-01

    The paper presents a mathematical model and computational results on dynamics of a perfect elastic-plastic body under the load arising during impact of a high-velocity liquid jet with the hemispherical end. The body is simulated by the isotropic linearly-elastic semi-space, its plastic state is described by the von Mises condition. The dependence of features of the body surface deformation on the body material is studied. The problem is considered in the axisymmetric statement. The axis of symmetry is that of the jet. The loaded domain is a circle with its radius rapidly growing from zero to the jet radius. The pressure in the loaded domain is non-uniform both in time and space. Three metal alloys (aluminium, copper-nickel and steel) are considered as the body material. The loading of the body surface in all the cases corresponds to the impact of a water jet with the radius 100 pm and the velocity 300 m/s. It has been shown that under such impact a nanometer pit arises on the body surface at the center of the domain of the jet action. The profile of the pit and its maximal depth depend on the body material.

  7. Impact jetting of water ice, with application to the accretion of icy planetesimals and Pluto

    Science.gov (United States)

    Mckinnon, William B.

    1989-01-01

    Jetting can occur during oblique impacts of water-ice bodies at relative velocities as low as 500 m/sec, because of the low Hugoniot elastic limit and high compressibility of ice compared to rock. In jetted ice, incipient melting, complete melting, and incipient vaporization occur, upon release to low pressure, at impact velocities of 1.3, 2.0, and 2.7 km/sec, respectively, much less than the 3.4, 4.4, and 5.3 km/sec, required in head-on collisions. Uncertainties in the shock equation-of-state may allow complete melting during jetting of relative velocities as low as 1.2 km/sec. Because jet speeds exceed impact speeds during the accretion of icy bodies greater than a few 100 km in radius, there may be a significant loss of icy material. Thus, jetting during a Charon-forming collision (and not vaporization) may account for Pluto-Charon's relatively large rock/ice ratio, should the C/O ratio of the solar nebula turn out to be too low to sufficiently raise the rock/ice ratio of outer solar nebula condensates by formation of noncondensable CO.

  8. Numerical Simulation of Water Jet Flow Using Diffusion Flux Mixture Model

    Directory of Open Access Journals (Sweden)

    Zhi Shang

    2014-01-01

    Full Text Available A multidimensional diffusion flux mixture model was developed to simulate water jet two-phase flows. Through the modification of the gravity using the gradients of the mixture velocity, the centrifugal force on the water droplets was able to be considered. The slip velocities between the continuous phase (gas and the dispersed phase (water droplets were able to be calculated through multidimensional diffusion flux velocities based on the modified multidimensional drift flux model. Through the numerical simulations, comparing with the experiments and the simulations of traditional algebraic slip mixture model on the water mist spray, the model was validated.

  9. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    Science.gov (United States)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2011-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  10. Reduction of Altitude Diffuser Jet Noise Using Water Injection

    Science.gov (United States)

    Allgood, Daniel C.; Saunders, Grady P.; Langford, Lester A.

    2014-01-01

    A feasibility study on the effects of injecting water into the exhaust plume of an altitude rocket diffuser for the purpose of reducing the far-field acoustic noise has been performed. Water injection design parameters such as axial placement, angle of injection, diameter of injectors, and mass flow rate of water have been systematically varied during the operation of a subscale altitude test facility. The changes in acoustic far-field noise were measured with an array of free-field microphones in order to quantify the effects of the water injection on overall sound pressure level spectra and directivity. The results showed significant reductions in noise levels were possible with optimum conditions corresponding to water injection at or just upstream of the exit plane of the diffuser. Increasing the angle and mass flow rate of water injection also showed improvements in noise reduction. However, a limit on the maximum water flow rate existed as too large of flow rate could result in un-starting the supersonic diffuser.

  11. A review on nozzle wear in abrasive water jet machining application

    Science.gov (United States)

    Syazwani, H.; Mebrahitom, G.; Azmir, A.

    2016-02-01

    This paper discusses a review on nozzle wear in abrasive water jet machining application. Wear of the nozzle becomes a major problem since it may affect the water jet machining performance. Design, materials, and life of the nozzle give significance effect to the nozzle wear. There are various parameters that may influence the wear rate of the nozzle such as nozzle length, nozzle inlet angle, nozzle diameter, orifice diameter, abrasive flow rate and water pressure. The wear rate of the nozzle can be minimized by controlling these parameters. The mechanism of wear in the nozzle is similar to other traditional machining processes which uses a cutting tool. The high pressure of the water and hard abrasive particles may erode the nozzle wall. A new nozzle using a tungsten carbide-based material has been developed to reduce the wear rate and improve the nozzle life. Apart from that, prevention of the nozzle wear has been achieved using porous lubricated nozzle. This paper presents a comprehensive review about the wear of abrasive water jet nozzle.

  12. Computational Fluid Dynamic Simulation of Flow in Abrasive Water Jet Machining

    Science.gov (United States)

    Venugopal, S.; Sathish, S.; Jothi Prakash, V. M.; Gopalakrishnan, T.

    2017-03-01

    Abrasive water jet cutting is one of the most recently developed non-traditional manufacturing technologies. In this machining, the abrasives are mixed with suspended liquid to form semi liquid mixture. The general nature of flow through the machining, results in fleeting wear of the nozzle which decrease the cutting performance. The inlet pressure of the abrasive water suspension has main effect on the major destruction characteristics of the inner surface of the nozzle. The aim of the project is to analyze the effect of inlet pressure on wall shear and exit kinetic energy. The analysis could be carried out by changing the taper angle of the nozzle, so as to obtain optimized process parameters for minimum nozzle wear. The two phase flow analysis would be carried by using computational fluid dynamics tool CFX. It is also used to analyze the flow characteristics of abrasive water jet machining on the inner surface of the nozzle. The availability of optimized process parameters of abrasive water jet machining (AWJM) is limited to water and experimental test can be cost prohibitive. In this case, Computational fluid dynamics analysis would provide better results.

  13. [Water jet cutting for bones and bone cement--parameter study of possibilities and limits of a new method].

    Science.gov (United States)

    Honl, M; Rentzsch, R; Lampe, F; Müller, V; Dierk, O; Hille, E; Louis, H; Morlock, M

    2000-09-01

    Water jet techniques have been used in industrial cutting, drilling and cleaning applications for more than 30 years. Plain water is typically used for the cutting of non-metallic materials. The addition of abrasive substances to the stream allows almost any material to be cut. The first medical applications were reported in the early 1980s, when the water jet was used to cut organs. The present study investigates the use of water jet cutting technology for endoprosthesis revision surgery. Bone and PMMA (polymethylmethacrylate) samples were cut at different pressures using an industrial water jet cutting device. Using plain water at 400 bar, PMMA was cut selectively without damaging the bone; above 400 bar, bone was also cut, but the cutting depths in PMMA were significantly greater (p water-soluble abrasive disaccharide to the water results in a significantly higher removal rate for both materials (p cutting depth between the two materials was significant (p abrasive, the quality of the cut was better for both materials. The water jet technology--in particular the abrasive technique--can be used to cut biomaterials such as bone and bone cement. The diameter of the jet is a great advantage when working in the confined area at the prosthesis interface. The cutting process is essentially cold, thus eliminating a thermal effect, and the jet reaction forces are relatively low. Accurate manipulation of the hydro jet nozzle is possible both manually and by robot. The results obtained show that it is possible to remove prostheses with this cutting technique, rapidly and with little damage to the surrounding tissue. Problem areas are the development of sterile pumps and the "depth control" of the jet.

  14. New Application of Actuator-Driven Pulsed Water Jet for Spinal Cord Dissection: An Experimental Study in Pigs.

    Science.gov (United States)

    Endo, Toshiki; Wenting, Jia; Nakagawa, Atsuhiro; Endo, Hidenori; Sagae, Yuto; Iwasaki, Masaki; Tominaga, Teiji

    2017-03-01

    Background Surgery for intramedullary tumors is technically demanding because it requires surgical resection along with functional preservation of the spinal cord. The water jet dissector is an emerging tool in neurologic surgeries and a novel tool in spinal cord surgeries. This article evaluates the usefulness and safety of water jet dissection in an experimental study. Methods A pulsed water jet was applied to dissect the posterior median sulcus of the spinal cords of seven anesthetized pigs. In four pigs, the water jet was delivered on the dorsal spinal cord at different input voltages (5, 10, and 15 V) and for durations of either 15 or 30 seconds. The depth and dissected areas were measured histologically and compared. In three separate pigs, somatosensory evoked potentials (SEPs) were recorded before and after dissection (10 V for 30 seconds) to evaluate the function of the dorsal column sensory pathway. Results Increased pressure and duration of exposure to the pulsed water jet led to deeper and wider dissection of the dorsal spinal cord. Application of the water jet at 5 or 10 V allowed precise dissection along the dorsal columns along with the preservation of microvasculature. During SEP monitoring, responses were maintained after application of the water jet to the posterior column at 10 V for 30 seconds. Conclusions The pulsed water jet is a feasible option for spinal cord dissection. Characteristics of this water jet may help surgeons achieve complete resection of intramedullary tumors along with preserving satisfactory postoperative neurologic functions. Georg Thieme Verlag KG Stuttgart · New York.

  15. Ultrasound elastomicroscopy using water jet and osmosis loading: potentials for assessment for articular cartilage.

    Science.gov (United States)

    Zheng, Yong-Ping; Lu, Min-Hua; Wang, Qing

    2006-12-22

    Research in elasticity imaging typically relies on 1-10 MHz ultrasound. Elasticity imaging at these frequencies can provide strain maps with a resolution in the order of millimeters, but this is not sufficient for applications to skin, articular cartilage, or other fine structures. In this paper, we introduced two methods of ultrasound elastomicroscopy using water jet and osmosis loading for imaging the elasticity of biological soft tissues with high resolutions. In the first system, the specimens were compressed using water jet compression. A water jet was used to couple a focused 20 MHz ultrasound beam into the specimen and meanwhile served as a "soft" indenter. Because there was no additional attenuation when propagating from the ultrasound transducer to the specimen, the ultrasound signal with high signal-to-noise ratio could be collected from the specimens simultaneously with compressing process. The compression was achieved by adjusting the water flow. The pressure measured inside the water pipe and that on the specimen surface was calibrated. This system was easily to apply C-scan over sample surfaces. Experiments on the phantoms showed that this water jet indentation method was reliable to map the tissue stiffness distribution. Results of 1D and 2D scanning on phantoms with different stiffness are reported. In the second system, we used osmotic pressure caused by the ion concentration change in the bathing solutions for the articular cartilage to deform them. When bovine articular cartilage specimens were immerged in solutions with different salt concentration, a 50 MHz focused ultrasound beam was used to monitor the dynamic swelling or shrinkage process. Results showed that the system could reliably map the strain distribution induced by the osmotic loading. We extract intrinsic layered material parameters of the articular cartilage using a triphasic model. In addition to biological tissues, these systems have potential applications for the assessment of

  16. Optimization MRR Of Stainless Steel 403 In Abrasive Water Jet Machining UsingAnova And Taguchi Method

    Directory of Open Access Journals (Sweden)

    Ramprasad,

    2015-05-01

    Full Text Available Stainlesssteel 403 is high-alloysteelwith good corrosion resistance and it’svery hard material. Abrasive water jet is an effective method for machining, cutting and drilling of stainlesssteel 403. In thispaperweoptimize the metalremoval rate of stainlesssteel 403 in abrasive water jet machining. The MRRisoptimize by usingthreeparameters water pressure, abrasive flow rate and stand-off distance and L9 orthogonal array of Taguchimethod use to analyse the result. 9 experimentalrunsbased on L9 orthogonal array of Taguchimethod.

  17. Median Nerve Injury Due to High-Pressure Water Jet Injection: A Case Report and Review of Literature.

    Science.gov (United States)

    Emre, Ufuk; Unal, Aysun

    2009-08-01

    High-pressure injuries that occur accidentally are potentially destructive injuries that often affect the nondominant hands of young men. A variety of products such as paint, gasoline, grease, fuel oil, cement, thinner and solvents have been reported as destructive agents. High-pressure water jet injection injuries to soft tissues have rarely been reported. In this study, we present the first case of median nerve injury due to high-pressure water jet injection by a water spray gun.

  18. Numerical and Experimental Studies of Cavitation Behavior in Water-Jet Cavitation Peening Processing

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2013-01-01

    Full Text Available Water-jet cavitation peening (WCP is a new technology for the surface modification of metallic materials. The cavitation behavior in this process involves complex and changeable physics phenomena, such as high speed, high pressure, multiple phases, phase transition, turbulence, and unstable features. Thus, the cavitation behavior and impact-pressure distribution in WCP have always been key problems in this field. Numerous factors affect the occurrence of cavitation. These factors include flow-boundary conditions, absolute pressure, flow velocity, flow viscosity, surface tension, and so on. Among these factors, pressure and vapor fraction are the most significant. Numerical simulations are performed to determine the flow-field characteristics of both inside and outside the cavitating nozzle of a submerged water jet. The factors that influence the cavitation intensity of pressure are simulated. Fujifilm pressure-sensitive paper is used to measure the distribution of impact pressure along the jet direction during the WCP process. The results show that submerged cavitation jets can induce cavitation both inside and outside a conical nozzle and a convergent-divergent nozzle when the inlet pressure is 32 MPa. Moreover, the shock wave pressure induced by the collapse of the bubble group reaches up to 300 MPa.

  19. Water Spray Flow Characteristics Under Synthetic Jet Driven By a Piezoelectric Actuator

    Science.gov (United States)

    Marchitto, L.; Valentino, G.; Chiatto, M.; de Luca, L.

    2017-01-01

    Particle Image Velocimetry (PIV) and Phase Doppler Anemometry (PDA) have been applied to investigate the droplets size and velocity distribution of a water spray, under the control of a piezo-element driven synthetic jet (SJ). Tests were carried out under atmospheric conditions within a chamber test rig equipped with optical accesses at two injection pressures, namely 5 and 10 MPa, exploring the variation of the main spray parameters caused by the synthetic jet perturbations. The SJ orifice has been placed at 45° with respect to the water spray axis; the nozzle body has been moved on its own axis and three different nozzle quotes were tested. PIV measurements have been averaged on 300 trials whereas about 105 samples have been acquired for the PDA tests. For each operative condition, the influence region of the SJ device on the spray has been computed through a T-Test algorithm. The synthetic jet locally interacts with the spray, energizing the region downstream the impact. The effect of the actuator decreases at higher injection pressures and moving the impact region upwards. Droplets coalescence can be detected along the synthetic jet axis, while no significant variations are observed along a direction orthogonal to it.

  20. Multiphase Flow and Wear in the Cutting Head of Ultra-high Pressure Abrasive Water Jet

    Institute of Scientific and Technical Information of China (English)

    YANG Minguan; WANG Yuli; KANG Can; YU Feng

    2009-01-01

    Abrasive water jet cutting technology is widely applied in the materials processing today and attracts great attention from scholars, but many phenomena concerned are not well understood, especially in the internal jet flow of the cutting head at the condition of ultra-high pressure. The multiphase flow in the cutting head is numerically simulated to study the abrasive motion mechanism and wear inside the cutting head at the pressure beyond 300 Mpa. Visible predictions of the particles trajectories and wear rate in the cutting head are presented. The influences of the abrasive physical properties, size of the jewel orifice and the operating pressure on the trajectories are discussed. Based on the simulation, a wear experiment is carried out under the corresponding pressures. The simulation and experimental results show that the flow in the mixing chamber is composed of the jet core zone and the disturbance zone, both affect the particles trajectories. The mixing efficiency drops with the increase of the abrasive granularity. The abrasive density determines the response of particles to the effects of different flow zones, the abrasive with medium density gives the best general performance. Increasing the operating pressure or using the jewel with a smaller orifice improves the coherency of particles trajectories but increases the wear rate of the jewel holder at the same time. Walls of the jewel holder, the entrance of the mixing chamber and the convergence part of the mixing tube are subject to wear out. The computational and experimental results give a qualitative consistency which proves that this numerical method can provide a reliable and visible cognition of the flow characteristics of ultra-high pressure abrasive water jet. The investigation is benefit for improving the machining properties of water jet cutting systems and the optimization design of the cutting head.

  1. Application of a water jet system to the pretreatment of cellulose.

    Science.gov (United States)

    Watanabe, Yuka; Kitamura, Shinichi; Kawasaki, Kazunori; Kato, Tomoki; Uegaki, Koichi; Ogura, Kota; Ishikawa, Kazuhiko

    2011-12-01

    Plant cellulose is the most abundant organic compound on earth. Technologies for producing cellulose fiber or improving the enzymatic saccharification of cellulose hold the key to biomass applications. A technology for atomizing biomass without strong acid catalysis remains to be developed. The water jet is a well-known device used in machines (e.g., washing machines, cutters, and mills) that use high-pressure water. In this study, we examined whether a water jet system could be used to atomize crystalline cellulose, which comprises approximately 50% of plant biomass. The Star Burst System manufactured by Sugino Machine Limited (Sugino Machine; Toyama, Japan) is a unique atomization machine that uses a water jet to atomize materials and thereby places lower stress on the environment. After treatment with this system, the crystalline cellulose was converted into a gel-like form. High-angular annular dark-field scanning transmission electron microscopy showed that the cellulose fibers had been converted from a solid crystalline into a matrix of cellulose nanofibers. In addition, our results show that this system can improve the saccharification efficiency of cellulases by more than three-fold. Hence, the Star Burst System provides a new and mild pretreatment system for processing biomass materials. 2011 Wiley Periodicals, Inc.

  2. Performance optimization of water-jet assisted underwater laser cutting of AISI 304 stainless steel sheet

    Science.gov (United States)

    Mullick, Suvradip; Madhukar, Yuvraj K.; Roy, Subhransu; Nath, Ashish K.

    2016-08-01

    Recent development of water-jet assisted underwater laser cutting has shown some advantages over the gas assisted underwater laser cutting, as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. Scattering is reported to be a dominant loss mechanism, which depends on the growth of vapor layer at cut front and its removal by water-jet. Present study reports improvement in process efficiency by reducing the scattering loss using modulated laser power. Judicious control of laser pulse on- and off-time could improve process efficiency through restricting the vapor growth and its effective removal by water-jet within the laser on- and off-time, respectively. Effects of average laser power, duty cycle and modulation frequency on specific energy are studied to get an operating zone for maximum efficiency. Next, the variation in laser cut quality with different process parameters are studied within this operating zone using Design of experiment (DOE). Response surface methodology (RSM) is used by implementing three level Box-Behnken design to optimize the variation in cut quality, and to find out the optimal process parameters for desired quality. Various phenomena and material removal mechanism involved in this process are also discussed.

  3. Simplified Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection

    Science.gov (United States)

    Molnar, Melissa; Marek, C. John

    2005-01-01

    A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20). The results presented here results in a correlation that gives the chemical kinetic time as two separate functions. This two time step method is used as opposed to a one step time averaged method previously developed to determine the chemical kinetic time with increased accuracy. The first time averaged step is used at the initial times for smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, initial water to fuel mass ratio, temperature, and pressure. The second instantaneous step, to be used with higher water concentrations, gives the chemical kinetic time as a function of instantaneous fuel and water mole concentration, pressure and temperature (T4). The simple correlations would then be compared to the turbulent mixing times to determine the limiting rates of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates are used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide and NOx are obtained for Jet-A fuel and methane with and without water injection to water mass loadings of 2/1 water to fuel. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentrations of carbon monoxide and nitrogen oxide as functions of overall equivalence ratio, water to fuel mass ratio, pressure and temperature (T3). The temperature of the gas entering

  4. New Reduced Two-Time Step Method for Calculating Combustion and Emission Rates of Jet-A and Methane Fuel With and Without Water Injection

    Science.gov (United States)

    Molnar, Melissa; Marek, C. John

    2004-01-01

    A simplified kinetic scheme for Jet-A, and methane fuels with water injection was developed to be used in numerical combustion codes, such as the National Combustor Code (NCC) or even simple FORTRAN codes that are being developed at Glenn. The two time step method is either an initial time averaged value (step one) or an instantaneous value (step two). The switch is based on the water concentration in moles/cc of 1x10(exp -20). The results presented here results in a correlation that gives the chemical kinetic time as two separate functions. This two step method is used as opposed to a one step time averaged method previously developed to determine the chemical kinetic time with increased accuracy. The first time averaged step is used at the initial times for smaller water concentrations. This gives the average chemical kinetic time as a function of initial overall fuel air ratio, initial water to fuel mass ratio, temperature, and pressure. The second instantaneous step, to be used with higher water concentrations, gives the chemical kinetic time as a function of instantaneous fuel and water mole concentration, pressure and temperature (T4). The simple correlations would then be compared to the turbulent mixing times to determine the limiting properties of the reaction. The NASA Glenn GLSENS kinetics code calculates the reaction rates and rate constants for each species in a kinetic scheme for finite kinetic rates. These reaction rates were then used to calculate the necessary chemical kinetic times. Chemical kinetic time equations for fuel, carbon monoxide and NOx were obtained for Jet-A fuel and methane with and without water injection to water mass loadings of 2/1 water to fuel. A similar correlation was also developed using data from NASA's Chemical Equilibrium Applications (CEA) code to determine the equilibrium concentrations of carbon monoxide and nitrogen oxide as functions of overall equivalence ratio, water to fuel mass ratio, pressure and temperature (T3

  5. Benchmarking the GENE and GYRO codes through the relative roles of electromagnetic and E  ×  B stabilization in JET high-performance discharges

    Science.gov (United States)

    Bravenec, R.; Citrin, J.; Candy, J.; Mantica, P.; Görler, T.; contributors, JET

    2016-12-01

    Nonlinear gyrokinetic simulations using the GENE code have previously predicted a significant nonlinear enhanced electromagnetic stabilization in certain JET discharges with high neutral-beam power and low core magnetic shear (Citrin et al 2013 Phys. Rev. Lett. 111 155001, 2015 Plasma Phys. Control. Fusion 57 014032). This dominates over the impact of E  ×  B flow shear in these discharges. Furthermore, fast ions were shown to be a major contributor to the electromagnetic stabilization. These conclusions were based on results from the GENE gyrokinetic turbulence code. In this work we verify these results using the GYRO code. Comparing results (linear frequencies, eigenfunctions, and nonlinear fluxes) from different gyrokinetic codes as a means of verification (benchmarking) is only convincing if the codes agree for more than one discharge. Otherwise, agreement may simply be fortuitous. Therefore, we analyze three discharges, all with a carbon wall: a simplified, two-species, circular geometry case based on an actual JET discharge; an L-mode discharge with a significant fast-ion pressure fraction; and a low-triangularity high-β hybrid discharge. All discharges were analyzed at normalized toroidal flux coordinate ρ  =  0.33 where significant ion temperature peaking is observed. The GYRO simulations support the conclusion that electromagnetic stabilization is strong, and dominates E  ×  B shear stabilization.

  6. Ultra-high pressure water jet: Baseline report; Greenbook (chapter)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The technologies being tested for concrete decontamination are targeted for alpha contamination. The safety and health evaluation during the human factors assessment focused on two main areas: noise and dust.

  7. Ultra-high pressure water jet: Baseline report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-31

    The ultra-high pressure waterjet technology was being evaluated at Florida International University (FIU) as a baseline technology. In conjunction with FIU`s evaluation of efficiency and cost, this report covers the evaluation conducted for safety and health issues. It is a commercially available technology and has been used for various projects at locations throughout the country. The ultra-high pressure waterjet technology acts as a cutting tool for the removal of surface substrates. The Husky{trademark} pump feeds water to a lance that directs the high pressure water at the surface to be removed. The safety and health evaluation during the testing demonstration focused on two main areas of exposure. These were dust and noise. The dust exposure was found to be minimal, which would be expected due to the wet environment inherent in the technology, but noise exposure was at a significant level. Further testing for noise is recommended because of the outdoor environment where the testing demonstration took place. In addition, other areas of concern found were arm-hand vibration, ergonomics, heat stress, tripping hazards, electrical hazards, lockout/tagout, fall hazards, slipping hazards, hazards associated with the high pressure water, and hazards associated with air pressure systems.

  8. Clinical Experience in Using the Water Jet in Burn Wound Debridement

    Science.gov (United States)

    Yang, J.-Y.; Hwuang, J.-Y.; Chuang, S.-S.

    2007-01-01

    Summary Water jets have been used in many areas of surgery. Recently a new surgical debridement device was launched onto the market - VersajetTM. VersajetTM is a unique hydrosurgical device that uses a precise jet of water to simultaneously hold, cut, and remove devitalized or necrotic tissue. This paper describes our experience with ten patients comparing Weck knives with the newly designed hydrosurgical device when debriding burn wounds. The patients' age ranged from 27 to 60 yr (average, 37.8 yr) and the burn wounds treated were between 3 and 7% total body surface area, involving the face, abdomen, and limbs. The hydrosurgical system is a very useful tool for irregular and complex burn wound debridement. This paper represents the first written clinical experience utilizing hydrosurgery in the burn wound management in an Eastern country. PMID:21991073

  9. Multi-objective Optimization of Process Performances when Cutting Carbon Steel with Abrasive Water Jet

    Directory of Open Access Journals (Sweden)

    M. Radovanović

    2016-12-01

    Full Text Available Multi-objective optimization of process performances (perpendicularity deviation, surface roughness and productivity when cutting carbon steel EN S235 with abrasive water jet is presented in this paper. Cutting factors (abrasive flow rate, traverse rate and standoff distance were determined when perpendicularity deviation and surface roughness are minimal and productivity is maximal. Multi-objective genetic algorithm (MOGA was used for the determination set of nondominated optimal points, known as Pareto front.

  10. Evaluation of bone-tendon junction healing using water jet ultrasound indentation method.

    Science.gov (United States)

    Lu, Min-Hua; Zheng, Yong-Ping; Lu, Hong-Bin; Huang, Qing-Hua; Qin, Ling

    2009-11-01

    The re-establishment of bone-tendon junction (BTJ) tissues with the junction, characterized as a unique transitional fibrocartilage zone, is involved in many trauma and reconstructive surgeries. Experimental and clinical findings have shown that a direct BTJ repair requires a long period of immobilization, which may be associated with a postoperative weak knee. Therefore, it is necessary to evaluate the morphologic and mechanical properties of BTJ tissues in situ to better understand the healing process for the purpose of reducing the adverse effects of immobilization. We previously reported a noncontact ultrasound water jet indentation system for measuring and mapping tissue mechanical properties. The key idea was to utilize a water jet as an indenter as well as the coupling medium for high-frequency ultrasound. In this article, we used ultrasound water jet indentation to evaluate the BTJ healing process. The system's capability of measuring the material elastic modulus was first validated using tissue-mimicking phantoms. Then it was employed to assess the healing of the BTJ tissues after partial patellectomy over time on twelve 18-week-old female New Zealand White rabbits. It was found that in comparison with the normal control samples, the elastic modulus of the fibrocartilage of the postoperative samples was significantly smaller, while its thickness increased significantly. Among the postoperative sample groups, the elastic modulus of the fibrocartilage of the samples harvested at week 18 was significantly higher than those harvested at week 6 and week 12, which was even comparable with the value of the control samples at the same sacrifice time. The results suggested that the noncontact ultrasound water jet indentation system provided a nondestructive way to evaluate the material properties of small animal tissues in situ and thus had the ability to evaluate the healing process of BTJ.

  11. Water jet with adjunct chlorhexidine gel for nonsurgical treatment of peri-implantitis.

    Science.gov (United States)

    Levin, Liran; Frankenthal, Shai; Joseph, Livia; Rozitsky, Doron; Levi, Guy; Machtei, Eli E

    2015-02-01

    Peri-implant disease following successful integration of an endosseous implant is the result of an imbalance between bacterial load and host defense, which may affect not only the peri-implant mucosa but also involve the supporting bone. The aim of this study was to evaluate the adjunctive effect of a dental water jet rinse mixed with chlorhexidine gel to the nonsurgical treatment for peri-implantitis. A prospective randomized interventional cohort study was conducted. Forty consecutive patients presenting with peri-implantitis were recruited and randomly assigned into two treatment groups. Initially all patients received scaling/surface debridement and oral hygiene instruction. Patients in the study group received a water jet device containing chlorhexidine gel (Silonite®) for home use twice daily while the control group performed the recommended oral hygiene measures with no water jet usage. Three months following baseline visit, patients were reevaluated clinically and radiographically. In total, 39 patients completed the study and were available for final examination. Three months following baseline visit the test group exhibited greater mean probing depth reduction (0.75 mm vs 0.27 mm; P = .029) as well as greater reduction in the number of sites presenting with bleeding on probing (2.26 vs 0.45 sites; P = .011). No significant change in bone level was observed at 3 months (mean bone gain was 0.18 mm). Water jet mixed with chlorhexidine gel might supplement the response to nonsurgical treatment for peri-implantitis lesions. Further, larger-cohort studies are warranted.

  12. Using of abrasive water jet for measurement of residual stress in railway wheels

    OpenAIRE

    Hlaváček, P. (Petr); Brumek, J.; Horsák, L.

    2012-01-01

    The paper provides a general introduction to methods of measurement of residual stresses on railway wheels. Determination of residual stress distribution is necessary for the prediction of wheel service life and possible catastrophic failure. Therefore experimental section is devoted to residual stress measurement using strain gauges according to standard EN 13262 + A1. During measurement, several segments of tested wheel were cut by abrasive water jet to detect changes of residual stresses o...

  13. Water-jet guided laser: possibilities and potential for singulation of electronic packages

    Science.gov (United States)

    Wagner, Frank R.; Spiegel, Akos; Vago, Nandor; Richerzhagen, Bernold

    2002-06-01

    Singulation of packages is an important step in the manufacturing of IC devices. Presently, the most widely used technique is abrasive sawing. Due to the combination of different materials used in packages such as copper and mold compound, the saw rapidly blunts and also conventional laser cutting by a water-jet with the high precision and speed of a laser cut and is now applied into electronic package singulation.

  14. Electrochemical degradation of reactive dye in the presence of water jet cavitation.

    Science.gov (United States)

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2010-03-01

    Degradation of a reactive dye, Brilliant Red X-3B, induced by electrolysis coupled with water jet cavitation was studied. The experiment was performed in 4.5L of aqueous solution containing X-3B concentrations ranging from 40 to 120mg/L by applying Ti-IrO(2) as anode and graphite as cathode. The water jet cavitation process decreased the diffusion layer thickness and consequently increased the current density. Compared to water jet cavitation and electrolysis alone, the combination of the two methods enhanced X-3B removal and showed a synergistic effect. The azo bond of the dye molecule was broken down and the naphthalene ring was transformed to multi-substituted benzene during the combined process. The dye degradation rate increased with increasing concentration. Acidic conditions (e.g., pH 1) favored the decolorization of the reactive dye. The use of TiO(2) coated with IrO(2) as anode and graphite as cathode showed the best performance for the dye removal efficiency, compared to other electrode pairs. Addition of SO(4)(2-), NO(3)(-), and especially Cl(-) ions into solution significantly enhanced the degradation. However, CO(3)(2-) inhibited the dye decolorization. Copyright 2009 Elsevier B.V. All rights reserved.

  15. Use of Actuator-Driven Pulsed Water Jet in Brain and Spinal Cord Cavernous Malformations Resection.

    Science.gov (United States)

    Endo, Toshiki; Takahashi, Yoko; Nakagawa, Atsuhiro; Niizuma, Kuniyasu; Fujimura, Miki; Tominaga, Teiji

    2015-09-01

    A piezo actuator-driven pulsed water jet (ADPJ) system is a novel surgical instrument that enables dissection of tissue without thermal damage. It can potentially resect intra-axial lesions while preserving neurological function. To report our first experience of applying an ADPJ system to brain and spinal cord cavernous malformations. Four patients (2 women and 2 men, mean age 44.5 years) with brain (n = 3) and spinal cord (n = 1) cavernous malformations were enrolled in the study. All surgeries were performed with the aid of the ADPJ system. Postoperative neurological function and radiological findings were evaluated. The ADPJ system was useful in dissecting boundaries between the lesion and surrounding brain/spinal cord tissues. The pulsed water jet provided a clear surgical view and helped surgeons follow the margins. Water jet dissection peeled off the brain and spinal cord tissues from the lesion wall. Surrounding gliotic tissue was preserved. As a consequence, the cavernous malformations were successfully removed. Postoperative magnetic resonance imaging confirmed total removal of lesions in all cases. Preoperative neurological symptoms completely resolved in 2 patients. The others experienced partial recovery. No patients developed new postoperative neurological deficits; facial palsy temporarily worsened in 1 patient who underwent a suprafacial colliculus approach for the brainstem lesion. The ADPJ provided a clear surgical field and enabled surgeons to dissect boundaries between lesions and surrounding brain and spinal cord gliotic tissue. The ADPJ system is a feasible option for cavernous malformation surgery, enabling successful tumor removal and preservation of neurological function.

  16. Noncontact evaluation of articular cartilage degeneration using a novel ultrasound water jet indentation system.

    Science.gov (United States)

    Lu, M-H; Zheng, Y P; Huang, Q-H; Ling, C; Wang, Q; Bridal, L; Qin, L; Mak, A

    2009-01-01

    We previously reported a noncontact ultrasound water jet indentation system for measuring and mapping tissue mechanical properties. The key idea was to utilize a water jet as an indenter as well as the coupling medium for high-frequency ultrasound. In this paper, the system was employed to assess articular cartilage degeneration, using stiffness ratio as an indicator of the mechanical properties of samples. Both the mechanical and acoustical properties of intact and degenerated bovine patellar articular cartilage (n = 8) were obtained in situ. It was found that the stiffness ratio was reduced by 44 +/- 17% after the articular cartilage was treated by 0.25% trypsin at 37 degrees C for 4 h while no significant difference in thickness was observed between the intact and degenerated samples. A significant decrease of 36 +/- 20% in the peak-to-peak amplitude of ultrasound echoes reflected from the cartilage surface was also found for the cartilage samples treated by trypsin. The results also showed that the stiffness obtained with the new method highly correlated with that measured using a standard mechanical testing protocol. A good reproducibility of the measurements was demonstrated. The present results showed that the ultrasound water jet indentation system may provide a potential tool for the non-destructive evaluation of articular cartilage degeneration by simultaneously obtaining mechanical properties, acoustical properties, and thickness data.

  17. Investigation of Turbulent Tip Leakage Vortex in an Axial Water Jet Pump with Large Eddy Simulation

    Science.gov (United States)

    Hah, Chunill; Katz, Joseph

    2012-01-01

    Detailed steady and unsteady numerical studies were performed to investigate tip clearance flow in an axial water jet pump. The primary objective is to understand physics of unsteady tip clearance flow, unsteady tip leakage vortex, and cavitation inception in an axial water jet pump. Steady pressure field and resulting steady tip leakage vortex from a steady flow analysis do not seem to explain measured cavitation inception correctly. The measured flow field near the tip is unsteady and measured cavitation inception is highly transient. Flow visualization with cavitation bubbles shows that the leakage vortex is oscillating significantly and many intermittent vortex ropes are present between the suction side of the blade and the tip leakage core vortex. Although the flow field is highly transient, the overall flow structure is stable and a characteristic frequency seems to exist. To capture relevant flow physics as much as possible, a Reynolds-averaged Navier-Stokes (RANS) calculation and a Large Eddy Simulation (LES) were applied for the current investigation. The present study reveals that several vortices from the tip leakage vortex system cross the tip gap of the adjacent blade periodically. Sudden changes in local pressure field inside tip gap due to these vortices create vortex ropes. The instantaneous pressure filed inside the tip gap is drastically different from that of the steady flow simulation. Unsteady flow simulation which can calculate unsteady vortex motion is necessary to calculate cavitation inception accurately even at design flow condition in such a water jet pump.

  18. Experimental study on immiscible jet breakup using refractive index matched oil-water pair

    Science.gov (United States)

    Xue, Xinzhi; Katz, Joseph

    2016-11-01

    A subsea oil well blowout creates an immiscible crude oil jet. This jet fragments shortly after injection, resulting in generation of a droplet cloud. Detailed understanding of the processes involved is crucial for modeling the fragmentation and for predicting the droplet size distribution. High density of opaque droplets near nozzle limits our ability to visualize and quantify the breakup process. To overcome this challenge, two immiscible fluids: silicone oil and sugar water with the same index of refraction (1.4015) are used as surrogates for crude oil and seawater, respectively. Their ratios of kinematic viscosity (5.64), density (0.83) and interfacial tension are closely matched with those of crude oil and seawater. Distribution of the oil phase is visualized by fluorescent tagging. Both phases are also seeded with particles for simultaneous PIV measurements. The measurements are performed within atomization range of Ohnesorge and Reynolds numbers. Index matching facilitates undistorted view of the phase distribution in illuminated section. Ongoing tests show that the jet surface initially rolls up into Kelvin-Helmholtz rings, followed by development of dispersed phase ligaments further downstream, which then break into droplets. Some of these droplets are re-entrained into the high momentum core, resulting in secondary breakup. As the oil layer and ligaments evolve, they often entrain water, resulting in generation of multiple secondary water droplets encapsulated within the oil droplets. This research is made possible by a Grant from Gulf of Mexico Research Initiative.

  19. [Endoscopic use of the water jet dissector in the cerebral ventricle system--an experimental study].

    Science.gov (United States)

    Jakob, S; Kehler, U; Reusche, E; Friedrich, H J; Arnold, H

    2000-01-01

    Endoscopic surgery in the cerebral ventricle is limited by the small number of suitable instruments and bleedings obscuring the visibility. The water jet cutter allows the dissection of tissue, generally leaving vessels intact. Therefore it could be an additional instrument for neuroendoscopic purposes. In this preclinical study the employment of the water jet dissector under endoscopic conditions was evaluated. Incision-experiments (n = 80) on the ventricular system of fresh porcine brain were carried out under endoscopic view. To achieve similarity to the ventricular system, specimens were dissected in liquid medium (Ringer's-lactate, 37 degrees C). The depths of incision were measured digitally and histological examination of the tissue was performed. Depending on the applied pressure, distance from cutting nozzle to tissue and cutting velocity, the depths of incision ranged from 0.12 mm up to 2.4 mm. The water jet dissector is good to handle under endoscopic conditions and vessels are preserved. Based on these factors, this instrument is predestinated for further neuroendoscopic application. Prior to clinical application our results will have to be tested on living, perfused cerebral tissue.

  20. Simulation of the flow obstruction of a jet pump in a BWR reactor with the code RELAP/SCDAPSIM; Simulacion de la obstruccion de flujo de una bomba jet en un reactor BWR con el codigo RELAP/SCDAPSIM

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas V, J.; Filio L, C., E-mail: jaime.cardenas@cnsns.gob.mx [Comision Nacional de Seguridad Nuclear y Salvaguardias, Dr. Jose M. Barragan 779, Col. Narvarte, 03020 Ciudad de Mexico (Mexico)

    2016-09-15

    This work simulates the flow obstruction of a jet pump in one of the recirculation loops of a nuclear power plant with a reactor of type BWR at 100% of operating power, in order to analyze the behavior of the total flow of the refrigerant passing through the reactor core, the total flow in each recirculation loop of the reactor, together with the 10 jet pumps of each loop. The behavior of the power and the reactivity insertion due to the change of the refrigerant flow pattern is also analyzed. The simulation was carried out using the RELAP/SCDAPSIM version 3.5 code, using a reactor model with 10 jet pumps in each recirculation loop and a core consisting of 6 radial zones and 25 axial zones. The scenario postulates the flow obstruction in a jet pump in a recirculation loop A when the reactor operates at 100% rated power, causing a change in the total flow of refrigerant in the reactor core, leading to a decrease in power. Once the reactor conditions are established to its new power, the operator tries to recover the nominal power using the flow control valve of the recirculation loop A, opening stepwise as a strategy to safely recover the reactor power. In this analysis is assumed that the intention of the nuclear plant operator is to maintain the operation of the reactor during the established cycle. (Author)

  1. Rock Breaking Performance of a Pick Assisted by High-pressure Water Jet under Different Configuration Modes

    Institute of Scientific and Technical Information of China (English)

    LIU Songyong; LIU Xiaohui; CHEN Junfeng; LIN Mingxing

    2015-01-01

    In the process of rock breaking, the conical pick bears great cutting force and wear, as a result, high-pressure water jet technology is used to assist with cutting. However, the effect of the water jet position has not been studied for rock breaking using a pick. Therefore, the models of rock breaking with different configuration modes of the water jet are established based on SPH combined with FEM. The effect of the water jet pressure, distance between the jet and the pick bit, and cutting depth on the rock breaking performance as well as a comparison of the tension and compression stress are studied via simulation; the simulation results are verified by experiments. The numerical and experimental results indicate that the decrease in the rates of the pick force obviously increases from 25 MPa to 40 MPa, but slowly after 40 MPa, and the optimal distance between the jet and the pick bit is 2 mm under the JFP and JSP modes. The JCP mode is proved the best, followed by the modes of JRP and JFP, and the worst mode is JSP. The decrease in the rates of the pick force of the JCP, JRP, JFP, and JSP modes are up to 30.96%, 28.96%, 33.46%, 28.17%, and 25.42%, respectively, in experiment. Moreover, the JSP mode can be regarded as a special JFP model when the distance between the pick-tip and the jet impact point is 0 mm. This paper has a dominant capability in introducing new numerical and experimental method for the study of rock breaking assisted by water jet and electing the best water jet position from four different configuration modes.

  2. Uniform and non-uniform inlet temperature of a vertical hot water jet injected into a rectangular tank

    KAUST Repository

    El-Amin, Mohamed

    2010-12-01

    In most of real-world applications, such as the case of heat stores, inlet is not kept at a constant temperature but it may vary with time during charging process. In this paper, a vertical water jet injected into a rectangular storage tank is measured experimentally and simulated numerically. Two cases of study are considered; one is a hot water jet with uniform inlet temperature (UIT) injected into a cold water tank, and the other is a cold water jet with non-uniform inlet temperature (NUIT) injected into a hot water tank. Three different temperature differences and three different flow rates are studied for the hot water jet with UIT which is injected into a cold water tank. Also, three different initial temperatures with constant flow rate as well as three different flow rates with constant initial temperature are considered for the cold jet with NUIT which is injected into a hot water tank. Turbulence intensity at the inlet as well as Reynolds number for the NUIT cases are therefore functions of inlet temperature and time. Both experimental measurements and numerical calculations are carried out for the same measured flow and thermal conditions. The realizable k-ε model is used for modeling the turbulent flow. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank are analyzed. The simulated results are compared to the measured results, and they show a good agreement at low temperatures. © 2010 IEEE.

  3. Impact jetting water ice, with application to the accretion of icy planetesimals and Pluto

    Energy Technology Data Exchange (ETDEWEB)

    McKinnon, W.B. (Washington Univ., Seattle (USA))

    1989-11-01

    Jetting can occur during oblique impacts of water ice bodies at relative velocities at low as {approximately}500 m s{sup {minus}1}, because of the low Hugoniot elastic limit and high compressibility of ice compared to rock. In jetted ice, incipient melting, complete melting, and incipient vaporization occur, upon release to low pressure, at impact velocities of 1.3, 2.0, and 2.7 km s{sup {minus}1}, respectively, much less than the 3.4, 4.4, and 5.3 km s{sup {minus}1} required in head-on collisions. Uncertainties in the shock equation-of-state may allow complete melting during jetting at relative velocities as low as 1.2 km s{sup {minus}1}. Because jet speeds exceed impact speeds, often by a factor of several, during the accretion of icy bodies greater than a few 100 km in radius there any be a significant loss of icy material. This is more true if the accreting body is large enough to differentiate so that its surface layers are closer to pure ice in composition, and especially true if bodies of comparable size are involved, which emphasizes the obliqueness of the collision. The author suggests that it is jetting during a Charon-forming collision (and not vaporization) that may account for Pluto-Charon's relatively large rock/ice ratio, should the C/O ratio of the solar nebula turn out too low to sufficiently raise the rock/ice ratio of outer solar nebula condensates by formation of non-condensable CO.

  4. Study of kerf geometry of multilayers materials in abrasive water jet cutting process

    Directory of Open Access Journals (Sweden)

    Barabas Bogdan

    2017-01-01

    Full Text Available The use of abrasive jet cutting in case of multilayers materials, shows particularities and difficulties, due to different hardness and thickness of layers. This paper studies changes, occurred in the kerf geometry at passing of abrasive particles, through layers with different hardness and aims to establish a link between hardness and thickness of the layers and kerf geometry because processing accuracy is determined by the geometry of the cut. Thus, is proposed a novel algorithm based on minimization of angle of kerf, for optimization a cutting process in abrasive water jet technology, which can be utilized for materials with different hardness in layers. Direct effect of optimization of cutting consist in increasing efficiency, dimensional precision, traverse velocity, and decreasing the amount of used abrasive garnet.

  5. Spectrum of the sound produced by a jet impinging on the gas-water interface of a supercavity

    Science.gov (United States)

    Foley, A. W.; Howe, M. S.; Brungart, T. A.

    2010-02-01

    An analysis is made of the sound generated by the impingement of an air jet on the gas-water interface of a supercavity. The water is in uniform low Mach number motion over the interface. The interface is rippled by the jet, which produces an unsteady surface force on the water that behaves as a dipole or monopole acoustic source, respectively, at high and low frequencies. In a first approximation the very large difference in the gas density and that of water implies that the surface force is similar to that occurring when a jet impinges on a rigid wall. Data from recent measurements by Foley (2009, Ph.D. Dissertation, Department of Mechanical Engineering, Boston University) of the frequency spectrum of the surface force produced by the impact of a turbulent jet on a wall are used to formulate an analytical representation of the spectrum and thence to predict the sound produced in water when the same jet impinges on the cavity interface. The prediction is used to estimate the characteristics of gas jet impingement noise for an experimental supercavitating vehicle in use at the Applied Research Laboratory of Penn State University.

  6. Numerical thermal analysis of water's boiling heat transfer based on a turbulent jet impingement on heated surface

    Science.gov (United States)

    Toghraie, D.

    2016-10-01

    In this study, a numerical method for simulation of flow boiling through subcooled jet on a hot surface with 800 °C has been presented. Volume fraction (VOF) has been used to simulate boiling heat transfer and investigation of the quench phenomena through fluid jet on a hot horizontal surface. Simulation has been done in a fixed Tsub=55 °C, Re=5000 to Re=50,000 and also in different Tsub =Tsat -Tf between 10 °C and 95 °C. The effect of fluid jet velocity and subcooled temperature on the rewetting temperature, wet zone propagation, cooling rate and maximum heat flux has been investigated. The results of this study show that by increasing the velocity of fluid jet of water, convective heat transfer coefficient at stagnation point increases. More ever, by decreasing the temperature of the fluid jet, convective heat transfer coefficient increases.

  7. [Evaluation of potential risks of abrasive water jet osteotomy in-vivo].

    Science.gov (United States)

    Kuhlmann, C; Pude, F; Bishup, C; Krömer, S; Kirsch, L; Andreae, A; Wacker, K; Schmolke, S

    2005-10-01

    Since the 80's the water jet scalpel is an established tool in some surgical fields. It is used in particular in visceral surgery for preparation of parenchymatous organs. By the addition of biocompatible abrasives, this technique is able to effectively machine hard biological tissues. Free defined cutting geometries can be realised in a non contact process. Therewith this method has crucial advantages compared to conventional osteotomy techniques and gives new impulses to the development in endoprosthetics and correction osteotomies of hollow bones. In the presented work the new developed abrasive water injection jet (AWIJ) was used the first time for in-vivo osteotomies. Aim of this study was the detection of potential thrombembolic effects and wash in effects of the cutting fluid. Hollow bones of the fore and hind leg of 20 house pigs were treated with the new cutting technique. Intraoperative documentation of relevant vital parameters was performed by a multi monitoring system. Thrombembolic effects during the osteotomy were detected by transthoracic Doppler ultrasonography and transesophagale echocardiography. The hollow bones were prepared in consideration of the vascularisation's protection especially in respect to the venous flow. Thrombembolic effects with temporary haemodynamic respectively respiratory consequences could be detected exclusively by using the so called "3-component jet", which consists of 90 vol % of air. The usage of an abrasive suspension enables the airfree dosing of dry soluable abrasives. Thrombembolic effects could not be monitored in this case. Intramedullary fluid in-wash effects as well as resulting electrolytic disorders could not be proven. For abrasive waterjet osteotomies with 3 component jet a relevant risk of thrombembolic effects could be shown. This knowledge has also to be considered for abdominal and neurosurgical applications in the future. Due to the usage of an abrasive suspension this risk can fully be avoided.

  8. The jet impact force of laser-induced bubble under the water-film with different thickness

    Science.gov (United States)

    Li, Beibei; Wang, Bingyang; Liu, Xiumei; He, Jie; Lu, Jian

    2015-05-01

    The effect of water-film on the laser-induced bubble was investigated by a piezoelectric ceramic transducer (PZT) sensor. Both of the collapse time and liquid-jet impact force of the bubble under the water-film were obtained, and the experiments were also completed in different laser energy. The collapse time increase with the thickness of the waterfilm, but the liquid-jet impact force decrease. We consider that the collapse time was affected by both of the rigid boundary and surface, and the increasing of the collapse time is the reason the decreasing of the liquid-jet impact force. The velocity of bubble wall is lower with the longer collapse time for the uniform bubbles energy, so the liquid-jet impact force is lower. For the other reasons, more laser energy would be absorbed by the thicker water-film, but the water was also splashed for the thinner water-film. So, for the thinner water-film, the bubble energy is higher, the liquidjet impact force is higher, but the maximal radius is smaller because of the splash process. In the other hand, both of the collapse time and the liquid-jet impact force are increase with the laser energy. These researches are useful for the laser processing under water.

  9. A focused liquid jet formed by a water hammer in a test tube

    CERN Document Server

    Kiyama, Akihito; Ando, Keita; Kameda, Masaharu

    2015-01-01

    We investigate motion of a gas-liquid interface in a test tube induced by a large acceleration via impulsive force. We conduct simple experiments in which the tube partially filled with a liquid falls under gravity and impacts a rigid floor. A curved gas-liquid interface inside the tube reverses and eventually forms an elongated jet (i.e. the so-called a focused jet). In our experiments, there arises either vibration of the interface or increment in the velocity of a liquid jet accompanied by the onset of cavitation in the liquid column. These phenomena cannot be explained by considering pressure impulse in a classical potential flow analysis, which does not account for finite speeds of sound as well as phase change. Here we model such water-hammer events as a result of one-dimensional pressure wave propagation and its interaction with boundaries through acoustic impedance mismatching. The method of characteristics is applied to describe pressure wave interactions and the subsequent cavitation. The proposed m...

  10. Thermal Investigation of Interaction between High-power CW-laser Radiation and a Water-jet

    Science.gov (United States)

    Brecher, Christian; Janssen, Henning; Eckert, Markus; Schmidt, Florian

    The technology of a water guided laser beam has been industrially established for micro machining. Pulsed laser radiation is guided via a water jet (diameter: 25-250 μm) using total internal reflection. Due to the cylindrical jet shape the depth of field increases to above 50 mm, enabling parallel kerfs compared to conventional laser systems. However higher material thicknesses and macro geometries cannot be machined economically viable due to low average laser powers. Fraunhofer IPT has successfully combined a high-power continuous-wave (CW) fiber laser (6 kW) and water jet technology. The main challenge of guiding high-power laser radiation in water is the energy transferred to the jet by absorption, decreasing its stability. A model of laser water interaction in the water jet has been developed and validated experimentally. Based on the results an upscaling of system technology to 30 kW is discussed, enabling a high potential in cutting challenging materials at high qualities and high speeds.

  11. WATER-JET CUTTING MACHINE NOW AVAILABLE FROM THE CERN RAW MATERIALS STORES

    CERN Document Server

    2007-01-01

    The CERN Raw Materials Stores has recently acquired a new water-jet cutting machine. The machine is capable of cutting all types and shapes of materials up to 70 mm in thickness, with an accuracy of +/- 0.1mm/m. For the time being, users requiring materials to be cut should supply drawings in DXF, DWG or IGES (AutoCad) file format. The machine will be operational as of 1st October 2007. The Stores Team Paulo Dos Santos FI-LS-MM 72308

  12. WATER-JET CUTTING MACHINE NOW AVAILABLE FROM THE CERN RAW MATERIALS STORES

    CERN Multimedia

    2007-01-01

    The CERN Raw Materials Stores has recently acquired a new water-jet cutting machine. The machine is capable of cutting all types and shapes of materials up to 70 mm in thickness, with an accuracy of +/- 0.1mm/m. For the time being, users requiring materials to be cut should supply drawings in DXF, DWG or IGES (AutoCad) file format. The machine will be operational as of 1st October 2007. The Stores Team Paulo Dos Santos FI-LS-MM 72308

  13. The measurement of abrasive particles velocities in the process of abrasive water jet generation

    Science.gov (United States)

    Zeleňák, Michal; Foldyna, Josef; Říha, Zdeněk

    2014-08-01

    An optimization of the design of the abrasive cutting head using the numerical simulation requires gathering as much information about processes occurring in the cutting head as possible. Detailed knowledge of velocities of abrasive particles in the process of abrasive water jet generation is vital for the verification of the numerical model. A method of measurement of abrasive particles at the exit of focusing tube using the FPIV technique was proposed and preliminary tests are described in the paper. Results of analysis of measured velocity fields are presented in the paper.

  14. Cut Front Geometry Characterization in Cutting Applications of Brass with Abrasive Water Jet

    Science.gov (United States)

    Akkurt, Adnan

    2010-06-01

    Abrasive water jet (AWJ) cutting is an advanced manufacturing process for machining hard to cut materials. In this study, brass-353 samples of different thicknesses were cut by AWJ using different feed rates to identify the relationships between depth of cut (material thickness), feed rate, and deflection of cutting edge geometry. The effects of material thickness on the AWJ cut surface roughness were investigated and discussed. Deflection of cutting edge geometry in AWJ cutting process was assessed. Cutting edge geometry was characterized by analyzing the surface properties of cut samples.

  15. Assessment of three turbulence model performances in predicting water jet flow plunging into a liquid pool

    Directory of Open Access Journals (Sweden)

    Zidouni Kendil Faiza

    2010-01-01

    Full Text Available The main purpose of the current study is to numerically investigate, through computational fluid dynamics modeling, a water jet injected vertically downward through a straight circular pipe into a water bath. The study also aims to obtain a better understanding of jet behavior, air entrainment and the dispersion of bubbles in the developing flow region. For these purposes, three dimensional air and water flows were modeled using the volume of fluid technique. The equations in question were formulated using the density and viscosity of a 'gas-liquid mixture', described in terms of the phase volume fraction. Three turbulence models with a high Reynolds number have been considered i. e. the standard k-e model, realizable k-e model, and Reynolds stress model. The predicted flow patterns for the realizable k-e model match well with experimental measurements found in available literature. Nevertheless, some discrepancies regarding velocity relaxation and turbulent momentum distribution in the pool are still observed for both the standard k-e and the Reynolds stress model.

  16. Particle-free semiconductor cutting using the water jet guided laser

    Science.gov (United States)

    Perrottet, Delphine; Spiegel, Akos; Wagner, Frank; Housh, Roy; Richerzhagen, Bernold; Manley, John

    2005-04-01

    For many years, wafer cutting has posed a challenge to laser-based cutting techniques because of the brittle nature of semiconductors and the exacting requirements for cleanliness. Since conventional laser cutting generates a strong heat-affected zone and a large amount of particles, abrasive sawing is currently the standard process for semiconductor wafer dicing. However, abrasive sawing can no longer fulfill the demands of new, emerging types of semiconductor devices like those based on thin wafers and compound semiconductors. New separation methods are investigated here. The water jet guided laser is a relatively recent technology that offers not only a significantly reduced heat-affected zone but also a cleaner wafer surface. This is due, first, to the water jet, which cools the material between the laser pulses and removes a significant amount of molten material generated by laser ablation. However, the system has recently been upgraded by adding a device that covers the entire wafer surface with a well-controlled thin water film throughout the cutting process. The few generated particles are thus kept in suspension and will not deposit on the wafer surface.

  17. Rain erosion of wind turbine blade coatings using discrete water jets: Effects of water cushioning, substrate geometry, impact distance, and coating properties

    DEFF Research Database (Denmark)

    Zhang, Shizhong; Dam-Johansen, Kim; Bernad, Pablo L.

    2015-01-01

    Rapid and reliable rain erosion screening of blade coatings for wind turbines is a strong need in the coatings industry. One possibility in this direction is the use of discrete water jets, where so-called jet slugs are impacted on a coating surface. Previous investigations have mapped...... the influence of water jet slug velocity and impact frequency. In the present work, the effects on coating erosion of water cushioning, substrate curvature, and water nozzle-coating distance were explored. The investigations showed that in some cases water cushioning (the presence of a liquid film...... on the coating surface prior to impact) influences the erosion. Contrary to this, substrate curvature and the water nozzle-coating distance (coatings, including tensile strength, flexibility...

  18. Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines: 1. Model calculation of the physical conditions in a jet exhaust

    Science.gov (United States)

    Platov, Yu. V.; Alpatov, V. V.; Klyushnikov, V. Yu.

    2014-01-01

    Model calculations have been performed for the temperature and pressure of combustion products in the jet exhaust of rocket engines of last stages of Proton, Molniya, and Start launchers operating in the upper atmosphere at altitudes above 120 km. It has been shown that the condensation of water vapor and carbon dioxide can begin at distances of 100-150 and 450-650 m away from the engine nozzle, respectively.

  19. The Research and Development of a Cavitating Water Jet Cleaning System for Removing Marine Growth and Fouling from Offshore Platform Structures.

    Science.gov (United States)

    1979-12-01

    AO-AO85 730 DAEOALEAN ASSOCIATES INC WOODBINE MD F/0 13/9 THE RESEARCH AND DEVELOPMENT OF A CAVITATING WATER JET CLEANING--TC(U) DEC 79 J T PARKER, W...REPORT THE RESEARCH AND DEVELOPMENT OF A CAVITATING WATER JET CLEANING SYSTEM FOR REMOVING MARINE GROWTH AND FOULING FROM OFFSHORE PLATFORM STRUCTURES...DEVELOPMENT OF A CAVITATING WATER JET CLEANING SYSTEM FOR REMOVING MARINE GROWTH AND FOULING FROM OFFSHORE PLATFORM STRUCTURES 1.0 INTRODUCTION Inspection of

  20. Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine

    Directory of Open Access Journals (Sweden)

    Drobek Christoph

    2015-09-01

    Full Text Available Particle Image Velocimetry (PIV measurements of a water-jet for water-assisted liposuction (WAL are carried out to investigate the distribution of velocity and therefore momentum and acting force on the human sub-cutaneous fat tissue. These results shall validate CFD simulations and force sensor measurements of the water-jet and support the development of a new WAL device that is able to harvest low volumes of fat tissue for regenerative medicine even gentler than regular WAL devices.

  1. Generation of ultra-fast cumulative water jets by sub-microsecond underwater electrical explosion of conical wire arrays

    Energy Technology Data Exchange (ETDEWEB)

    Shafer, D.; Gurovich, V. Tz.; Gleizer, S.; Gruzinsky, K.; Krasik, Ya. E. [Physics Department, Technion, Haifa 32000 (Israel)

    2015-12-15

    The results of experiments with underwater electrical explosion of modified conical arrays of copper and aluminum wires are presented. A pulsed generator producing a 550 kA-amplitude current with a 400 ns rise time was used in the explosion of the arrays. The array explosion generates water flows converging at the axis of the cone. This flow generates a fast-moving water jet with a velocity exceeding 1.8 × 10{sup 5 }cm/s, which was observed being ejected from the surface of the water covering the array. The positions of the water jet were measured by multiple-exposure fast framing imaging. In experiments, the apex angle of the array, the thickness of the water layer above the arrays, or the material of the wires was altered, which changed the resulting velocities and shapes of the emitted jets. A model that considers the converging stationary flow of a slightly compressible fluid is suggested. The velocities and shapes of the jets obtained by this model agree well with the experimentally measured jet velocities.

  2. Inline Array Jet Impingement Cooling Using Al2O3 / Water Nanofluid In A Plate Finned Electronic Heat Sink

    Directory of Open Access Journals (Sweden)

    R. Reji Kumar

    2016-07-01

    Full Text Available - Jet impingement cooling is a technique used for cooling the electronic systems. In this work, heat transfer and pressure drop characteristics of deionized water and Al2O3/water nanofluid in an electronic heat sink having aluminium plate fins and provision for jet impingement cooling have been studied. A novel heat sink contains two rows of plate fins of size 29mm x 24mm x 0.56mm. A thin plate having 110 holes of diameter 2.5 mm is used to produce number of jets. The plate is kept inside the heat sink in such a way that H/dn is 5.2 mm and adjacent jet spacing is 2mm. The overall dimension of the heat sink is 60x60x 65 mm. For this work we prepared a Al2O3/water nanofluid by dispersing specified quantity of nanoparticles in to deionized water by using a ultrasonic bath. Experiments were conducted under constant heat flux condition and the volume flow rate of the fluid was in the range of 1.315 to 2.778. It is found from the results that the nanofluid removes heat better than water in the jet impingement cooling with very low rise in pressure drop.

  3. Performance of Water Jet Cutting Cobalt-rich Crusts%水射流切削钴结壳性能研究

    Institute of Scientific and Technical Information of China (English)

    黄中华; 谢雅

    2011-01-01

    建立了水射流系统的动力学模型,通过仿真研究获取了水射流系统参数与水射流切削性能的作用规律.仿真结果表明:水射流的有效作业距离为水射流的等速区长度;水射流的工作压力越高,水射流的出口速度越大;喷嘴的轴向射流速度变化与围压无关.开展了水射流切削钴结壳模拟料性能实验研究.实验结果表明:水射流切削钴结壳模拟料时存在一个门槛压力,当水射流的压力小于5MPa时,水射流不能切削钴结壳模拟料;当水射流压力大于5MPa时,随着水射流压力的增大,水射流的切削能力快速增加;当喷距小于5mm时,水射流能够击穿钴结壳模拟料,随着喷距的增加,水射流的切削能力急剧下降.%Dynamic model of water jet system is established. With simulation research, the working rule of water jet system parameters and its cutting performance are obtained. Simulation results show that water jet effective working rangence is the length of water jet potential core; with the increasing of water jet pressure, water jet export speed increases correspondingly. Water jet axial velocity changing of nozzle is irrelevant with environmental pressure. Experimental study of water jet cutting cobalt-rich crusts simula- tion materials are carried out. Experimental results show that there is a threshold pressure during water jet cutting cobalt-rich crusts simulation materials. When water jet pressure is less than 5 MPa, water jet can" t cut cobalt-rich crusts simulation materials. When water jet pressure is greater than 5MPa, with the increasing of water jet pressure, water jet cutting ability increases quickly. When the working range is less than 5 mm, water jet can cut cobalt-rich crusts simulation materials. With the increasing of working range, water jet cutting ability decreases sharply.

  4. Code Development in Coupled PARCS/RELAP5 for Supercritical Water Reactor

    Directory of Open Access Journals (Sweden)

    Po Hu

    2014-01-01

    Full Text Available The new capability is added to the existing coupled code package PARCS/RELAP5, in order to analyze SCWR design under supercritical pressure with the separated water coolant and moderator channels. This expansion is carried out on both codes. In PARCS, modification is focused on extending the water property tables to supercritical pressure, modifying the variable mapping input file and related code module for processing thermal-hydraulic information from separated coolant/moderator channels, and modifying neutronics feedback module to deal with the separated coolant/moderator channels. In RELAP5, modification is focused on incorporating more accurate water properties near SCWR operation/transient pressure and temperature in the code. Confirming tests of the modifications is presented and the major analyzing results from the extended codes package are summarized.

  5. Portable mixed abrasive water jet equipment for rescue in high gas mine shaft

    Institute of Scientific and Technical Information of China (English)

    ZENG Rui; DU Chang-long; XU Rui; ZHAO Jing

    2011-01-01

    In order to rescue a trapped miner and clean out roadways quickly in a high gas mine shaft after a mining mishap, a special portable cold-cutting equipment is needed, the main technology parameters were calculated according to the advanced cold-cutting technology of high pressure abrasive water jet and the portable mixed abrasive water jet equipment (PAWE) was designed to meet the needs of emergency rescue in high gas mine shafts. Tested the PAWE in a high gas environment, and the result shows that the maximum cutting depth of solid iron pipe is 18 mm and the recoilforce of the sprayer is 28.9 N under the conditions that actual cutting pressure is 29 MPa, starting target distance is 10 mm, cutting speed is 180 mm/min and concentration of abrasive is 32%. The course of the experiment in the high gas environment was smooth and continuous, without any explosion. The PAWE is easy to move and operate, but the nozzle which was worn badly in the sprayer should be changed every 8 minutes.

  6. Endoscopic band ligation with a water-jet scope for the treatment of colonic diverticular hemorrhage.

    Science.gov (United States)

    Ishii, Naoki; Itoh, Toshiyuki; Uemura, Masayo; Maruyama, Masataka; Horiki, Noriyuki; Setoyama, Takeshi; Matsuda, Michitaka; Suzuki, Shoko; Iizuka, Yusuke; Fukuda, Katsuyuki; Fujita, Yoshiyuki

    2010-07-01

    Although lower gastrointestinal bleeding generally has a less severe course and stops spontaneously in most cases without therapeutic intervention, some patients require endoscopic, surgical, or angiographic treatment depending on the nature of the bleeding. We applied endoscopic band ligation (EBL) with a water-jet scope to bleeding colonic diverticula and evaluated the efficacy and safety of EBL retrospectively. Five consecutive patients were diagnosed as having colonic diverticular hemorrhage, and were treated with EBL at St Luke's International Hospital in Tokyo from June 2009 to August 2009. Comorbid diseases, usage of anti-platelet agents, hemoglobin level on admission, procedural time, complications such as perforation and abscess formation, and rebleeding after EBL were retrospectively evaluated. In all cases, EBL achieved successful immediate hemostasis without any procedural complications. In four of five cases, bleeding colonic diverticula were everted after EBL. The mean length of hospital stay after EBL was 5 days (range 4-8 days). No patient exhibited clinical evidence of further bleeding during the mean follow-up period of 3 months (range 2-4 months), and no further intervention was needed after EBL. EBL with a water-jet scope is considered to be a safe and effective endoscopic treatment for colonic diverticular hemorrhage.

  7. Radiant Energy Measurements from a Scaled Jet Engine Axisymmetric Exhaust Nozzle for a Baseline Code Validation Case

    Science.gov (United States)

    Baumeister, Joseph F.

    1994-01-01

    A non-flowing, electrically heated test rig was developed to verify computer codes that calculate radiant energy propagation from nozzle geometries that represent aircraft propulsion nozzle systems. Since there are a variety of analysis tools used to evaluate thermal radiation propagation from partially enclosed nozzle surfaces, an experimental benchmark test case was developed for code comparison. This paper briefly describes the nozzle test rig and the developed analytical nozzle geometry used to compare the experimental and predicted thermal radiation results. A major objective of this effort was to make available the experimental results and the analytical model in a format to facilitate conversion to existing computer code formats. For code validation purposes this nozzle geometry represents one validation case for one set of analysis conditions. Since each computer code has advantages and disadvantages based on scope, requirements, and desired accuracy, the usefulness of this single nozzle baseline validation case can be limited for some code comparisons.

  8. Analysis and Numerical Simulation on the Reduction Effect of Stress Waves Caused by Water Jet Slotting Near Blasting Source

    Directory of Open Access Journals (Sweden)

    Dengfeng Su

    2016-01-01

    Full Text Available As one of the most serious “side effects” of blast excavation, blast-induced vibration must be controlled for existing buildings and human beings. This paper proposes a method for blast-induced vibration reduction with water jet assistance according to the cutting characters of low-noised, environment-friendly water jet. The mechanism of vibration-isolation with water jet assistance was analyzed, and the stress wave energy attenuation models were established based on blasting theory and stress wave theory. Influence law on shock wave attenuation by vibration-isolation slot was studied by numerical simulation. Simulation results agree with the theoretical analysis roughly. The results of this study put forward a method for blast-induced vibration near blasting source and provide a certain theoretical basis.

  9. Comparative Study of Remote Fiber Laser and Water-Jet Guided Laser Cutting of Thin Metal Sheets

    Science.gov (United States)

    Hock, Klaus; Adelmann, Benedikt; Hellmann, Ralf

    This article presents a comparison between remote laser cutting with a fiber laser and water-jet guided laser cutting using a 532 nm solid state laser. Complex contours are processed in stainless steel and brass sheets (thickness ≤ 100 μm), respectively. Results for achievable quality and productivity as well as possible applications for both systems are shown and discussed. We sustained dross free cuts with almost no heat affected zone and small kerf width for the water-jet guided process, whereas small dross, notable heat affected zone and varying kerf width where observed for remote cutting. However, process times for the water-jet guided process where considerably higher than those for remote cutting.

  10. A study on practical use of underwater abrasive water jet cutting

    Science.gov (United States)

    Yamaguchi, Hitoshi; Demura, Kenji

    1993-09-01

    The practicality of underwater abrasive water jet cutting technology was studied in experiments. A study of abrasives in slurried form showed that optimum polymer concentration can be selected to suit underwater conditions. For the long-distance transport of slurry from the ocean surface to the ocean floor, a direct supply system by hose proved to be practical. This system takes advantage of the insolubility of the slurry in water due to a difference in specific gravity. For cutting thick steel plate at great ocean depths, a simulation with a pressurized container revealed the requirements for actual cutting. Confirmation of remote cutting operations will become the most important technology in field applications. Underwater sound vibration characteristics were found to change significantly in direct response to modifications in cutting conditions. This will be important basic data to develop an effective sensoring method.

  11. Experimental application of pulsed laser-induced water jet for endoscopic submucosal dissection: mechanical investigation and preliminary experiment in swine.

    Science.gov (United States)

    Sato, Chiaki; Nakano, Toru; Nakagawa, Atsuhiro; Yamada, Masato; Yamamoto, Hiroaki; Kamei, Takashi; Miyata, Go; Sato, Akira; Fujishima, Fumiyoshi; Nakai, Masaaki; Niinomi, Mitsuo; Takayama, Kazuyoshi; Tominaga, Teiji; Satomi, Susumu

    2013-05-01

    A current drawback of endoscopic submucosal dissection (ESD) for early-stage gastrointestinal tumors is the lack of instruments that can safely assist with this procedure. We have developed a pulsed jet device that can be incorporated into a gastrointestinal endoscope. Here, we investigated the mechanical profile of the pulsed jet device and demonstrated the usefulness of this instrument in esophageal ESD in swine. The device comprises a 5-Fr catheter, a 14-mm long stainless steel tube for generating the pulsed water jet, a nozzle and an optical quartz fiber. The pulsed water jet was generated at pulse rates of 3 Hz by irradiating the physiological saline (4°C) within the stainless steel tube with an holmium-doped yttrium-aluminum-garnet (Ho:YAG) laser at 1.1 J/pulse. Mechanical characteristics were evaluated using a force meter. The device was used only for the part of submucosal dissection in the swine ESD model. Tissues removed using the pulsed jet device and a conventional electrocautery device, and the esophagus, were histologically examined to assess thermal damage. The peak impact force was observed at a stand-off distance of 40 mm (1.1 J/pulse). ESD using the pulsed jet device was successful, as the tissue specimens showed precise dissection of the submucosal layer. The extent of thermal injury was significantly lower in the dissected bed using the pulsed jet device. The results showed that the present endoscopic pulsed jet system is a useful alternative for a safe ESD with minimum tissue injury. © 2012 The Authors. Digestive Endoscopy © 2012 Japan Gastroenterological Endoscopy Society.

  12. Water jet dissection in neurosurgery: an update after 208 procedures with special reference to surgical technique and complications.

    Science.gov (United States)

    Keiner, Doerthe; Gaab, Michael R; Backhaus, Vanessa; Piek, Juergen; Oertel, Joachim

    2010-12-01

    Water jet dissection represents a promising technique for precise brain tissue dissection with preservation of blood vessels. In the past, the water jet dissector has been used for various pathologies. A detailed report of the surgical technique is lacking. The authors present their results after 208 procedures with a special focus on surgical technique, intraoperative suitability, advantages, and disadvantages. Between March 1997 and April 2009, 208 patients with various intracranial neurosurgical pathologies were operated on with the water jet dissector. Handling of the device and its usefulness and extent of application were assessed. The pressures encountered, potential risks, and complications were documented. The patients were followed 1 to 24 months postoperatively. A detailed presentation of the surgical technique is given. Differences and limitations of the water jet dissection device in the various pathologies were evaluated. The water jet dissector was intensively used in 127 procedures (61.1%), intermittently used in 56 procedures (26.9%), and scarcely used in 25 procedures (12%). The device was considered to be very helpful in 166 procedures (79.8%) and helpful to some extent in 33 procedures (15.9%). In 8 (3.8%) procedures, it was not helpful, and in 1 procedure (0.5%), the usefulness was not documented by the surgeon. The water jet dissector can be applied easily and very safely. Precise tissue dissection with preservation of blood vessels and no greater risk of complications are possible. However, the clinical consequences of the described qualities need to be demonstrated in a randomized clinical trial.

  13. WATER-FILLING SPACE-TIME CODE IN CORRELATED FLAT RAYLEIGH FADING MISO CHANNELS

    Institute of Scientific and Technical Information of China (English)

    Cheng Jian; Chen Ming; Cheng Shixin

    2003-01-01

    In this paper, STC with water-filling transmit power distribution in MISO systemis proposed when the partial channel information feedback is possible, for example, at slow fadingscenario. The performances of the water-filling STC including water-filling STTC and water-filling STBC are analyzed. Performance comparison of the Ungerboeck's 2/3 trellis coded 8PSKmodulated 2-STBC and 2-STTCs with QPSK is given out in different channel correlation.

  14. Laboratory Scale Study of Activated Sludge Process in Jet Loop Reactor for Waste WaterTreatment

    Directory of Open Access Journals (Sweden)

    M. S. Patil

    2014-03-01

    Full Text Available The present study was undertaken to evaluate the feasibility of Activated Sludge Process (ASP for the treatment of synthetic wastewater and to develop a simple design criteria under local conditions.A laboratory scale Compact jet loop reactor model comprising of an aeration tank and final clarifier was used for this purpose.Settled synthetic wastewater was used as influent to the aeration tank. The Chemical Oxygen Demand (COD of the influent and effluent was measured to find process efficiency at various mixed liquorvolatile suspended solids (MLVSS and hydraulic retention time (θ. The results of the studydemonstrated that an efficiency of above 95% could be obtained for COD if the ASP is operated atan MLVSS concentration of 3000 mg/L keeping an aeration time of 1 hour.In the present investigation the preliminary studies were carried out in a lab scale Jet loop reactor made of glass. Synthetic waste water having a composition of 1000 mg/L mixed with other nutrients such as Urea, Primary and secondary Potassium phosphates, Magnesium sulfate, Iron chloriderequired for the bacteria was prepared in the laboratory and reduction in COD and the increase inSuspended Solids (SSand the Sludge Volume Index (SVI were determined.

  15. A `Water Spout' Maser Jet in S235AB-MIR

    CERN Document Server

    Burns, Ross A; Handa, Toshihiro; Omodaka, Toshihiro; Nakagawa, Akiharu; Nagayama, Takumi; Ueno, Yuji

    2015-01-01

    We report on annual parallax and proper motion observations of H2O masers in S235AB-MIR, which is a massive young stellar object in the Perseus Arm. Using multi-epoch VLBI astrometry we measured a parallax of pi = 0.63 +- 0.03 mas, corresponding to a trigonometric distance of D = 1.56+-0.09 kpc, and source proper motion of ( u alpha cos d , u d) = (0.79 +- 0.12, -2.41 +- 0.14) mas/yr. Water masers trace a jet of diameter 15 au which exhibits a definite radial velocity gradient perpendicular to its axis. 3D maser kinematics were well modelled by a rotating cylinder with physical parameters: v_out = 45+-2 km/s, v_rot = 22+-3 km/s, i = 12+-2 degrees, which are the outflow velocity, tangential rotation velocity and line-of-sight inclination, respectively. One maser feature exhibited steady acceleration which may be related to the jet rotation. During our 15 month VLBI programme there were three `maser burst' events caught `in the act' which were caused by the overlapping of masers along the line of sight.

  16. Do Water Fountain Jets Really Indicate the Onset of the Morphological Metamorphosis of Circumstellar Envelopes?

    CERN Document Server

    Yung, Bosco H K; Hsia, Chih-Hao; Imai, Hiroshi

    2016-01-01

    The small-scale bipolar jets having short dynamical ages from "water fountain (WF)" sources are regarded as an indication of the onset of circumstellar envelope morphological metamorphosis of intermediate-mass stars. Such process usually happens at the end of the asymptotic giant branch (AGB) phase. However, recent studies found that WFs could be AGB stars or even early planetary nebulae. This fact prompted the idea that WFs may not necessarily be objects at the beginning of the morphological transition process. In the present work, we show that WFs could have different envelope morphologies by studying their spectral energy distribution profiles. Some WFs have spherical envelopes that resembles usual AGB stars, while others have aspherical envelopes which are more common to post-AGB stars. The results imply that WFs may not represent the earliest stage of the morphological metamorphosis. We further argue that the dynamical age of a WF jet, which can be calculated from maser proper motions, may not be the rea...

  17. Water consumption footprint and land requirements of large-scale alternative diesel and jet fuel production.

    Science.gov (United States)

    Staples, Mark D; Olcay, Hakan; Malina, Robert; Trivedi, Parthsarathi; Pearlson, Matthew N; Strzepek, Kenneth; Paltsev, Sergey V; Wollersheim, Christoph; Barrett, Steven R H

    2013-01-01

    Middle distillate (MD) transportation fuels, including diesel and jet fuel, make up almost 30% of liquid fuel consumption in the United States. Alternative drop-in MD and biodiesel could potentially reduce dependence on crude oil and the greenhouse gas intensity of transportation. However, the water and land resource requirements of these novel fuel production technologies must be better understood. This analysis quantifies the lifecycle green and blue water consumption footprints of producing: MD from conventional crude oil; Fischer-Tropsch MD from natural gas and coal; fermentation and advanced fermentation MD from biomass; and hydroprocessed esters and fatty acids MD and biodiesel from oilseed crops, throughout the contiguous United States. We find that FT MD and alternative MD derived from rainfed biomass have lifecycle blue water consumption footprints of 1.6 to 20.1 Lwater/LMD, comparable to conventional MD, which ranges between 4.1 and 7.4 Lwater/LMD. Alternative MD derived from irrigated biomass has a lifecycle blue water consumption footprint potentially several orders of magnitude larger, between 2.7 and 22 600 Lwater/LMD. Alternative MD derived from biomass has a lifecycle green water consumption footprint between 1.1 and 19 200 Lwater/LMD. Results are disaggregated to characterize the relationship between geo-spatial location and lifecycle water consumption footprint. We also quantify the trade-offs between blue water consumption footprint and areal MD productivity, which ranges from 490 to 4200 LMD/ha, under assumptions of rainfed and irrigated biomass cultivation. Finally, we show that if biomass cultivation for alternative MD is irrigated, the ratio of the increase in areal MD productivity to the increase in blue water consumption footprint is a function of geo-spatial location and feedstock-to-fuel production pathway.

  18. The National Shipbuilding Research Origran, Oriceedubgs if tge REAPS Technical Symposium. Paper No. 2e: Application of Water Jet Technology to Shipbuilding

    Science.gov (United States)

    1977-06-01

    Proceedings of the REAPS Technical Symposium. Paper No. 23: Applications of Water Jet Technology to Shipbuilding. The use of hydraulic techniques for...ship hull cleaning/surface preparation and cutting of primary metals has received considerable attention in recent years. Water jet cleaning of ship

  19. Photoelectron spectroscopy of liquid water, some alcohols, and pure nonane in free micro jets

    Science.gov (United States)

    Faubel, Manfred; Steiner, Björn; Toennies, J. Peter

    1997-06-01

    The recently developed technique of accessing volatile liquids in a high vacuum environment by using a very thin liquid jet is implemented to carry out the first measurements of photoelectron spectra of pure liquid water, methanol, ethanol, 1-propanol, 1-butanol, and benzyl alcohol as well as of liquid n-nonane. The apparatus, which consists of a commercial hemispherical (10 cm mean radius) electron analyzer and a hollow cathode discharge He I light source is described in detail and the problems of the sampling of the photoelectrons in such an environment are discussed. For water and most of the alcohols up to six different electronic bands could be resolved. The spectra of 1-butanol and n-nonane show two weakly discernable peaks from which the threshold ionization potential could be determined. A deconvolution of the photoelectron spectra is used to extract ionization potentials of individual molecular bands of molecules near the surface of the liquid and shifts of the order of 1 eV compared to the gas phase are observed. A molecular orientation for water molecules at the surface of liquid water is inferred from a comparison of the relative band strengths with the gas phase. Similar effects are also observed for some of the alcohols. The results are discussed in terms of a simple "Born-solvation" model.

  20. EXPERIMENTAL STUDY ON THE VORTEX FORMATION AND ENTRA-INMENT CHARACTERISTICS FOR A ROUND TRANSVERSE JET IN SHALLOW WATER

    Institute of Scientific and Technical Information of China (English)

    FAN Jing-yu; ZHANG Yan; WANG Dao-zeng

    2009-01-01

    The vortex formation and entrainment characteristics for a round transverse jet in shallow water were experimentally investigated by means of a combination of LIF flow visualization and PIV measurement. A scarf vortex wrapped around the main body of the jet is formed in the near-wall region due to the interaction between the resulting wall jet and sufficiently shallow crossflow, with some more or less unsteady flow properties and with spreading ranges as functions of both the velocity ratio and the water depth within the near field. The entrainment of the ambient crossflow fluid into the jet main body is closely associated with the time-evolving features of the shear layer between the jet and surrounding fluid as well as the induced vortical structures near the wall. In the case of slight impingement upon the wall, the interaction between the jet shear layer and the weak, unstable scarf vortex gives rise to an appreciable local entrainment enhancement, confined in the near-wall region in the vicinity of the stagnation point. While in the case of intense impingement upon the wall, the well-organized and stable scarf vortex gives rise to a greatly enhanced entrainment and a greatly increased lateral spreading rate nearly throughout the overall near field as compared to the conventional wall jet. In addition, the entrainment of the ambient crossflow fluid by the scarf vortex in this case occurs largely on the surface of the unique spiral roller structure by itself due to the presence of smaller and unorganized eddies, and accordingly the scarf vortex is likely to keep its spiral roller structure steadily to a relatively great downstream distance within the near field.

  1. Application of thermophilic enzymes and water jet system to cassava pulp.

    Science.gov (United States)

    Chaikaew, Siriporn; Maeno, Yuka; Visessanguan, Wonnop; Ogura, Kota; Sugino, Gaku; Lee, Seung-Hwan; Ishikawa, Kazuhiko

    2012-12-01

    Co-production of fermentable sugars and nanofibrillated cellulose from cassava pulp was achieved by the combination of thermophilic enzymes (endoglucanase, β-glucosidase, and α-amylase) and a new atomization system (Star Burst System; SBS), which employs opposing water jets. The SBS represents a key technology for providing cellulose nanofibers and improving the enzymatic saccharification of cassava pulp. Depending on the enzymes used, the production of glucose from cassava pulp treated with the SBS was 1.2- to 2.5-fold higher than that from pulp not treated with the SBS. Nanofibrillated cellulose with the gel-like property in suspension was produced (yield was over 90%) by α-amylase treatment, which completely released trapped starch granules from the fibrous cell wall structure of cassava pulp pretreated with the SBS. The SBS provides an environmentally low-impact pretreatment system for processing biomass material into value-added products. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Process parameters effect on material removal mechanism and cut quality of abrasive water jet machining

    Directory of Open Access Journals (Sweden)

    Janković P.

    2013-01-01

    Full Text Available The process of the abrasive water jet cutting of materials, supported by the theories of fluid mechanics, abrasive wear and damage mechanics, is a high-tech technologies that provides unique capabilities compared to conventional machining processes. This paper, along the theoretical derivations, provides original contributions in the form of mathematical models of the quantity of the cut surface damage, expressed by the values of cut surface roughness. The particular part of this paper deal with the results of the original experimental research. The research aim was connected with the demands of industry, i.e. the end user. Having in mind that the conventional machining processes are not only lagging behind in terms of quality of cut, or even some requests are not able to meet, but with the advent of composite materials were not able to machine them, because they occurred unacceptable damage (mechanical damage or delamination, fiber pull-out, burning, frayed edges.

  3. Feasibility Study on IPMC Actuated Contractile Water Jet Thruster Body Contraction

    Directory of Open Access Journals (Sweden)

    Shaari Muhammad Farid

    2016-01-01

    Full Text Available This research was conducted to investigate the feasibility of Ionic Polymer Metal Composite (IPMC as the actuator for Contractile Water Jet Thruster (CWJT. The thrust that generated from the accelerated volume of ejected fluid depends on the IPMC actuator contraction performance. During this investigation, the variation of contraction frequency and nozzle aperture influence on the body deformation was carried out. The results of the experiments exhibit that the body contraction decreased tremendously from 0.05 Hz to 0.15 Hz. The body contraction has no apparent decrement for more than 0.15 Hz of contraction frequency. Besides, larger nozzle aperture has relatively more body contraction than smaller nozzle aperture. These results show that the fixed actuation force and the contraction frequency have a significant influence on the CWJT body contraction.

  4. An acoustic emission study of cutting bauxite refractory ceramics by abrasive water jets

    Science.gov (United States)

    Momber, A. W.; Mohan, R. S.; Kovacevic, R.

    1999-08-01

    This article discusses the material removal process in bauxite refractory ceramics cut by abrasive water jets. Several parameters of the process were changed during the experiments. The experiments were monitored online by the acoustic emission (AE) technique. It was found that AE signals are able to sense the material removal process as well as the machining performances very reliably. Unsteady material removal mode consisting of matrix removal and intergranular fracture was very well represented in the AE signals by an unsteady time dependent signal type characterized by burst emissions and a frequency domain signal associated with a twin-peak shape. The particular characteristics of the signal depend on the energy involved in the process.

  5. Simulation of abrasive water jet cutting process: Part 2. Cellular automata approach

    Science.gov (United States)

    Orbanic, Henri; Junkar, Mihael

    2004-11-01

    A new two-dimensional cellular automata (CA) model for the simulation of the abrasive water jet (AWJ) cutting process is presented. The CA calculates the shape of the cutting front, which can be used as an estimation of the surface quality. The cutting front is formed based on material removal rules and AWJ propagation rules. The material removal rule calculates when a particular part of the material will be removed with regard to the energy of AWJ. The AWJ propagation rule calculates the distribution of AWJ energy through CA by using a weighted average. The modelling with CA also provides a visual narrative of the moving of the cutting front, which is hard to observe in real process. The algorithm is fast and has been successfully tested in comparison to cutting fronts obtained with cutting experiments of aluminium alloy.

  6. Resistance of cyanobacterial fouling on architectural paint films to cleaning by water jet.

    Science.gov (United States)

    Shirakawa, Marcia Aiko; Loh, Kai; John, Vanderley Moacir; Gaylarde, Christine Claire

    2012-04-01

    Mortar panels painted with three different white acrylic coatings were exposed to the environment in urban (São Paulo) and rural (Pirassununga) sites in Brazil for 7 years. After this time, all panels were almost equally discoloured, and paint detachment was observed to only a small degree. The biofilms were composed mainly of cyanobacteria and filamentous fungi, principal genera being Gloeocapsa and Chroococcidiopsis of the cyanobacteria, and Cladosporium and Alternaria of the fungi. Two of the three paints in Pirassununga became covered by a pink film that contained red-encapsulated Gloeocapsa and clay particles. The third, an 800% elastomeric matt formulation, became discoloured with a grey, only slightly pink, film, although the same cyanobacteria were present. The levels of paint detachments from all films in both locations were low, with rating range of 0-1 of a maximum 5 (100% detachment). After high-pressure water jetting, paint detachments increased at both locations, up to 2 in Pirassununga and 3 in São Paulo. Discoloration decreased; L*A*B* analysis of surface discoloration showed that ΔE (alteration in colour from the original paint film) changed from 28-39 before cleaning to 13-16 afterwards. The pink coloration was not entirely removed from Pirassununga samples, suggesting that cyanobacterial cells are difficult to detach, and microscopic analysis of the biofilms confirmed that Gloeocapsa was still present as the principal contaminant on all surfaces, with Chroococcidiopsis being present as the second most common. Almost no fungi were detected after water jet application.

  7. Decontamination methods using a dental water jet and dental floss for microthreaded implant fixtures in regenerative periimplantitis treatment.

    Science.gov (United States)

    Park, Shin-Young; Kim, Kyoung-Hwa; Shin, Seung-Yun; Koo, Ki-Tae; Lee, Yong-Moo; Chung, Chong-Pyoung; Seol, Yang-Jo

    2015-06-01

    This study evaluated decontamination methods using a dental water jet and dental floss on microthreaded implants for regenerative periimplantitis therapy. In 6 beagle dogs, experimental periimplantitis was induced, and decontamination procedures, including manual saline irrigation (control group), saline irrigation using a dental water jet (group 1) and saline irrigation using a dental water jet with dental flossing (group 2), were performed. After in situ decontamination procedures, some of the implant fixtures (n = 4 per group) were retrieved for analysis by SEM, whereas other fixtures (n = 4 per group) underwent regenerative therapy. After 3 months of healing, the animals were killed. The SEM examination indicated that decontamination of the implant surfaces was the most effective in group 2, with no changes in implant surface morphology. The histological examination also revealed that group 2 achieved significantly greater amounts of newly formed bone (6.75 ± 2.19 mm; P = 0.018), reosseointegration (1.88 ± 1.79 mm; P = 0.038), and vertical bone fill (26.69 ± 18.42%; P = 0.039). Decontamination using a dental water jet and dental floss on microthreaded implants showed positive mechanical debridement effects and positive bone regeneration effects.

  8. Water-jet Propulsion with Positive Displacement Pump%正排量泵喷水推进技术

    Institute of Scientific and Technical Information of China (English)

    杨友胜; 朱玉泉; 罗小辉

    2011-01-01

    喷水推进是一种高性能的船舶推进方式.针对当前船舶推进器存在的问题,介绍了一种新型以正排量泵为核心的喷水推进方式,比较分析了正/负排量泵喷水推进两者的优缺点,得出正排量泵喷泵喷是一种能进一步改善船只性能的推进技术.%Water-jet propulsion is a high performance propulsion method. Regarding the current problems in ship propulsion appliances, a new type of water-jet propulsion is introduced, which uses positive displacement (PD) pump as power unit. A comparative study is made between the positive and negative displacement (ND) pump water-jet propulsions. The results show that the PD pump water-jet propulsion can further improves the performance ofwatercraft.

  9. Studies on supercritical water reactor fuel assemblies using the sub-channel code COBRA-EN

    Energy Technology Data Exchange (ETDEWEB)

    Ammirabile, Luca, E-mail: luca.ammirabile@ec.europa.e [European Commission, JRC, Institute for Energy, Westerduinweg 3, 1755 LE Petten (Netherlands)

    2010-10-15

    In the Generation IV International Forum (GIF) program, the supercritical water reactor (SCWR) concept is among the six innovative reactor types selected for development in the near future. In principle the higher efficiency and better economics make the SCWR concept competitive with the current reactor design. Due to different technical challenges that, however exist, fuel assembly design represents a crucial aspect for the success of this concept. In particular large density variations, low moderation, heat transfer enhancement and deterioration have a strong effect on the core design parameters. Only a few computational tools are currently able to perform sub-channel thermal-hydraulic analysis under supercritical water conditions. At JRC-IE the existing sub-channel code COBRA-EN has been improved to work above the critical pressure of water. The water properties package of the IAPWS Industrial Formulation 1997 was integrated in COBRA-EN to compute the Thermodynamic Properties of Water and Steam. New heat transfer and pressure drop correlations more indicated for the supercritical region of water have also been incorporated in the code. As part of the efforts to appraise the new code capabilities, a code assessment was carried out on the hexagonal fuel assembly of a fast supercritical water reactor. COBRA-EN was also applied in combination with the neutronic code MCNP to investigate on the use of hydride fuel in the HPLWR supercritical water fuel assembly. The results showed that COBRA-EN was able to reproduce the results of similar studies with acceptable accuracy. Future activities will focus on the validation of the code against experimental data and the implementation of new features (counter-current moderator channel, wall, and wire-wrap models).

  10. Structure Optimization and Numerical Simulation of Nozzle for High Pressure Water Jetting

    Directory of Open Access Journals (Sweden)

    Shuce Zhang

    2015-01-01

    Full Text Available Three kinds of nozzles normally used in industrial production are numerically simulated, and the structure of nozzle with the best jetting performance out of the three nozzles is optimized. The R90 nozzle displays the most optimal jetting properties, including the smooth transition of the nozzle’s inner surface. Simulation results of all sample nozzles in this study show that the helix nozzle ultimately displays the best jetting performance. Jetting velocity magnitude along Y and Z coordinates is not symmetrical for the helix nozzle. Compared to simply changing the jetting angle, revolving the jet issued from the helix nozzle creates a grinding wheel on the cleaning surface, which makes not only an impact effect but also a shearing action on the cleaning object. This particular shearing action improves the cleaning process overall and forms a wider, effective cleaning range, thus obtaining a broader jet width.

  11. Effects of air transient spark discharge and helium plasma jet on water, bacteria, cells, and biomolecules.

    Science.gov (United States)

    Hensel, Karol; Kučerová, Katarína; Tarabová, Barbora; Janda, Mário; Machala, Zdenko; Sano, Kaori; Mihai, Cosmin Teodor; Ciorpac, Mitică; Gorgan, Lucian Dragos; Jijie, Roxana; Pohoata, Valentin; Topala, Ionut

    2015-06-06

    Atmospheric pressure DC-driven self-pulsing transient spark (TS) discharge operated in air and pulse-driven dielectric barrier discharge plasma jet (PJ) operated in helium in contact with water solutions were used for inducing chemical effects in water solutions, and the treatment of bacteria (Escherichia coli), mammalian cells (Vero line normal cells, HeLa line cancerous cells), deoxyribonucleic acid (dsDNA), and protein (bovine serum albumin). Two different methods of water solution supply were used in the TS: water electrode system and water spray system. The effects of both TS systems and the PJ were compared, as well as a direct exposure of the solution to the discharge with an indirect exposure to the discharge activated gas flow. The chemical analysis of water solutions was performed by using colorimetric methods of UV-VIS absorption spectrophotometry. The bactericidal effects of the discharges on bacteria were evaluated by standard microbiological plate count method. Viability, apoptosis and cell cycle were assessed in normal and cancerous cells. Viability of cells was evaluated by trypan blue exclusion test, apoptosis by Annexin V-FITC/propidium iodide assay, and cell cycle progression by propidium iodide/RNase test. The effect of the discharges on deoxyribonucleic acid and protein were evaluated by fluorescence and UV absorption spectroscopy. The results of bacterial and mammalian cell viability, apoptosis, and cell cycle clearly show that cold plasma can inactivate bacteria and selectively target cancerous cells, which is very important for possible future development of new plasma therapeutic strategies in biomedicine. The authors found that all investigated bio-effects were stronger with the air TS discharge than with the He PJ, even in indirect exposure.

  12. 水射流冲击压力最佳喷距数值仿真及试验研究%Numerical Simulation and Experimental Research on the Best Jet Distances of Water Jet Impact Force

    Institute of Scientific and Technical Information of China (English)

    叶建友; 吕彦明

    2014-01-01

    基于水射流冲击模型,应用Fluent流体分析软件对喷嘴射流冲击力进行数值仿真,得出不同喷距对射流冲击压力的影响。结果表明:在低压连续水射流条件下,出口直径为2 mm的喷嘴在喷距为50 mm时产生的射流冲击压力最大;并通过实验验证射流仿真模型的正确性和有效性。%Based on water jet impact model,the jet impact numerical simulation was carried out by Fluent. The content include the effect of different jet distances influence on the jet impact pressure. The result shows that in the low pressure continuous water jet ,the jet impact pressure maximum when the nozzle diameter is 2 mm and the jet distances is 50 mm. Finally ,the validity and effectiveness of the jet simulation model were verified.

  13. Recent JET experiments on Alfven eigenmodes with intermediate toroidal mode numbers: measurements and modelling of n=3 toroidal Alfven eigenmodes with the TAEFL code

    Energy Technology Data Exchange (ETDEWEB)

    Testa, D. [CRPP, Switzerland; Spong, Donald A [ORNL; Panis, T. [CRPP, Switzerland; Blanchard, P. [CRPP, Switzerland; Fasoli, A. [CRPP, Switzerland

    2011-01-01

    This paper reports the results of recent experiments performed on the JET tokamak on Alfven eigenmodes (AEs) with toroidal mode number (n) in the range n = 3-15. The stability properties of these medium-n AEs are investigated experimentally using a new set of compact in-vessel antennas, providing a direct and real-time measurement of the frequency, damping rate and amplitude for each individual toroidal mode number. We report here the quantitative analysis of the measurements of the damping rate for stable n = 3 toroidal AEs as a function of the edge plasma elongation, and the theoretical analysis of these data with the TAEFL code. The TAEFL results are in excellent qualitative agreement with the measurements, reproducing well the experimental scaling of increasing damping rate versus increasing edge elongation, and in many cases are also quantitatively correct, with a difference with respect to the measurements below 30%, particularly for magnetic configurations that have a larger edge magnetic shear.

  14. Application of high-pressure water jet technology and the theory of rock burst control in roadway

    Institute of Scientific and Technical Information of China (English)

    Yang Zengqiang; Dou Linming; Liu Chang; Xu Mengtang; Lei Zhen; Yao Yahu

    2016-01-01

    This paper puts forward using high-pressure water jet technology to control rock burst in roadway, and analyzes the theory of controlling rock burst in roadway by the weak structure zone model. The weak structure zone is formed by using high-pressure water jet to cut the coal wall in a continuous and rota-tional way. In order to study the influence law of weak structure zone in surrounding rock, this paper numerically analyzed the influence law of weak structure zone, and the disturbance law of coal wall and floor under dynamic and static combined load. The results show that when the distance between high-pressure water jet drillings is 3 m and the diameter of drilling is 300 mm, continuous stress super-position zone can be formed. The weak structure zone can transfer and reduce the concentrated static load in surrounding rock, and then form distressed zone. The longer the high-pressure water jet drilling is, the larger the distressed zone is. The stress change and displacement change of non-distressed zone in coal wall and floor are significantly greater than that of distressed zone under dynamic and static com-bined load. And it shows that the distressed zone can effectively control rock burst in roadway under dynamic and static combined load. High-pressure water jet technology was applied in the haulage gate of 250203 working face in Yanbei Coal Mine, and had gained good effect. The study conclusions provide theoretical foundation and a new guidance for controlling rock burst in roadway.

  15. Rapid manufacturing of SiC molds with micro-sized holes using abrasive water jet

    Institute of Scientific and Technical Information of China (English)

    Bo-Sung SHIN; Kang-Su PARK; Yeon-Kyoung BAHK; Sun-Ki PARK; Jung-Han LEE; Jeung-Sang GO; Myung-Chang KANG; Chae-Moon LEE

    2009-01-01

    Silicon carbide (SIC) is highly wear resistant with good mechanical properties, including high temperature strength, excellent chemical resistance, and high thermal conductivity and thermal shock resistance. SiC molds, which can be produced with diverse microstructural features, are now widely used in glass molding owing to their excellent characteristics, and also have potential applicability in IT industries. SiC molds are traditionally fabricated by silicon micromachining or dicing. The fabrication cost of silicon micromachining is very high, however, because several expensive masks are needed. Furthermore, the fabrication time is very long. Meanwhile, it is difficult to make micro-patterned molds with arbitrary shapes using dicing saws. Abrasive water jet (AWJ) is widely applied to cut and drill very brittle, soft and fibrous materials. It offers high energy density, the absence of a heat affected zone(HAZ), high performance, and an environment friendly process. In spite of these advantages, micro-hole drilling via conventional AWJ processing suffers from notable shortcomings. We proposed a new abrasive supplying method of AWJ. The proposed method reduces frosting phenomena, and provides micro-machining of AWJ. The characteristics of a hole machined was investigated by the proposed AWJ process according to the ratio of water and abrasives. With the optimal experimental conditions, 3 × 3 array SiC molds with the diameter of 700 μm and depth of 900 μm were successfully manufactured.

  16. Fluid-Solid Interactive Methodology for Prognosis of Passenger Jet Structural Damage in Water Crash Landing

    Science.gov (United States)

    Bayandor, Javid

    2010-11-01

    Today, crashworthiness studies constitute a major part of modern aerospace design and certification processes. Of important consideration is the assessment of structural damage tolerance in terms of the extent of progressive damage and failure caused by aircraft emergency ditching on soft terrain or on water. Although a certification requirement, full scale crash landings are rarely tested using fully functional prototypes due to their high associated costs. This constraint makes it difficult for all crashworthy features of the design to be identified and fine-tuned before the commencement of the manufacturing phase. The current study presents aspects of a numerical methodology that can drastically subside the dependency of the certification assessments to full scale field trials. Interactive, fully nonlinear, solid-structure and fluid- structure analyses have been proposed using coupled Lagrangian- Eulerian and independent meshless Lagrangian approaches that run on a combined finite element-computational fluid dynamics platform. Detailed analysis of a key landing scenario pertaining to a large passenger jet will be provided to determine the relevance and accuracy of the proposed method. The work further identifies state-of-the-art computational approaches for modeling fluid-solid interactive systems that can help improve aircraft structural responses to soft impact and water ditching.

  17. The condensation of steam from steam-water mixture on water jets at high pressure

    Science.gov (United States)

    Somova, E. V.; Kisina, V. I.; Shvarts, A. L.; Kolbasnikov, A. V.; Kanishchev, V. P.

    2009-01-01

    A physical model for condensation of steam in water flow at high pressure is developed, and analytical dependences for calculating heat transfer are obtained, in particular as applied to the operation of a direct-contact feedwater heater for a new-generation reactor plant with lead coolant.

  18. Heat transfer coefficient distribution over the inconel plate cooled from high temperature by the array of water jets

    Science.gov (United States)

    Malinowski, Z.; Telejko, T.; Cebo-Rudnicka, A.; Szajding, A.; Rywotycki, M.; Hadała, B.

    2016-09-01

    The industrial rolling mills are equipped with systems for controlled water cooling of hot steel products. A cooling rate affects the final mechanical properties of steel which are strongly dependent on microstructure evolution processes. In case of water jets cooling the heat transfer boundary condition can be defined by the heat transfer coefficient. In the present study one and three dimensional heat conduction models have been employed in the inverse solution to heat transfer coefficient. The inconel plate has been heated to about 900oC and then cooled by one, two and six water jets. The plate temperature has been measured by 30 thermocouples. The heat transfer coefficient distributions at plate surface have been determined in time of cooling.

  19. Water Fountains in the Sky: Streaming Water Jets from Aging Star Provide Clues to Planetary-Nebula Formation

    Science.gov (United States)

    2002-06-01

    Astronomers using the National Science Foundation's Very Long Baseline Array (VLBA) radio telescope have found that an aging star is spewing narrow, rotating streams of water molecules into space, like a jerking garden hose that has escaped its owner's grasp. The discovery may help resolve a longstanding mystery about how the stunningly beautiful objects called planetary nebulae are formed. Artist's Conception of W43A. Artist's conception of W43A, with the aging star surrounded by a disk of material and a precessing, twisted jet of molecules streaming away from it in two directions. Credit: Kirk Woellert/National Science Foundation. The astronomers used the VLBA, operated by the National Radio Astronomy Observatory, to study a star called W43A. W43A is about 8,500 light-years from Earth in the direction of the constellation Aquila, the eagle. This star has come to the end of its normal lifetime and, astronomers believe, is about to start forming a planetary nebula, a shell of brightly glowing gas lit by the hot ember into which the star will collapse. "A prime mystery about planetary nebulae is that many are not spherical even though the star from which they are ejected is a sphere," said Phillip Diamond, director of the MERLIN radio observatory at Jodrell Bank in England, and one of the researchers using the VLBA. "The spinning jets of water molecules we found coming from this star may be one mechanism for producing the structures seen in many planetary nebulae," he added. The research team, led by Hiroshi Imai of Japan's National Astronomical Observatory (now at the Joint Institute for VLBI in Europe, based in the Netherlands), also includes Kumiko Obara of the Mizusawa Astrogeodynamics Observatory and Kagoshima University; Toshihiro Omodaka, also of Kagoshima University; and Tetsuo Sasao of the Japanese National Astronomical Observatory. The scientists reported their findings in the June 20 issue of the scientific journal Nature. As stars similar to our Sun

  20. Ventricle wall dissection and vascular preservation with the pulsed water jet device: novel tissue dissector for flexible neuroendoscopic surgery.

    Science.gov (United States)

    Kawaguchi, Tomohiro; Nakagawa, Atsuhiro; Endo, Toshiki; Fujimura, Miki; Sonoda, Yukihiko; Tominaga, Teiji

    2016-03-01

    Neuroendoscopic surgery allows minimally invasive surgery, but lacks effective methods to control bleeding. Water jet dissection with continuous flow has been used in liver and kidney surgery since the 1980s, and is effective for tissue manipulation with vascular preservation, but involves some potential risks, such as elevation of intracranial pressure during application in the ventricles. The authors previously reported the efficacy of the actuator-driven pulsed water jet device (ADPJ) to dissect soft tissue with vascular preservation in microscopic neurosurgery. This feasibility study investigated the use of the ADPJ to reduce the amount of water usage, leading to more safety with sustained efficacy. A small-diameter pulsed water jet device was developed for use with the flexible neuroendoscope. To identify the optimal conditions for the water jet, the flow rate, water pressure, and distance between the nozzle and target were analyzed in an in vitro study by using a gelatin brain phantom. A ventricle model was used to monitor the internal pressure and temperature. For ex vivo experiments the porcine brain was harvested and ventricle walls were exposed, and subsequently immersed into physiological saline. For in vivo experiments the cortex was microsurgically resected to make the small cortico-ventricle window, and then the endoscope was introduced to dissect ventricle walls. In the in vitro experiments, water pressure was approximately 6.5 bar at 0.5 mm from the ADPJ nozzle and was maintained at 1 mm, but dropped rapidly toward 50% at 2 mm, and became 10% at 3.5 mm. The ADPJ required less water to achieve the same dissection depth compared with the continuous-flow water jet. With the ventricle model, the internal pressure and temperature were well controlled at the baseline, with open water drainage. These results indicated that the ADPJ can be safely applied within the ventricles. The ADPJ was introduced into a flexible endoscope and the ventricle walls were

  1. 医用水刀的应用与实现%Application and Realization of Medical Water-jet

    Institute of Scientific and Technical Information of China (English)

    郑伟; 张西正

    2011-01-01

    The structure, the operating principle of medical water-jet and its application in the medical field are studied. The function which its control system should realize, that is, to achieve the constant pressure water supply as well as the hydraulic pressure limitless velocity modulation is defined. The frequency control constant pressure water supply technology is applied to achieve this function. Some other parts are added to develop the water-jet which is applied as the medical equipment. Medical water-jet has the broad prospect in the surgical operation domain because of its merits such as selective and protective cutting. In the future, water-jet will be used widely in the country gradually.%研究了医用水刀的结构、工作原理及其在医学领域的应用,明确了其控制系统所需实现恒压供水以及水压的无级调速功能,应用变频调速恒压供水技术可实现这一功能,增加了一些其他功能部件,开发出了应用于医学上的水刀设备,指出医用水刀的选择性和保护性切割等优点使其在外科手术领域具有广阔的前景,在不久的将来会在国内逐步得到推广应用.

  2. The Research into the Quality of Rock Surfaces Obtained by Abrasive Water Jet Cutting

    Science.gov (United States)

    Młynarczuk, Mariusz; Skiba, Marta; Sitek, Libor; Hlaváček, Petr; Kožušníková, Alena

    2014-12-01

    In recent years, water jet cutting technology has been being used more and more often, in various domains of human activity. Its numerous applications include cutting different materials - among them, rock materials. The present paper discusses the results of the research that aimed at determining - in a quantitative manner - the way in which the water jet cutting parameters (such as the traverse speed of the head, and the distance between the high-pressure inlet of the water jet and the cut material) influence the quality of the processed surface. Additionally, the impact of these parameters on the surface of various materials was investigated. The materials used were three granites differing with respect to the size of grains. In the course of the research, the standard parameters defined by the ISO norms were analyzed. It was also proposed that variograms be used to analyze the quality of the cut surface. Technologia cięcia strumieniem wodnym staje się w ostatnich latach coraz intensywniej wykorzystywana w różnych dziedzinach działalności człowieka. Jest ona wykorzystywana do obróbki różnorodnych materiałów, również materiałów skalnych. W ramach badań analizowano trzy granity różniące się m.in. wielkościami ziarn, które były przecinane przy różnych prędkościach przesuwu głowicy z wlotem strumienia wodnego. Analizowano standardowe parametry zdefiniowane w normach ISO jak również zaproponowano wykorzystanie wariogramów do analizy jakości wyciętej powierzchni. W pracy opisano w sposób ilościowy zmiany jakości powierzchni skał ciętych strumieniem wodnym ze ścierniwem w zależności od prędkości przesuwu głowicy, jak również w zależności od odległości przecinanego fragmentu powierzchni od wlotu strumienia wodnego do materiału. Wyniki uzyskane w pomiarach wskazują też na wpływ wielkości uziarnienia skały na jakość otrzymanej powierzchni. Jest to szczególnie widoczne dla najmniej optymalnych parametrów ci

  3. CFD Code Validation against Stratified Air-Water Flow Experimental Data

    Directory of Open Access Journals (Sweden)

    F. Terzuoli

    2008-01-01

    Full Text Available Pressurized thermal shock (PTS modelling has been identified as one of the most important industrial needs related to nuclear reactor safety. A severe PTS scenario limiting the reactor pressure vessel (RPV lifetime is the cold water emergency core cooling (ECC injection into the cold leg during a loss of coolant accident (LOCA. Since it represents a big challenge for numerical simulations, this scenario was selected within the European Platform for Nuclear Reactor Simulations (NURESIM Integrated Project as a reference two-phase problem for computational fluid dynamics (CFDs code validation. This paper presents a CFD analysis of a stratified air-water flow experimental investigation performed at the Institut de Mécanique des Fluides de Toulouse in 1985, which shares some common physical features with the ECC injection in PWR cold leg. Numerical simulations have been carried out with two commercial codes (Fluent and Ansys CFX, and a research code (NEPTUNE CFD. The aim of this work, carried out at the University of Pisa within the NURESIM IP, is to validate the free surface flow model implemented in the codes against experimental data, and to perform code-to-code benchmarking. Obtained results suggest the relevance of three-dimensional effects and stress the importance of a suitable interface drag modelling.

  4. Long-Term Stability of Residual Stress Improvement by Water Jet Peening Considering Working Processes.

    Science.gov (United States)

    Hashimoto, Tadafumi; Osawa, Yusuke; Itoh, Shinsuke; Mochizuki, Masahito; Nishimoto, Kazutoshi

    2013-06-01

    To prevent primary water stress corrosion cracking (PWSCC), water jet peening (WJP) has been used on the welds of Ni-based alloys in pressurized water reactors (PWRs). Before WJP, the welds are machined and buffed in order to conduct a penetrant test (PT) to verify the weld qualities to access, and microstructure evolution takes place in the target area due to the severe plastic deformation. The compressive residual stresses induced by WJP might be unstable under elevated temperatures because of the high dislocation density in the compressive stress layer. Therefore, the stability of the compressive residual stresses caused by WJP was investigated during long-term operation by considering the microstructure evolution due to the working processes. The following conclusions were made: The compressive residual stresses were slightly relaxed in the surface layers of the thermally aged specimens. There were no differences in the magnitude of the relaxation based on temperature or time. The compressive residual stresses induced by WJP were confirmed to remain stable under elevated temperatures. The stress relaxation at the surface followed the Johnson-Mehl equation, which states that stress relaxation can occur due to the recovery of severe plastic strain, since the estimated activation energy agrees very well with the self-diffusion energy for Ni. By utilizing the additivity rule, it was indicated that stress relaxation due to recovery is completed during the startup process. It was proposed that the long-term stability of WJP under elevated temperatures must be assessed based on compressive stresses with respect to the yield stress. Thermal elastic-plastic creep analysis was performed to predict the effect of creep strain. After 100 yr of simulated continuous operation at 80% capacity, there was little change in the WJP compressive stresses under an actual operating temperature of 623 K. Therefore, the long-term stability of WJP during actual operation was

  5. Microcutting of living brain slices by a pulsed ultrafine water jet which allows simultaneous electrophysiological recordings (micromingotome).

    Science.gov (United States)

    Speckmann, E J; Köhling, R; Lücke, A; Straub, H; Wittkowski, W; Elger, C E; Wiemann, M; Bingmann, D

    1998-07-01

    Up to now microsurgical dissections in living nervous tissue (e.g. in slices or cell cultures) are performed either by micro-scalpels or by laser beams. As an alternative technique, a device for cutting with an ultrafine pulsed water jet was developed to allow precise, visually controled dissections in neuronal circuits even during electrophysiological recordings. Water is ejected by pressure (20-30 bar) from patch pipettes with tip diameters of 10-12 microm. By means of a piezo-element the pipette and the water jet are forced to oscillate vertically with a frequency of 200-400 Hz with an adjustable amplitude. These oscillations facilitate the transsection of neuronal connections even in thick slice preparations. Best results were obtained when the tip of the pipette was about 500 microm above the surface of the submerged slice tissue. This micromingotome offers the following advantages: (i) histological studies show that the water jet cleans the cutting surface, thus avoiding debris and its uncontrolable effects on cells underneath; (ii) the arrangement enables ongoing electrophysiological recordings from hippocampal slices during the cutting procedure and thus facilitates studies of the functions of neuronal connections; (iii) the device allows even disconnection in cultured nervous tissue overgrowing polyamid grids with 50 microm wide meshes.

  6. Measuring Magnetic Fields from Water Masers in the Synchrotron Protostellar Jet in W3(H$_2$O)

    CERN Document Server

    Goddi, C; Moscadelli, L; Imai, H; Vlemmings, W H T; van Langevelde, H J; Sanna, A

    2016-01-01

    We report full polarimetric VLBA observations of water masers towards the Turner-Welch Object in the W3(OH) high-mass star forming complex. This object drives a synchrotron jet, which is quite exceptional for a high-mass protostar, and is associated with a strongly polarized water maser source, W3(H$_2$O), making it an optimal target to investigate the role of magnetic fields on the innermost scales of protostellar disk-jet systems. The linearly polarized emission from water masers provides clues on the orientation of the local magnetic field, while the measurement of the Zeeman splitting from circular polarization provides its strength. The water masers trace a bipolar, biconical outflow at the center of the synchrotron jet. Although on scales of a few thousand AU the magnetic field inferred from the masers is on average orientated along the flow axis, on smaller scales (10s to 100s of AU), we have revealed a misalignment between the magnetic field and the velocity vectors, which arises from the compression ...

  7. Application of water jet assisted drag bit and pick cutter for the cutting of coal measure rocks. Final technical report. [Tests of combination in different rocks

    Energy Technology Data Exchange (ETDEWEB)

    Ropchan, D.; Wang, F.D.; Wolgamott, J.

    1980-04-01

    A laboratory investigation was made of the effects of high pressure water jets on the cutting forces of drag bit cutters in sedimentary rocks. A hard and soft sandstone, shale and limestone were tested with commercially obtainable conical and plow type drag bits on the EMI linear cutting machine. About 1200 cuts were made at different bit penetration, jet orientation, and water pressure to determine the reduction of cutting forces on the bit from the use of the water jet. Both independent and interactive cutting was used. The greatest reduction in cutting forces were with both of the sandstones; the drag forces were reduced about 30 percent and the normal forces about 60 percent at 5000 psi water pressure with the nozzle behind the bit. The method was less effective in the shale, except at 10,000 psi water pressure the reduction in drag force was about 55 percent. Of the rocks tested, the limestone was least affected by the water jet. The cutting forces for the plow bit showed continuous change with wear so a machined conical bit was used for most of the testing. Tests with the plow bit did show a large reduction in cutting forces by using the water jet with worn bits. An economic analysis of equipping a drag bit tunnel boring machine indicated that the water jet system could reduce costs per foot in sandstone by up to 40 percent.

  8. A correlation for predicting the abrasive water jet cutting depth for natural stones

    Directory of Open Access Journals (Sweden)

    Irfan C. Engin

    2012-09-01

    Full Text Available The abrasive water jet (AWJ cutting method has been used widely for the cutting and processing of materials because of its cool, damage-free, and precise cutting technique. Nowadays, the use of AWJ cutting in the natural stone industry is increasing. However, the effectiveness of AWJ cutting of natural stones is dependent on the rock properties and machine operating parameters. In this study, injection-type AWJ cutting was applied to 42 different types of natural stones to investigate the effects of rock properties and operating parameters on the cutting depth. Shore hardness, Bohme surface abrasion resistance and the density of the rocks were the most significant rock properties affecting the cutting depth. The working pump pressure and traverse velocity were the most significant operating parameters affecting cutting, as has been shown previously. The relationships between the rock properties or operating parameters and the cutting depth were evaluated using multiple linear and nonlinear regression analyses, and estimation models were developed. Some of the models included only rock properties under fixed operating conditions, and others included both rock properties and operating parameters to predict cutting depth. The models allow for the preselection of particular operating parameters for the cutting of specific rocks types. The prediction of cutting depth is a valuable tool for the controlled surface machining of rock materials.

  9. Influence of Water-jet Nozzle Geometry on Cutting Ability of Soft Material

    Directory of Open Access Journals (Sweden)

    Irwansyah Irwansyah

    2012-06-01

    Full Text Available Hygiene is main reason for food processor to use waterjet cutting system. Traditionally food cutting process is low-quality, unsafe products, procedures and direct contact between product and labor. This paper introduced a low cost waterjet system for cutting soft material as identic food material. The low cost waterjet system has been developed by using a commercial pressure pump for cleaning purposes and modified nozzle. In order to enhance waterjet pressure for cutting products, a modified waterjet nozzle was designed. Paramater design of waterjet system was setup on nozzle orifice diameter 0.5 mm, standoff distance 15 mm, length of nozzle cylindrical tube 2.5 mm. Polycarbonate, polysterene, and polyethelene materials are used as sample product with thickness 2 mm, to represent similar properties with agriculture products. The experimental results indicate good possibilities of waterjet system to cut material in appropriate profile surface. The waterjet also can be used to improve cutting finished surface of food products. Therefore, utilizing a low cost commercial pump and modified nozzle for waterjet system reduces equipment price, operational cost and environmental hazards. It indicates viable technology applied to substitute traditional cutting technology in post harvest agriculture products. Keywords: cutting ability, modified nozzle, polymer material, water-jet system

  10. Simulation of abrasive water jet cutting process: Part 1. Unit event approach

    Science.gov (United States)

    Lebar, Andrej; Junkar, Mihael

    2004-11-01

    Abrasive water jet (AWJ) machined surfaces exhibit the texture typical of machining with high energy density beam processing technologies. It has a superior surface quality in the upper region and rough surface in the lower zone with pronounced texture marks called striations. The nature of the mechanisms involved in the domain of AWJ machining is still not well understood but is essential for AWJ control improvement. In this paper, the development of an AWJ machining simulation is reported on. It is based on an AWJ process unit event, which in this case represents the impact of a particular abrasive grain. The geometrical characteristics of the unit event are measured on a physical model of the AWJ process. The measured dependences and the proposed model relations are then implemented in the AWJ machining process simulation. The obtained results are in good agreement in the engraving regime of AWJ machining. To expand the validity of the simulation further, a cellular automata approach is explored in the second part of the paper.

  11. Separation and reconstruction of high pressure water-jet reflective sound signal based on ICA

    Science.gov (United States)

    Yang, Hongtao; Sun, Yuling; Li, Meng; Zhang, Dongsu; Wu, Tianfeng

    2011-12-01

    The impact of high pressure water-jet on the different materials target will produce different reflective mixed sound. In order to reconstruct the reflective sound signals distribution on the linear detecting line accurately and to separate the environment noise effectively, the mixed sound signals acquired by linear mike array were processed by ICA. The basic principle of ICA and algorithm of FASTICA were described in detail. The emulation experiment was designed. The environment noise signal was simulated by using band-limited white noise and the reflective sound signal was simulated by using pulse signal. The reflective sound signal attenuation produced by the different distance transmission was simulated by weighting the sound signal with different contingencies. The mixed sound signals acquired by linear mike array were synthesized by using the above simulated signals and were whitened and separated by ICA. The final results verified that the environment noise separation and the reconstruction of the detecting-line sound distribution can be realized effectively.

  12. Cutting of living hippocampal slices by a highly pressurised water jet (macromingotome).

    Science.gov (United States)

    Bingmann, D; Wiemann, M; Speckmann, E J; Köhling, R; Straub, H; Dunze, K; Wittkowski, W

    2000-10-15

    Living brain slices are usually cut with razor blades, which compress a ca. 50-microm-thick layer of tissue. This results in cell debris and lesioned cells which, e.g. form diffusion barriers between the bath and living neurons underneath, thereby prolonging response times of neurons to drugs in the bath saline and impeding the experimental access to intact neurons. To avoid such drawbacks, a macromingotome was developed which cuts nervous tissue with water jets. Physiological saline under pressures of 100-1800 bar was ejected through nozzles of 35-100 microm to cut 300-500-microm-thick hippocampal slices. Systematic variations of pressure and nozzle diameter revealed best results at 400-600 bar and with nozzle diameters of 60-80 microm. Under these conditions, intact CA1- and CA3-neurons as well as granule cells were detected with infrared microscopy at less than 10 microm underneath the surface of the slice. Superficial neurons with intact fine structures were also seen when the slices were studied by light-microscopy. Intra- and extracellular recordings from superficial neurons showed normal membrane- and full action potentials and the development of stable epileptiform discharges in 0 Mg(2+)-saline. These results indicate that the macromingotome offers an alternative way of cutting slices which may facilitate electrophysiological/neuropharmacological or fluorometric studies on superficial neurons.

  13. Cost minimizing of cutting process for CNC thermal and water-jet machines

    Science.gov (United States)

    Tavaeva, Anastasia; Kurennov, Dmitry

    2015-11-01

    This paper deals with optimization problem of cutting process for CNC thermal and water-jet machines. The accuracy of objective function parameters calculation for optimization problem is investigated. This paper shows that working tool path speed is not constant value. One depends on some parameters that are described in this paper. The relations of working tool path speed depending on the numbers of NC programs frames, length of straight cut, configuration part are presented. Based on received results the correction coefficients for working tool speed are defined. Additionally the optimization problem may be solved by using mathematical model. Model takes into account the additional restrictions of thermal cutting (choice of piercing and output tool point, precedence condition, thermal deformations). At the second part of paper the non-standard cutting techniques are considered. Ones may lead to minimizing of cutting cost and time compared with standard cutting techniques. This paper considers the effectiveness of non-standard cutting techniques application. At the end of the paper the future research works are indicated.

  14. Laser Doppler vibrometry experiment on a piezo-driven slot synthetic jet in water

    Directory of Open Access Journals (Sweden)

    Broučková Zuzana

    2015-01-01

    Full Text Available The present study deals with a slot synthetic jet (SJ issuing from an actuator into quiescent surroundings and driven by a piezoceramic transducer. The actuator slot width was 0.36 mm, with a drive frequency proposed near the theoretical natural frequency of the actuator. The working fluid was water at room temperature. The present experiments used flow visualization (a laser-induced fluorescence technique and laser Doppler vibrometry methods. Flow visualization was used to identify SJ formation, to demonstrate its function, and to estimate SJ velocity. Laser Doppler vibrometry was used to quantify diaphragm displacement and refine operating parameters. Phase averaging yielded a spatial and temporal diaphragm deflection during the actuation period. Taking incompressibility and continuity into consideration, the velocity in the actuator slot and the Reynolds number of the SJ were evaluated as 0.21 m/s and 157, respectively. The present results confirmed a SJ actuator function at the resonance frequency of approximately 46 Hz, which corresponds closely with the theoretical evaluation. The laser Doppler vibrometry results corresponded closely with an estimation of SJ velocity by the present flow visualization.

  15. Endoscopic submucosal dissection of early gastric neoplasia with a water jet-assisted knife: a Western, single-center experience.

    Science.gov (United States)

    Schumacher, Brigitte; Charton, Jean-Pierre; Nordmann, Thomas; Vieth, Michael; Enderle, Markus; Neuhaus, Horst

    2012-06-01

    Endoscopic submucosal dissection (ESD) of early gastric neoplasia has not yet been established in Western countries because of a lack of data and the difficult, time-consuming, and hazardous nature of the method. Some of the technical limitations may be overcome by use of a water jet-assisted knife, which allows a combination of a high-pressure water jet and electrosurgical interventions. To evaluate the efficacy and safety of water jet-assisted ESD (WESD) with a water jet-assisted knife in selected patients with early gastric neoplasia. Single-center, prospective study. This study involved 29 consecutive patients (13 female; median age 61 years; age range 35-93 years) with early gastric neoplasia that met the expanded criteria of the Japanese Gastric Cancer Association. Histology of biopsies had shown gastric adenocarcinoma in 21 cases, adenoma in 8 case, and suspicion of a GI stromal tumor in 1 case. The median maximal diameter of the lesions was 20 mm (range 10-40 mm). All procedures were done with patients under sedation with propofol. The water jet-assisted knife was used for setting coagulation markers around the neoplastic lesions, then for circumferential incision and dissection in combination with repeated submucosal injection of saline solution with a water jet system. Bleeding was treated with diathermia by use of the water jet-assisted knife or hemostatic forceps in case of failure or larger vessels. Clips were used for closure of perforations. Complete resection of neoplasia, procedure time, complication and recurrence rates. According to endoscopic criteria, complete resection of the targeted area could be achieved in all cases, with an en bloc resection rate of 90%. The median procedure duration was 74 minutes (range 15-402 minutes). Exchange of the device was needed in only 10 cases because of severe bleeding from larger vessels, which could be managed by use of hemostatic forceps. The 30-day morbidity rate was 4 of 30 (13.8%) because of

  16. Gingival foreign body granuloma in conjunction with the use of a dental water jet: a case report.

    Science.gov (United States)

    Terry, Mark A; Narayana, Nagamani; Kaldahl, Wayne B

    2014-01-01

    Foreign body gingivitis has been described as an inflammatory reaction of marginal or attached gingival tissues due to foreign material in the connective tissue. This article presents the case of a 58-year-old woman with the chief complaint of periodic discomfort in her maxillary "gums" and redness in the facial gingival tissues of the maxillary anterior segment. A biopsy showed a granulomatous reaction in both the red and neutral areas. The patient revealed that she had been using a water jet device on a high pressure setting. She was advised to discontinue the water jet use, after which the gingival redness and inflammation began to subside, and appeared normal at 3- and 6-month follow-up visits.

  17. Effect of Pressure, Feed Rate, and Abrasive Mass Flow Rate on Water Jet Cutting Efficiency When Cutting Recombinant Bamboo

    Directory of Open Access Journals (Sweden)

    Rongrong Li

    2014-11-01

    Full Text Available The impact of varying pressure, feed rate, and abrasive mass flow rate on the efficiency of an abrasive water jet cutting process was studied in this work. Recombinant bamboo samples with thicknesses of 5, 10, and 15 mm were cut by the abrasive water jet. The upper kerf width, lower kerf width, and the ratio of the upper kerf width to lower kerf width were chosen as the efficiency parameters. Mathematical models were developed to describe the relationship between the input process parameters and the efficiency parameters. The arrangement of experiments and analysis of results were performed based on response surface methodology. The evaluated model yielded predictions in agreement with experimental results.

  18. 水射流辅助刀具切削钴结壳%Water jet assist cutter cutting cobalt crusts

    Institute of Scientific and Technical Information of China (English)

    黄中华; 谢雅

    2012-01-01

    In order to reduce impact load and improve working safety of miner, deepsea cobalt crusts cutting method of water jet assist cutter was proposed. Stress analysis of cutter cutting cobalt crusts with single teeth was analyzed and mechanical model of water jet assist cutter cutting deepsea cobalt crusts was established. With simulation calculation, the relationship between water jet pressure and minimum cutting force of cutter was obtained, which was needed to generate initial crack on cobalt crust surface. Simulation results are as follows; compared with cutter cutting, when water jet working point is overlap with cutter working point, the minimum cutting force is decreased. With the increasing of water jet pressure, the minimum cutting force decreased dramatic. Experiments of water jet assist cutter cutting cobalt crusts simulation material were carried out. Experimental results are as follows; compared with cutter cutting, the maximum impact load is decreased when water jet assist cutter cutting cobalt crusts. When water jet pressure is 5 Mpa, the maximum impact load is decreased by 50% and the RMS impact load is decreased by 10%.%为了减小钴结壳切削过程中产生的冲击载荷,提高集矿机的行走安全性,提出了水射流辅助刀具切削钴结壳的切削方法.分析了单个截齿切削钴结壳时的受力情况,建立了水射流辅助刀具切削钴结壳的力学模型,通过仿真计算获取了水射流压力和刀具在钴结壳表面产生初始裂纹所需最小切削力的作用规律.仿真结果表明:与纯刀具切削相比,当水射流作用点和刀具作用点重合时,刀具在钴结壳表面产生初始裂纹所需的最小切削力明显下降;随着水射流压力的增加,刀具所需的最小切削力急剧下降.开展了水射流辅助刀具切削钴结壳模拟料实验.实验结果表明:与纯刀具切削钴结亮相比,水射流辅助刀具切削钴结壳时,切削过程中冲击载荷的最大值明

  19. Exploration of water jet generated by Q-switched laser induced water breakdown with different depths beneath a flat free surface.

    Science.gov (United States)

    Chen, Ross C C; Yu, Y T; Su, K W; Chen, J F; Chen, Y F

    2013-01-14

    The dynamics of a water jet on a flat free surface are investigated using a nanosecond pulsed laser for creating an oscillating bubble with different depths beneath the free surface. A thin jet is shown to deform a crater surface resulted from surface depression and cause a circular ring-shaped crater on the connection surface between the crater of surface depression and the thin jet. The collapse of this circular ring-shaped crater is proposed to the crown-like formation around a thick jet. The evolution of the bubble depth suggests a classification of four distinctive ranges of the bubble depths: non-crown formation when the parameter of bubble depth over the maximum bubble radius γ ≤ 0.5, unstable crown formation when 0.5 ≤ γ ≤ 0.6, crown-like structure with a complete crown wall when 0.6 ≤ γ ≤ 1.1, and non-crown formation when 1.1 ≤ γ. Furthermore, the orientation of the crown wall gradually turns counterclockwise to vertical direction with increasing γ from 0.5 to 1.1, implying a high correlation between the orientation of the crown wall and the depth of the bubble. This correlation is explained and discussed by the directional change of the jet eruption from the collapse of circular ring-shaped crater.

  20. Pseudomonas aeruginosa outbreak in a pediatric oncology care unit caused by an errant water jet into contaminated siphons.

    Science.gov (United States)

    Schneider, Henriette; Geginat, Gernot; Hogardt, Michael; Kramer, Alexandra; Dürken, Matthias; Schroten, Horst; Tenenbaum, Tobias

    2012-06-01

    We analyzed an outbreak of invasive infections with an exotoxin U positive Pseudomonas aeruginosa strain within a pediatric oncology care unit. Environmental sampling and molecular characterization of the Pseudomonas aeruginosa strains led to identification of the outbreak source. An errant water jet into the sink within patient rooms was observed. Optimized outbreak management resulted in an abundance of further Pseudomonas aeruginosa infections within the pediatric oncology care unit.

  1. The Cutting Front Side Geometry in The Applications of D3 Cold Work Tool Steel Material Via Abrasive Water Jet

    OpenAIRE

    Adnan AKKURT

    2013-01-01

    Abrasive water jet cutting that is used as cold cutting technology in industrial applications is preferred as most productive method when especially metallurgic and mechanic specialties of materials are taken into consideration. When the surface quality, speed of processing period and part cost are taken into consideration, which are targeted in D3 cold work tool steel materials used frequently in especially metal industry, it appears that the most appropriate method is ab...

  2. Water-Air Mixing Jet Produced by Electro-hydraulic Impulse Technology Strengthening the Quality of Surface of Metal Materials

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Electro-hydraulic impulse water-air mixing jet by which the quality of metal materials can be improved is described in this paper. The experimental results proved that the hardness and the micro-hardness of the surface layer of metal materials can be improved with this method, for example, the microhardness of CrWMn can be increased by 35.62percent.

  3. Numerical Investigation of Nozzle Geometry Effect on Turbulent 3-D Water Offset Jet Flows

    Directory of Open Access Journals (Sweden)

    Negar Mohammad Aliha

    2016-01-01

    Full Text Available Using the Yang-Shih low Reynolds k-ε turbulence model, the mean flow field of a turbulent offset jet issuing from a long circular pipe was numerically investigated. The experimental results were used to verify the numerical results such as decay rate of streamwise velocity, locus of maximum streamwise velocity, jet half width in the wall normal and lateral directions, and jet velocity profiles. The present study focused attention on the influence of nozzle geometry on the evolution of a 3D incompressible turbulent offset jet. Circular, square-shaped, and rectangular nozzles were considered here. A comparison between the mean flow characteristics of offset jets issuing from circular and square-shaped nozzles, which had equal area and mean exit velocity, were made numerically. Moreover, the effect of aspect ratio of rectangular nozzles on the main features of the flow was investigated. It was shown that the spread rate, flow entrainment, and mixing rate of an offset jet issuing from circular nozzle are lower than square-shaped one. In addition, it was demonstrated that the aspect ratio of the rectangular nozzles only affects the mean flow field of the offset jet in the near field (up to 15 times greater than equivalent diameter of the nozzles. Furthermore, other parameters including the wall shear stress, flow entrainment and the length of potential core were also investigated.

  4. Evaluation of water jet morcellation as an alternative to hand morcellation of renal tissue ablation during laparoscopic nephrectomy: an in vitro study.

    Science.gov (United States)

    Varkarakis, John M; McAllister, Marc; Ong, Albert M; Solomon, Stephen B; Allaf, Mohamad E; Inagaki, Takeshi; Bhayani, Sam B; Trock, Bruce; Jarrett, Thomas W

    2004-04-01

    To evaluate the feasibility and safety of morcellation with a new prototype device that uses high-pressure water flow as a cutting/ablating tool and compare it with standard manual morcellation. Ten porcine kidneys were morcellated with the new water jet device and ten with conventional manual morcellation. Morcellation in all cases was performed in commercially available entrapment bags. The two groups were evaluated for morcellation time, fragment size, and perforation rates (macroscopic and microscopic). The kidney size in both groups was similar. Morcellation was significantly (P water jet morcellator group than in the hand morcellation group (5.6 versus 11.9 minutes). The macroscopic evaluation after filling the entrapment bags with normal saline revealed 4 (40%) and 2 (20%) pinhole perforations in the water jet and hand morcellation groups, respectively. The microscopic evaluation revealed an 80% perforation rate in the water jet group and a 20% rate in the hand morcellator group. The size of the resulting fragments in the water jet group was not available, because the morcellated kidney was transformed in a semiliquid form. Therefore, cytology evaluation of the tissue was not possible. Water jet technology can be used to morcellate renal porcine tissue effectively. It is faster, but the problems of safety and histologic evaluation must be solved before this promising technology can be used in a clinical setting.

  5. Selection of the most influential factors on the water-jet assisted underwater laser process by adaptive neuro-fuzzy technique

    Science.gov (United States)

    Nikolić, Vlastimir; Petković, Dalibor; Lazov, Lyubomir; Milovančević, Miloš

    2016-07-01

    Water-jet assisted underwater laser cutting has shown some advantages as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. It is important to determine which parameters are the most important for the process. In this investigation was analyzed the water-jet assisted underwater laser cutting parameters forecasting based on the different parameters. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for water-jet assisted underwater laser cutting parameters forecasting. Three inputs are considered: laser power, cutting speed and water-jet speed. The ANFIS process for variable selection was also implemented in order to detect the predominant factors affecting the forecasting of the water-jet assisted underwater laser cutting parameters. According to the results the combination of laser power cutting speed forms the most influential combination foe the prediction of water-jet assisted underwater laser cutting parameters. The best prediction was observed for the bottom kerf-width (R2 = 0.9653). The worst prediction was observed for dross area per unit length (R2 = 0.6804). According to the results, a greater improvement in estimation accuracy can be achieved by removing the unnecessary parameter.

  6. A novel method to obtain modulus image of soft tissues using ultrasound water jet indentation: a phantom study.

    Science.gov (United States)

    Lu, Min-Hua; Zheng, Yong-Ping; Huang, Qing-Hua

    2007-01-01

    The alteration of tissue stiffness is generally known to be associated with pathological changes. Ultrasound indentation is one of the methods that can be used to assess the mechanical properties of the soft tissues. It uses a flat-ended ultrasound transducer to directly contact the tissue to sense tissue deformation under an applied load. This paper introduced a novel noncontact ultrasound indentation system using water jet compression. The key idea was to utilize a water jet as the indenter as well as the coupling medium for propagation of the ultrasound beam. High frequency focused ultrasound (20 MHz) was used to measure the indentation deformation at a microscopic level. It has been demonstrated that the system could effectively assess the tissue-mimic phantoms with different stiffness. Water jet coupling allows the system to conduct C-scan on soft tissues rapidly and conveniently. By applying different pressures while taking C-scan sequences, the modulus images of the phantoms could be obtained based on the applied pressure and the phantom deformation and thickness. This paper presented the preliminary results on gel phantoms. The spatial resolution, the contrast resolution of the measurements and the reproducibility of the results were also discussed.

  7. Quantitative imaging of young's modulus of soft tissues from ultrasound water jet indentation: a finite element study.

    Science.gov (United States)

    Lu, Min-Hua; Mao, Rui; Lu, Yin; Liu, Zheng; Wang, Tian-Fu; Chen, Si-Ping

    2012-01-01

    Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young's modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson's ratio using Hayes' equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes' equation has been derived by introducing a new scaling factor which is dependent on Poisson's ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue), and deformation ratio d/h. With this model, the Young's modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%.

  8. Quantitative Imaging of Young’s Modulus of Soft Tissues from Ultrasound Water Jet Indentation: A Finite Element Study

    Directory of Open Access Journals (Sweden)

    Min-Hua Lu

    2012-01-01

    Full Text Available Indentation testing is a widely used approach to evaluate mechanical characteristics of soft tissues quantitatively. Young’s modulus of soft tissue can be calculated from the force-deformation data with known tissue thickness and Poisson’s ratio using Hayes’ equation. Our group previously developed a noncontact indentation system using a water jet as a soft indenter as well as the coupling medium for the propagation of high-frequency ultrasound. The novel system has shown its ability to detect the early degeneration of articular cartilage. However, there is still lack of a quantitative method to extract the intrinsic mechanical properties of soft tissue from water jet indentation. The purpose of this study is to investigate the relationship between the loading-unloading curves and the mechanical properties of soft tissues to provide an imaging technique of tissue mechanical properties. A 3D finite element model of water jet indentation was developed with consideration of finite deformation effect. An improved Hayes’ equation has been derived by introducing a new scaling factor which is dependent on Poisson’s ratios v, aspect ratio a/h (the radius of the indenter/the thickness of the test tissue, and deformation ratio d/h. With this model, the Young’s modulus of soft tissue can be quantitatively evaluated and imaged with the error no more than 2%.

  9. Histologic effects of different technologies for dissection in endoscopic surgery: Nd:YAG laser, high frequency and water-jet.

    Science.gov (United States)

    Schurr, M O; Wehrmann, M; Kunert, W; Melzer, A; Lirici, M M; Trapp, R; Kanehira, E; Buess, G

    1994-01-01

    Precise cutting combined with reliable coagulation of the margins of the lesion is an important requirement for dissection techniques in endoscopic surgery. These requirements are met by the two most common ancillary energy sources applied for endoscopic dissection today, electrosurgery and "thermal lasers", mostly the Nd:YAG. For the comparison of the histological effects of monopolar and bipolar high frequency with the Nd:YAG laser an experimental in vitro and in vivo study has been performed. In order to evaluate the advantages of non thermal dissection for endoscopic procedures, a water jet cutting system was included in the in vitro study. In parenchymatous tissue the water jet was found to be the least traumatic technique, followed by bipolar high frequency, laser and monopolar high frequency. The water jet was not applicable for intestinal dissection since uncontrolled bloating of the rectal wall with uncontrolled disruption of the tissue layers occurred. A general disadvantage is that secure haemostasis in the line of incision is hard to achieve. In the microscopic comparison of the shape of the incision, the Nd:YAG laser produced the smoothest lesions with well-defined margins. The monopolar technique was more often associated with irregular and sometimes fissured margins. These results were confirmed in the in vivo part of the study (Transanal Endoscopic Microsurgery).

  10. Numerical and experimental study of Boussinesq wall horizontal turbulent jet of fresh water in a static homogeneous environment of salt water

    Institute of Scientific and Technical Information of China (English)

    BELCAID Aicha; LE PALEC Georges; DRAOUI Abdeslam

    2015-01-01

    This paper investigates a numerical and experimental study about buoyant wall turbulent jet in a static homogeneous environment. A light fluid of fresh water is injected horizontally and tangentially to a plane wall into homogenous salt water ambient. This later is given with different values of salinity and the initial fractional density is small, so the applicability of the Boussinesq approximation is valid. Since the domain temperature is assumed to be constant, the density of the mixture is a function of the salt concentration only. Mathematical model is based on the finite volume method and reports on an application of standardk-ε turbulence model for steady flow with densimetric Froude numbers of 1-75 and Reynolds numbers of 2 000-6 000. The basic features of the model are the conservation of mass, momentum and concentration. The boundaries of jet body, the radius and cling length are determined. It is found that the jet spreading and behavior depend on the ratio between initial buoyancy flux and momentum, i.e., initial Froude number, and on the influence of wall boundary which corresponds to Coanda effect. Laboratory experiments were conducted with photographic observations of jet trajectories and numerical results are described and compared with the experiments. A good agreement with numerical and experimental results has been achieved.

  11. The water jet as a new tool for endoprosthesis revision surgery--an in vitro study on human bone and bone cement.

    Science.gov (United States)

    Honl, Matthias; Rentzsch, Reemt; Schwieger, Karsten; Carrero, Volker; Dierk, Oliver; Dries, Sebastian; Louis, Hartmut; Pude, Frank; Bishop, Nick; Hille, Ekkehard; Morlock, Michael

    2003-01-01

    In revision surgeries of endoprostheses, the interface between implant and bone cement or bone must be loosened. Conventional tools have many disadvantages because of their size and limited range. Taking advantage of the selective and athermic cutting process, a plain water jet is already used in order to cut soft tissues. This study investigates the possibilities of both a plain and an abrasive water jet as cutting tools for revision surgery. Samples of the mid-diaphysis of human femora and bone cement (CMW3) were cut with a plain water jet (PWJ) and an abrasive water jet (AWJ) at two different jet-to-surface angles (30 degrees,90 degrees ) and at five different pressure levels (30, 40, 50, 60, 70 MPa). For a PWJ a selective pressure range was identified, where only bone cement was cut. Injecting a bio-compatible abrasive (lactose) to the jet stream resulted in significantly higher cut depths in both materials. Material removal in bone was significantly less at the smaller jet-to-surface angle for both techniques. No clear selectivity between bone and bone cement was observed for application of the AWJ. However, the material removal rate was significantly higher for bone cement than for bone at all pressure levels. The results indicate that an AWJ might be an alternative tool for cement removal. The possibility for localised cutting at interfaces could be an advantage for revision of a non-cemented prosthesis.

  12. Water jet dissection technique for endoscopic third ventriculostomy minimises the risk of bleeding and neurological complications in obstructive hydrocephalus with a thick and opaque third ventricle floor.

    Science.gov (United States)

    Yadav, Y R; Shenoy, R; Mukerji, G; Parihar, V

    2010-08-01

    Endoscopic third ventriculostomy (ETV) is a procedure of choice in the treatment of obstructive hydrocephalus. Neurovascular injury while perforating the ventricular floor can occur when using a conventional probe, especially in patients with a thick and opaque third ventricle floor. The water jet dissection technique can be useful in such cases to perform an initial perforation. The water jet dissection technique was used to perform ETV in 36 patients with obstructive hydrocephalus with a thick and opaque third ventricle floor over a 3-year period. A water jet was generated using a syringe connected to a 2-mm catheter. The water jet dissection technique successfully created a patent ETV stoma in 31 patients. 5 patients needed a re-operation due to a blocked stoma. There were no complications related to the procedure. An improvement in clinical function was seen in 28 (83.3%) patients at a median follow-up of 29 months. The water jet dissection is a useful technique while performing ETV to prevent neurovascular injury. Our improvised technique of creating a water jet is safe, inexpensive, readily available and can be practiced at any centre performing ETV. © Georg Thieme Verlag KG Stuttgart · New York.

  13. Fundamental tests and operational suitability tests in the field. Large diameter boring with water jets (2nd report)

    Energy Technology Data Exchange (ETDEWEB)

    Oga, Kotaro; Higuchi, Kiyoshi; Uehara, Masabumi

    1987-09-25

    The application test of large diameter boring in coal seams assisted with water jet was made and two plunger pumps were used. Maximum hydraulic pressure were 300Kg/cm/sup 2/ and 700Kg/cm/sup 2/ and maximum flow rate were 140l/min and 47l/min respectively. Jet water was injected from each nozzle through the pressure resistant hose. Basic test and application test results in Taiheiyo and Akabira mines were summarized as follows: lengths of boreholes were 38 to 78 m and bored diameters were 30 to 70cm. The bored diameter depended on the coal zone hardness and the in-situ stress and indicated similar tendency to the previous large diameter boring. Boring speed was 0.14 to 0.33m/min in case of high velocity jet stream and 0.09m/min at the large diameter boring. Two miners can set and withdraw the boring equipments including the drilling work. (7 figs, 8 tabs, 6 refs)

  14. Breast reconstruction de novo by water-jet assisted autologous fat grafting – a retrospective study

    Directory of Open Access Journals (Sweden)

    Hoppe, Delia Letizia

    2013-12-01

    Full Text Available [english] Background: Autologous fat grafting has become a frequent, simple, reproducible and low-risk technique for revisional or partial breast reconstruction. The presented European multicenter study describes an optimized treatment and follow-up protocol for the de novo breast reconstruction after total mastectomy by lipotransfer alone.Methods: A retrospective European multicenter trial included 135 procedures on 28 (35 breasts postmastectomy patients (mean 52.4 years. All women were treated with the water-jet assisted fat grafting method (BEAULI™ combined with additional procedures (NAC reconstruction, contralateral mastoplasty and evaluated with at least 6 months follow-up (mean 2.6 years. Sonography or mammography, clinical examination, patient questionnaire (10-point Likert scale and digital photographs were carried out.Results: On average the patients received 4 to 6 procedures each with a single volume of 159 ml (±61 ml over 21 months (range 9 months to 2.5 years. In total 1,020 ml (±515 ml fat were grafted till a complete breast reconstruction was achieved. Irradiated patients needed a significantly higher volume than non-irradiated (p<0.041. Main treatment complications were liponecrosis (2.59%, infection (0.74% and granuloma (0.74%. Patient satisfaction was overall high to very high (96% and confirmed the good aesthetic results (68% and the natural softness, contour and shape of the reconstructed breast.Conclusions: A complete breast reconstruction with large volume fat grafting is alternatively possible to standard techniques in selected cases. It takes at least 4 to 6 lipotransfers in the course of 2 years. Patients with prior radiotherapy may require even up to 8 sessions over nearly 3 years of treatment.

  15. Adipose Mesenchymal Stem Cells Isolated after Manual or Water-jet-Assisted Liposuction Display Similar Properties

    Science.gov (United States)

    Bony, Claire; Cren, Mailys; Domergue, Sophie; Toupet, Karine; Jorgensen, Christian; Noël, Danièle

    2016-01-01

    Mesenchymal stem or stromal cells (MSC) are under investigation in many clinical trials for their therapeutic potential in a variety of diseases, including autoimmune and inflammatory disorders. One of the main sources of MSCs is the adipose tissue, which is mainly obtained by manual liposuction using a cannula linked to a syringe. However, in the past years, a number of devices for fat liposuction intended for clinical use have been commercialized but few papers have compared these procedures in terms of stromal vascular fraction (SVF) or adipose mesenchymal stromal cells (ASC). The objective of the present study was to compare and qualify for clinical use the ASC obtained from fat isolated with the manual or the Bodyjet® water-jet-assisted procedure. Although the initial number of cells obtained after collagenase digestion was higher with the manual procedure, the percentage of dead cells, the number of colony forming unit-fibroblast and the phenotype of cells were identical in the SVF at isolation (day 0) and in the ASC populations at day 14. We also showed that the osteogenic and adipogenic differentiation potentials of ASCs were identical between preparations while a slight but significant higher in vitro immunosuppressive effect was observed with ASCs isolated from fat removed with a cannula. The difference in the immunomodulatory effect between ASC populations was, however, not observed in vivo using the delayed-type hypersensitivity (DTH) model. Our data, therefore, indicate that the procedure for fat liposuction does not impact the characteristics or the therapeutic function of ASCs. PMID:26834736

  16. Development of the SPIKE code for analysis of the sodium-water reaction

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Sung Tai; Park, Jin Ho; Choi, Jong Hyeun; Kim, Tae Joon [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-08-01

    In the secondary loop of liquid metal reactors, including SG, water leak into sodium causes the sudden increase of pressure by the H{sub 2} and heat generated from reaction. At few miliseconds after leak, a sharp and short-lived increase of pressure is generated and its propagation depends on the acoustic constraint characteristics of secondary loop. As increasing leak amount of water, another pressure increase is caused by H{sub 2} and its transients depends on the resistance of pressure opening system, such as rupture disc. For prediction of the transients of initial spike pressure, a code of SPIKE was developed. The code was based on the following simplifications and assumptions: combination of total and half release of H{sub 2} rate, spherical shape of H{sub 2} bubble, compressible and Newtonian fluid for sodium. The program was built in FOTRAN language and consisted of 5 modules. Several sample calculations were performed to test the code and to determine the scale down factor of experimental facilities for experimental verification of the code: parameter study of the variables in chemical reaction model, comparison study with results calculated by superposition methods for simple piping structures, comparison study with results calculated by previous researchers, and calculation for KALIMER models of various size. With these calculation results, the generally predicted phenomena of sodium water reaction can be explained and the calculated ones by SPIKE code were well agreed with the previous study. And the scale down factor can be determined. (author). 88 refs., 99 figs., 39 tabs.

  17. Simulation of a high-pressure water jet structure as an innovative tool for pulverizing copper ore in KGHM Polska Miedź S.A.

    Directory of Open Access Journals (Sweden)

    Przemysław Józef Borkowski

    2016-01-01

    Full Text Available Effective comminution of copper ore for further processing during flotation is still a challenge, both as a technological problem as well as for the high energy costs of such processing.A high-pressure water jet is one alternative method of preparing copper ore for final flotation, causing distinct enlargement of the surface of micronized particles, which could be profitable for copper production.As a consequence of such innovative processing, particles of copper ore become micronized, ensuring grain fractions directly useful for flotation at the exit of the pulverizing apparatus (the hydro-jetting mill.The paper presents some results of simulation as well as describing an analysis of the phenomena occurring inside the high-pressure water and abrasive-water jets of specific structures, elaborated in the aspect of developing hybrid jets of maximum erosive efficiency, potentially useful for effective pulverization.

  18. An Experimental Investigation of Ice Melting and Heat Transfer Characteristics from Submerged Jets of Hot Water, Implications for Subglacial Volcanic Eruptions

    Science.gov (United States)

    Jamshidnia, H.; Gudmundsson, M. T.

    2014-12-01

    The rates and processes of energy transfer in water-filled cavities formed under glaciers by geothermal and volcanic activity has been investigated by designing, developing, and using an experimental setup in which hot water jets can impinge on an ice block. Systematic sets of experimental runs typically lasting 60-90 seconds with water jet temperatures in the range 10° - 90°C have been performed with initial ice block temparature. It is quantitatively found that heat flux from flowing water to ice is linearly dependent on temperature of the jet flow. The hot water jet meltes out a cavity into the ice block during the process. The cavities had steep to vertical sides with a doming roof. Some of the ice blocks used had trapped air bubbles. In these cases melting of the ice lead to the trapping of air at the top of the cavity, partially insulating the roof from the hot water jet. Such cavities had lower aspect ratios (height/width) and flatter and less dome shaped roofs than did cavities in ice blocks with little or no air bubbles. The overall heat transfer rate in cavity formation varied with jet temperature from water in cool, subglacial water bodies and above subglacial flowpaths of jökulhlaups. However, the highest experimental rates for 80-90°C jets are 3-10 times less than inferred from observations of recent subglacial eruptions (2000-4000 kW m-2). This can indicate that single phase liquid water convection alone is not sufficient to explain the rates seen in recent subglacial eruptions in Iceland, suggesting that during such eruptions forced two-phase (liquid and steam) or three phase (liquid, steam and pyroclasts) convection is common. Further recommendations may also be presented for future research in this field.

  19. The evaluation of steam-water heat transfer in vertical channel using Trac code

    Energy Technology Data Exchange (ETDEWEB)

    Sang Won, Lee; Han Gon, Kim; Byong Sup, Kim; Seung, Jong [Korea Electric Power Co., Taejon (Korea, Republic of)

    2001-07-01

    The safety injection system(SIS) of the Korean Next Generation Reactor (KNGR) injects water into the reactor vessel directly for the effective usage of ECC water. The injection location is 83 inches higher than cold leg centerline. Due to this geometrical characteristics, during late reflood phase in large break LOCA, complicate thermal-hydraulic phenomena different from existing cold-leg injection plant could be occurred. Among these phenomena, the steam-water heat transfer is evaluated in this paper. We have selected TRAC code for the evaluation tool because it can handle the reactor vessel in three-dimensional coordinates and is has been validated using UPTF experiments. For this evaluation, we performed steam-water interaction experiments in vertical rectangular channel. The experiments have been performed for co-current and counter-current flow, various steam velocity, various water flow rate. Water is injected from the top of the channel as a thin film. Steam is injected from the top or the bottom of channel. All the experiments are performed in the condition of atmospheric pressure and that void fraction is ranged from 0.9 to 0.95. Therefore, it can be treated as annular-mist flow regime. TRAC model has been developed for the simulation of these experiments. As a result of simulation, it can be concluded that TRAC code predicts heat transfer coefficients as much as 10 times compared to experimental results. In order to correct these differences, we modified the heat transfer correlation for annular-mist flow in TRAC code. This modified correlation can be used heat transfer in the downcomer only. We will perform the larger break LOCA sensitivity analyses for the effect of heat transfer in the downcomer. (authors)

  20. The emergence of zonal jets in forced rotating shallow water turbulence: A laboratory study

    Science.gov (United States)

    Espa, S.; Di Nitto, G.; Cenedese, A.

    2010-11-01

    The emergence of a sequence of alternating intense and elongated eastward-westward bands i.e. zonal jets in the atmosphere of the giant planets and in Earth's oceans have been widely investigated. Nevertheless jets formation and role as material barriers remain still unclear. Jets are generated in a quasi-2D turbulent flow due to the latitudinal variation of the Coriolis parameter (the so-called β-effect) which modifies the inverse cascade process channeling energy towards zonal modes. In previous experiments we have investigated the impact of the variation of the rotation rate, of the domain geometry and of the initial spectra on jets organization in a decaying regime. In this work we investigate the formation of jets in a continuously forced flow, we characterize the observed regime and also we attempt to verify the existence of an universal regime corresponding to the so-called zonostrophic turbulence. The experimental set-up consists of a rotating tank where turbulence is generated by electromagnetically forcing a shallow layer of an electrolyte solution, and the variation of the Coriolis parameter has been simulated by the parabolic profile assumed by the free surface of the fluid under rotation. Flow measurements have been performed using image analysis.

  1. Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines: 1. Heterogeneous condensation of combustion products

    Science.gov (United States)

    Platov, Yu. V.; Semenov, A. I.; Filippov, B. V.

    2014-01-01

    Condensation of water vapor and carbon dioxide in the jet exhausts of rocket engines during last stages of Proton, Molniya, and Start launchers operating in the upper atmospheric with different types of fuels is considered. Particle heating is taken into account with emission of latent heat of condensation and energy loss due to radiation and heat exchange with combustion products. Using the solution of the heat balance and condensed particle mass equations, the temporal change in the temperature and thickness of the condensate layer is obtained. Practically, no condensation of water vapor and carbon dioxide in the jet exhaust of a Start launcher occurs. In plumes of Proton and Molniya launchers, the condensation of water vapor and carbon dioxide can start at distances of 120-170 m and 450-650 m from the engine nozzle, respectively. In the course of condensation, the thickness of the "water" layer on particles can exceed 100 Å, and the thickness of carbon dioxide can exceed 60 Å.

  2. Natural orifice transluminal endoscopic wedge hepatic resection with a water-jet hybrid knife in a non-survival porcine model

    Institute of Scientific and Technical Information of China (English)

    Hong Shi; Sheng-Jun Jiang; Bin Li; Deng-Ke Fu; Pei Xin; Yong-Guang Wang

    2011-01-01

    AIM:To explore the feasibility of a water-jet hybrid knife to facilitate wedge hepatic resection using a natural orifice transluminal endoscopic surgery (NOTES) approach in a non-survival porcine model.METHODS:The Erbe Jet2 water-jet system allows a needleless,tissue-selective hydro-dissection with a preselected pressure.Using this system,wedge hepatic resection was performed through three natural routes (trans-anal,trans-vaginal and trans-umbilical) in three female pigs weighing 35 kg under general anesthesia.Entry into the peritoneal cavity was via a 15-mm incision using a hook knife.The targeted liver segment was marked by an APC probe,followed by wedge hepatic resection performed using a water-jet hybrid knife with the aid of a 4-mm transparent distance soft cap mounted onto the tip of the endoscope for holding up the desired plane.The exposed vascular and ductal structures were clipped with Endoclips.Hemostasis was applied to the bleeding cut edges of the liver parenchyma by electrocautery.After the procedure,the incision site was left open,and the animal was euthanized followed by necropsy.RESULTS:Using the Erbe Jet2 water-jet system,transanal and trans-vaginal wedge hepatic resection was successfully performed in two pigs without laparoscopic assistance.Trans-umbilical attempt failed due to an unstable operating platform.The incision for peritoneal entry took 1 min,and about 2 h was spent on excision of the liver tissue.The intra-operative blood loss ranged from 100 to 250 mL.Microscopically,the hydro-dissections were relatively precise and gentle,preserving most vessels.CONCLUSION:The Erbe Jet2 water-jet system can safely accomplish non-anatomic wedge hepatic resection in NOTES,which deserves further studies to shorten the dissection time.

  3. Studies on parametric optimization for abrasive water jet machining of Al7075-TiB2 in-situ composite

    Science.gov (United States)

    Kavya, J. T.; Keshavamurthy, R.; Pradeep Kumar, G. S.

    2016-09-01

    The study focuses on optimization and determination of significant process parameter for Abrasive Water Jet Machining of Al7075-TiB2metal matrix composite. Al-TiB2 metal matrix composite is synthesized by stir casting using in-situ technique. Optimization of machining parameters is done using Taguchi's L25orthogonal array for the experimental trials, with cutting speed, stand-off distance and Abrasive Flow rate as input parameters at five different levels. Analysis Of Variance (ANOVA) method is used for identifying the effect of machining parameters on volumetric material removal rate, surface roughness and dimensional accuracy. Then the results are validated by conducting verification experiments.

  4. Water jet-assisted liposuction for patients with lipoedema: histologic and immunohistologic analysis of the aspirates of 30 lipoedema patients.

    Science.gov (United States)

    Stutz, J J; Krahl, D

    2009-03-01

    Lipoedema is a fat distribution disorder causing massive, bilaterally symmetrical enlargement of the lower and in some cases the upper extremities in women. The atraumatic, anatomically appropriate procedure of water jet-assisted liposuction available today represents a promising treatment for these patients who generally suffer from severe subjective and objective impairment. Liposuction treatment can bring long-term improvement if the operative technique focuses on lymph vessel preservation. Immunohistologic analyses show minimal evidence of lymph vessel structures in lipoaspirates. The histologic analysis of the aspirates documents a relatively specific removal ("apheresis") of primarily intact lipocytes with low vascular amount.

  5. Fabrication of Water Jet Resistant and Thermally Stable Superhydrophobic Surfaces by Spray Coating of Candle Soot Dispersion.

    Science.gov (United States)

    Qahtan, Talal F; Gondal, Mohammed A; Alade, Ibrahim O; Dastageer, Mohammed A

    2017-08-08

    A facile synthesis method for highly stable carbon nanoparticle (CNP) dispersion in acetone by incomplete combustion of paraffin candle flame is presented. The synthesized CNP dispersion is the mixture of graphitic and amorphous carbon nanoparticles of the size range of 20-50 nm and manifested the mesoporosity with an average pore size of 7 nm and a BET surface area of 366 m(2)g(-1). As an application of this material, the carbon nanoparticle dispersion was spray coated (spray-based coating) on a glass surface to fabricate superhydrophobic (water contact angle > 150° and sliding angle water jet resistance and thermal stability up to 400 °C compared to the surfaces fabricated from direct candle flame soot deposition (candle-based coating). This study proved that water jet resistant and thermally stable superhydrophobic surfaces can be easily fabricated by simple spray coating of CNP dispersion gathered from incomplete combustion of paraffin candle flame and this technique can be used for different applications with the potential for the large scale fabrication.

  6. Twin Jet

    Science.gov (United States)

    Henderson, Brenda; Bozak, Rick

    2010-01-01

    Many subsonic and supersonic vehicles in the current fleet have multiple engines mounted near one another. Some future vehicle concepts may use innovative propulsion systems such as distributed propulsion which will result in multiple jets mounted in close proximity. Engine configurations with multiple jets have the ability to exploit jet-by-jet shielding which may significantly reduce noise. Jet-by-jet shielding is the ability of one jet to shield noise that is emitted by another jet. The sensitivity of jet-by-jet shielding to jet spacing and simulated flight stream Mach number are not well understood. The current experiment investigates the impact of jet spacing, jet operating condition, and flight stream Mach number on the noise radiated from subsonic and supersonic twin jets.

  7. Influence of assistance of high-pressure water jet in the process of rock cutting upon the temperature, wear cutting force and dustiness of the shearer pick edge

    Energy Technology Data Exchange (ETDEWEB)

    Klich, A.; Kotwica, K.; Res, J. [University of Mining and Metallurgy, Cracow (Poland)

    1995-08-01

    The cutting of artificial samples of rock with and without cutting process assistance of a high-pressure water jet was investigated in the laboratory. During the research the temperature, pick edge wear, pressure and adjacent force and dustiness were measured under several selected mining parameters. The research used Rapid 85 shearer radial picks and the adjacent Alpine picks. The cutting with radial picks was assisted with a high-pressure water jet from the front and back whereas the adjacent picks cutting was assisted only from the front. For cutting with assistance of a high-pressure water jet the Saphintec type nozzles of d=0.3, 0.55 and 0.8 mm diameter and water pressure of p=1, 20, 40 and 60 MPa were used. 6 refs., 15 figs., 3 tabs.

  8. Light water reactor fuel analysis code FEMAXI-V (Ver.1)

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Motoe [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-09-01

    A light water fuel analysis code FEMAXI-V is an advanced version which has been produced by integrating FEMAXI-IV(Ver.2), high burn-up fuel code EXBURN-I, and a number of functional improvements and extensions, to predict fuel rod behavior in normal and transient (not accident) conditions. The present report describes in detail the basic theories and structure, models and numerical solutions applied, improvements and extensions, and the material properties adopted in FEMAXI-V(Ver.1). FEMAXI-V deals with a single fuel rod. It predicts thermal and mechanical response of fuel rod to irradiation, including FP gas release. The thermal analysis predicts rod temperature distribution on the basis of pellet heat generation, changes in pellet thermal conductivity and gap thermal conductance, (transient) change in surface heat transfer to coolant, using radial one-dimensional geometry. The heat generation density profile of pellet can be determined by adopting the calculated results of burning analysis code. The mechanical analysis performs elastic/plastic, creep and PCMI calculations by FEM. The FP gas release model calculates diffusion of FP gas atoms and accumulation in bubbles, release and increase in internal pressure of rod. In every analysis, it is possible to allow some materials properties and empirical equations to depend on the local burnup or heat flux, which enables particularly analysis of high burnup fuel behavior and boiling transient of BWR rod. In order to facilitate effective and wide-ranging application of the code, formats and methods of input/output of the code are also described, and a sample output in an actual form is included. (author)

  9. Testing of Alternative Abrasives for Water-Jet Cutting at C Tank Farm

    Energy Technology Data Exchange (ETDEWEB)

    Krogstad, Eirik J.

    2013-08-01

    Legacy waste from defense-related activities at the Hanford Site has predominantly been stored in underground tanks, some of which have leaked; others may be at risk to do so. The U.S. Department of Energy’s goal is to empty the tanks and transform their contents into more stable waste forms. To do so requires breaking up, and creating a slurry from, solid wastes in the bottoms of the tanks. A technology developed for this purpose is the Mobile Arm Retrieval System. This system is being used at some of the older single shell tanks at C tank farm. As originally planned, access ports for the Mobile Arm Retrieval System were to be cut using a high- pressure water-jet cutter. However, water alone was found to be insufficient to allow effective cutting of the steel-reinforced tank lids, especially when cutting the steel reinforcing bar (“rebar”). The abrasive added in cutting the hole in Tank C-107 was garnet, a complex natural aluminosilicate. The hardness of garnet (Mohs hardness ranging from H 6.5 to 7.5) exceeds that of solids currently in the tanks, and was regarded to be a threat to Hanford Waste Treatment and Immobilization Plant systems. Olivine, an iron-magnesium silicate that is nearly as hard as garnet (H 6.5 to 7), has been proposed as an alternative to garnet. Pacific Northwest National Laboratory proposed to test pyrite (FeS2), whose hardness is slightly less (H 6 to 6.5) for 1) cutting effectiveness, and 2) propensity to dissolve (or disintegrate by chemical reaction) in chemical conditions similar to those of tank waste solutions. Cutting experiments were conducted using an air abrader system and a National Institute of Standards and Technology Standard Reference Material (SRM 1767 Low Alloy Steel), which was used as a surrogate for rebar. The cutting efficacy of pyrite was compared with that of garnet and olivine in identical size fractions. Garnet was found to be most effective in removing steel from the target; olivine and pyrite were less

  10. Preliminary Development of Thermal Power Calculation Code H-Power for a Supercritical Water Reactor

    Directory of Open Access Journals (Sweden)

    Fan Zhang

    2014-01-01

    Full Text Available SCWR (Supercritical Water Reactor is one of the promising Generation IV nuclear systems, which has higher thermal power efficiency than current pressurized water reactor. It is necessary to perform the thermal equilibrium and thermal power calculation for the conceptual design and further monitoring and calibration of the SCWR. One visual software named H-Power was developed to calculate thermal power and its uncertainty of SCWR, in which the advanced IAPWS-IF97 industrial formulation was used to calculate the thermodynamic properties of water and steam. The ISO-5167-4: 2003 standard was incorporated in the code as the basis of orifice plate to compute the flow rate. New heat balance model and uncertainty estimate have also been included in the code. In order to validate H-Power, an assessment was carried out by using data published by US and Qinshan Phase II. The results showed that H-Power was able to estimate the thermal power of SCWR.

  11. The effect of water injection on nitric oxide emissions of a gas turbine combustor burning ASTM Jet-A fuel

    Science.gov (United States)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    Tests were conducted to determine the effect of water injection on oxides of nitrogen (NOx) emissions of a full annular, ram induction gas turbine combustor burning ASTM Jet-A fuel. The combustor was operated at conditions simulating sea-level takeoff and cruise conditions. Water at ambient temperature was injected into the combustor primary zone at water-fuel ratios up to 2. At an inlet-air temperature of 589 K (600 F) water injection decreased the NOx emission index at a constant exponential rate: NOx = NOx (o) e to the -15 W/F power (where W/F is the water-fuel ratio and NOx(o) indicates the value with no injection). The effect of increasing combustor inlet-air temperature was to decrease the effect of the water injection. Other operating variables such as pressure and reference Mach number did not appear to significantly affect the percent reduction in NOx. Smoke emissions were found to decrease with increasing water injection.

  12. Dermal microvasculature and tissue selective thinning techniques (ultrasound and water-jet) of short-time expanded skin in dogs.

    Science.gov (United States)

    Siegert, R; Danter, J; Jurk, V; Eggers, R; Krüger, S

    1998-01-01

    Certain reconstructive procedures, like auricular reconstructions, require thin and well-vascularized skin. The aims of this study were to analyze if the increased survival of expanded skin flaps was due to morphologic changes of the dermis, if thinning of short-time expanded skin was possible without harm to the microcirculation and if tissue selective cutting methods could be used to resect subcutaneous fat without damaging its vessels. Eighty-two 200-ml expanders were implanted into the trunk regions of 26 beagles and filled immediately with sterile saline. In the first series of experiments, the expansion was terminated after intervals of 0.5-5 weeks and dermal vessels were analyzed morphometrically. In the second series the expanded flaps were raised after 2 weeks and thinned solely surgically or with the additional use of an ultrasonic knife or with cutting by water jet. In contrast to sham flaps, the expanded skin showed only very few areas of necrosis and these were located superficially in most cases. The relative volume of the dermal vessels and their quantity showed a significant increase after the expansion. Additionally, the subcutaneous tissue could be thinned down to 0.4 mm with the water-jet-cutter. Findings demonstrated that the method used could create a well-vascularized skin flap of minimal thickness that could be very helpful for special reconstructive procedures.

  13. Fragmentation of bile duct stones: a prospective systematic in vitro evaluation of argon plasma coagulation, cryotechnology, and water-jet technology.

    Science.gov (United States)

    Eickhoff, A; Koberstein, S; Rothsching, M; Gemmel, C; Eickhoff, J C; Riemann, J F; Enderle, M D

    2009-08-01

    Choledocholithiasis is a common disease in the West. Lithotripsy by mechanical methods using baskets and by laser or electrohydraulic methods varies in effectiveness. With argon plasma coagulation (APC), high temperatures are used for devitalization and fragmentation; cryogenic techniques use the selective controlled application of freeze-thaw cycles to devitalize pathological tissue; and the dissecting water jet exploits the high pressure action of a thin laminar jet. We aimed to assess the feasibility and effectiveness of APC, cryotechnology, and the dissecting water jet as options for the fragmentation of bile duct stones. In an in vitro feasibility study, we evaluated the fragmentation of 120 bile duct stones treated with the three methods. Primary measures were assessment of the fragmentation rate, fragmentation effect, and energy application for each technology. Fragmentation was seen in only 10 % of stones treated cryogenically using liquid nitrogen. APC at a power setting of 30 - 50 W fragmented all the cholesterol stones, but results with hard pigment stones were unsatisfactory even at high energies of a 100 W setting and long application time. Using the water jet, all 40 stones (100 %) were cracked effectively and completely with a pressure of 10 - 50 bar. In this feasibility study, the first of its kind, only the water-jet device demonstrated efficient fragmentation of large bile duct stones in vitro. APC and cryotechnology are not suitable for the treatment of bile duct stones; the fragmentation rate with these methods was inadequate.

  14. Taguchi versus Full Factorial Design to Determine the Influence of Process Parameters on the Impact Forces Produced by Water Jets Used in Sewer Cleaning

    Science.gov (United States)

    Medan, N.; Banica, M.

    2016-11-01

    The regular cleaning of the materials deposed in sewer networks is realized, especially with equipment that uses high pressure water jets. The functioning of this equipment is dependent on certain process parameters that can vary, causing variations of the impact forces. The impact force directly affects the cleaning of sewer systems. In order to determine the influence of the process parameters on the impact forces produced by water jets the method of research used is the experiment. The research methods used is that Taguchi design and full factorial design. For the experimental determination of the impact forces a stand for generating water jets and a device for measuring the forces of impact are used. The processing of data is carried out using the Software Minitab 17.

  15. Construção de um sistema simples e compacto de recirculação d'água sob pressão para trompa d'água Construction of a simple and compact system to recirculate water under pressure using a water-jet aspira tor pump

    Directory of Open Access Journals (Sweden)

    Dennis de Oliveira Imbroisi

    2009-01-01

    Full Text Available Vacuum pumps are very useful in physical, chemical and biological experiments. In this communication it is described the design of a compact and low cost water recirculating system employing a water-jet aspirator pump as the vacuum source. The system requires only a water pump, water-jet aspirator pump, commercial PVC water tubes and a drain connection.

  16. High-speed cutting of thin materials with a Q-switched laser in a water-jet versus conventional laser cutting with a free running laser

    Science.gov (United States)

    Wagner, Frank R.; Boillat, Christophe; Buchilly, Jean-Marie; Spiegel, Akos; Vago, Nandor; Richerzhagen, Bernold

    2003-07-01

    Cutting of thin material, c.f. stencils, stents and thin wafers, is an important market for laser machining. Traditionally this task is performed using flash-lamp pumped, free-running Nd:YAG lasers. Using the water-jet guided laser technology, we experienced that the use of Q-switched lasers leads to superior results while cutting a variety of thin materials. In this technique, the laser is conducted to the work piece by total internal reflection in a thin stable water-jet, comparable to the core of an optical fiber. Utilizing this system, we obtain burr-free, slightly tapered cuts at the same speed as the classical laser cutting and without distinguishable heat affected zone. The main difference is, except the water-jet usage, the pulse duration which is approximately 400 ns instead of 20 to 200 μs in the case of free running lasers. Up to 40'000 high quality apertures per hour can be achieved in stencil mask cutting with the new system. We will compare qualitatively the two possibilities: conventional laser cutting with free-running lasers and water-jet guided laser cutting with Q-switched lasers. The results will be discussed in terms of the different physical effects involved in the material removal upon both methods. In particular the importance of molten material expulsion by the water-jet will be pointed out and compared to the action of the assist-gas. The mentioned effects show that the combination of short pulse laser and water-jet will be beneficial for the production of a wide range of precision parts.

  17. 水射流辅助截齿破碎钴结壳%Cobalt Crusts Fractured by Cutter and Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄中华; 谢雅

    2011-01-01

    建立了水射流辅助截齿破碎钴结壳的力学模型,通过仿真研究获取了水射流系统参数与截齿在钴结壳表面切出初始裂纹所需最小破碎力的作用规律.仿真结果表明:当水射流的作用点和截齿的作用点不. 重合时,水射流的辅助破碎不仅不能减小截齿所需的破碎力,反而会增加截齿所需的破碎力;当水射流的作用点和截齿的作用点重合时,水射流的辅助破碎能有效减小截齿所需的破碎力;与纯截齿破碎钴结壳相比,当水射流的压力为5 MPa时,截齿所需的破碎力下降幅度约为50%;随着水射流系统工作压力的增加,水射流系统的辅助破碎作用越强.%Mechanical model of fracturing the cobalt crusts by cutter and water jet was established. With simulation study, the relationship between water jet system parameters and cutter's minimum cutting force was obtained, which was needed to generate initial crack on cobalt crust surface. Simulation results show that when the working point of both water jet and cutter isn't overlap, water jet can't decrease cutter's minimum cutting force. Conversely, it will increase cutter's minimum cutting force. When water jet working point is overlap with cutter working point, water jet can decrease cutter's minimum cutting force obviously. Compared with cutter cutting alone, when water jet pressure is 5 Mpa, cutter's minimum cutting force is reduced by 50%. With water jet working pressure increasing, cutter's minimum cutting force is decreased correspondingly.

  18. An Experimental Investigation of Ice-melting and heat transfer rates from submerged warm water jets upward impinging into ice-blocks as analogous for water-filled cavities formed during subglacial eruptions.

    Science.gov (United States)

    Jamshidnia, Hamidreza; Gudmundsson, Magnus Tumi

    2016-11-01

    Rates of energy transfer in water-filled cavities formed under glaciers by geothermal and volcanic activity are investigated by conducting experiments in which hot water jets (10°- 90°C) impinging into an ice block for jet Reynolds numbers in turbulent regime of 10000 -70000. It is found that heat flux is linearly dependent on jet flow temperature. Water jet melts a cavity into an ice block. Cavities had steep to vertical sides with a doming roof. Some of ice blocks used had trapped air bubbles. In these cases that melting of the ice could have led to trapping of air at the top of cavity, partially insulating the roof from hot water jet. The overall heat transfer rate in cavity formation varied with jet temperature from <100 kW m-2 to 900 kW m-2 while melting rates in the vertical direction yield heat transfer rates of 200-1200 kW m-2. Experimental heat transfer rates can be compared to data on subglacial melting observed for ice cauldrons in Iceland. For lowest temperatures the numbers are comparable to those for geothermal water in cool, subglacial water bodies and above subglacial flowpaths of jökulhlaups. Highest experimental rates for 80-90°C jets are 3-10 times less than inferred from observations of recent subglacial eruptions (2000-4000 kW m-2) . This can indicate that single phase liquid water convection alone may not be sufficient to explain the rates seen in recent subglacial eruptions, suggesting that forced 2 or 3 phase convection can be common.

  19. Measuring magnetic fields from water masers in the synchrotron protostellar jet in W3(H2O)

    Science.gov (United States)

    Goddi, C.; Surcis, G.; Moscadelli, L.; Imai, H.; Vlemmings, W. H. T.; van Langevelde, H. J.; Sanna, A.

    2017-01-01

    strength in the range 100-300 mG (at densities of 109 cm-3). We conclude that fields of this order of magnitude are expected if the observed polarized water masers emerge behind magnetically supported shocks which, propagating in the W3(H2O) hot core (with an initial density of order of 107 cm-3), compress and enhance the field component perpendicular to the shock velocity (with an initial field strength of a few mG). We constrain the magnetic field strength in the pre-shock circumstellar gas (which is dominated by the component parallel to the flow motion) to at least 10-20 mG (at densities of 107 cm-3), consistent with previous estimates from a synchrotron jet model and dust polarization measurements. Conclusions: In W3(H2O), the magnetic field would evolve from having a dominant component parallel to the outflow velocity in the pre-shock gas, with field strengths of the order of a few tens of mG, to being mainly dominated by the perpendicular component of order of a few hundred of mG in the post-shock gas where the H2O masers are excited. The general implication is that in the undisturbed (i.e., not-shocked) circumstellar gas, the flow velocities would follow closely the magnetic field lines, while in the shocked gas the magnetic field would be reconfigured to be parallel to the shock front.

  20. 射水泵抽气器改造的经济性评价%Economic Evaluation for Water Jet air Ejector Transformation

    Institute of Scientific and Technical Information of China (English)

    杨黎斌

    2014-01-01

    It introduced TD-N12 water jet ejector device configuration and work principle. Based on analysis: change the old single channel water jet air ejector condenser to multi-channel water jet air ejector condenser, under condition of declined pumping water, it choose small power water jet pump motor to save energy and water. After energy saving renovation, water jet air ejector power has become 20.4kw from 28.8kw. according to 6700 hours operation time in 2013, it could save 56.28mwh, which equals 28.4 ton coal, 23000rmb. Good energy saving effect has been archieved.%介绍了TD-N12射水泵抽气器的设备配置及工作原理。通过分析得出:将老式单通道射水凝汽器改为多通道射水凝汽器,在抽水总量下降的状况下选用小功率射水泵电机,可达到节水和节电效果。节能改造证实射水抽气器实施改造后,配套电机实际功率由原来的28.8 kW降至20.4kW。以2013年机组运行6700 h计算,节约用电量56.28 MWh,节约标煤量28.4t,节省燃料成本2.3万元,取得了较好的节能效果。

  1. Jet observables without jet algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Daniele; Chan, Tucker; Thaler, Jesse [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA 02139 (United States)

    2014-04-02

    We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but like a jet clustering algorithm, they incorporate a jet radius parameter and a transverse momentum cut. Three of the ubiquitous jet-based observables — jet multiplicity, summed scalar transverse momentum, and missing transverse momentum — have event shape counterparts that are closely correlated with their jet-based cousins. Due to their “local” computational structure, these jet-like event shapes could potentially be used for trigger-level event selection at the LHC. Intriguingly, the jet multiplicity event shape typically takes on non-integer values, highlighting the inherent ambiguity in defining jets. By inverting jet multiplicity, we show how to characterize the transverse momentum of the n-th hardest jet without actually finding the constituents of that jet. Since many physics applications do require knowledge about the jet constituents, we also build a hybrid event shape that incorporates (local) jet clustering information. As a straightforward application of our general technique, we derive an event-shape version of jet trimming, allowing event-wide jet grooming without explicit jet identification. Finally, we briefly mention possible applications of our method for jet substructure studies.

  2. Theoretical Analysis and Experimental Study on the Coating Removal from Passenger-Vehicle Plastics for Recycling by Using Water Jet Technology

    Science.gov (United States)

    Zhang, Hongshen; Chen, Ming

    2015-11-01

    The recovery and utilization of automotive plastics are a global concern because of the increasing number of end-of-life vehicles. In-depth studies on technologies for the removal of coatings from automotive plastics can contribute to the high value-added levels of the recycling and utilization of automotive plastic. The liquid waste generated by removing chemical paint by using traditional methods is difficult to handle and readily produces secondary pollution. Therefore, new, clean, and highly efficient techniques of paint removal must be developed. In this article, a method of coating removal from passenger-vehicle plastics was generated based on high-pressure water jet technology to facilitate the recycling of these plastics. The established technology was theoretically analyzed, numerically simulated, and experimentally studied. The high-pressure water jet equipment for the removal of automotive-plastic coatings was constructed through research and testing, and the detailed experiments on coating removal rate were performed by using this equipment. The results showed that high-pressure water jet technology can effectively remove coatings on the surfaces of passenger-vehicle plastics. The research also revealed that the coating removal rate increased as jet pressure ( P) increased and then decreased when jet moving speed ( Vn) increased. The rate decreased as the distance from nozzle to work piece ( S nw ) and the nozzle angle ( Φ) increased. The mathematical model for the rate of removal of coatings from bumper surfaces by water jet was derived based on the experiment data and can effectively predict coating removal rate under different operating conditions.

  3. Benchmarking of a New Finite Volume Shallow Water Code for Accurate Tsunami Modelling

    Science.gov (United States)

    Reis, Claudia; Clain, Stephane; Figueiredo, Jorge; Baptista, Maria Ana; Miranda, Jorge Miguel

    2015-04-01

    Finite volume methods used to solve the shallow-water equation with source terms receive great attention on the two last decades due to its fundamental properties: the built-in conservation property, the capacity to treat correctly discontinuities and the ability to handle complex bathymetry configurations preserving the some steady-state configuration (well-balanced scheme). Nevertheless, it is still a challenge to build an efficient numerical scheme, with very few numerical artifacts (e.g. numerical diffusion) which can be used in an operational environment, and are able to better capture the dynamics of the wet-dry interface and the physical phenomenon that occur in the inundation area. We present here a new finite volume code and benchmark it against analytical and experimental results, and we test the performance of the code in the complex topographic of the Tagus Estuary, close to Lisbon, Portugal. This work is funded by the Portugal-France research agreement, through the research project FCT-ANR/MAT-NAN/0122/2012.

  4. The dissection profile and mechanism of tissue-selective dissection of the piezo actuator-driven pulsed water jet as a surgical instrument: laboratory investigation using Swine liver.

    Science.gov (United States)

    Yamada, Masato; Nakano, Toru; Sato, Chiaki; Nakagawa, Atsuhiro; Fujishima, Fumiyoshi; Kawagishi, Naoki; Nakanishi, Chikashi; Sakurai, Tadashi; Miyata, Go; Tominaga, Teiji; Ohuchi, Noriaki

    2014-01-01

    The water jet technique dissects tissue while sparing cord-like structures such as blood vessels. The mechanism of such tissue-selective dissection has been unknown. The novel piezo actuator-driven pulsed water jet (ADPJ) system can achieve dissection with remarkably reduced water consumption compared to the conventional water jet; however, the system's characteristics and dissection capabilities on any organ have not been clarified. The purposes of this study were to characterize the physical properties of the novel ADPJ system, evaluate the dissection ability in swine organs, and reveal the mechanism of tissue-selective dissection. The pulsed water jet system comprised a pump chamber driven by a piezo actuator, a stainless steel tube, and a nozzle. The peak pressure of the pulsed water jet was measured through a sensing hole using a pressure sensor. The pulsed water jet technique was applied on swine liver in order to dissect tissue on a moving table using one-way linear ejection at a constant speed. The dissection depth was measured with light microscopy and evaluated histologically. The physical properties of swine liver were evaluated by breaking strength tests using tabletop universal testing instruments. The liver parenchyma was also cut with three currently available surgical devices to compare the histological findings. The peak pressure of the pulsed water jet positively correlated with the input voltage (R(2) = 0.9982, p dissection depth. The dissection depth negatively correlated with the breaking strength of the liver parenchyma (R(2) = 0.6694, p dissected, preserving the hepatic veins and Glisson's sheaths in contrast to what is commonly observed with electrocautery or ultrasonic instruments. The dissection depth of liver tissue is well controlled by input voltage and is influenced by the moving velocity and the physical properties of the organ. We showed that the device can be used to assure liver resection with tissue selectivity due to tissue

  5. Achieving Small Structures in Thin NiTi Sheets for Medical Applications with Water Jet and Micro Machining: A Comparison

    Science.gov (United States)

    Frotscher, M.; Kahleyss, F.; Simon, T.; Biermann, D.; Eggeler, G.

    2011-07-01

    NiTi shape memory alloys (SMA) are used for a variety of applications including medical implants and tools as well as actuators, making use of their unique properties. However, due to the hardness and strength, in combination with the high elasticity of the material, the machining of components can be challenging. The most common machining techniques used today are laser cutting and electrical discharge machining (EDM). In this study, we report on the machining of small structures into binary NiTi sheets, applying alternative processing methods being well-established for other metallic materials. Our results indicate that water jet machining and micro milling can be used to machine delicate structures, even in very thin NiTi sheets. Further work is required to optimize the cut quality and the machining speed in order to increase the cost-effectiveness and to make both methods more competitive.

  6. Light water reactor fuel analysis code FEMAXI-IV(Ver.2). Detailed structure and user`s manual

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Motoe [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Saitou, Hiroaki

    1997-11-01

    A light water reactor fuel behavior analysis code FEMAXI-IV(Ver.2) was developed as an improved version of FEMAXI-IV. Development of FEMAXI-IV has been already finished in 1992, though a detailed structure and input manual of the code have not been open to users yet. Here, the basic theories and structure, the models and numerical solutions applied to FEMAXI-IV(Ver.2), and the material properties adopted in the code are described in detail. In FEMAXI-IV(Ver.2), programming bugs in previous FEMAXI-IV were eliminated, renewal of the pellet thermal conductivity was performed, and a model of thermal-stress restraint on FP gas release was incorporated. For facilitation of effective and wide-ranging application of the code, methods of input/output of the code are also described in detail, and sample output is included. (author)

  7. The International Code for Ships Operating in Polar Waters: Finalization, Adoption and Law of the Sea Implications

    Directory of Open Access Journals (Sweden)

    Øystein Jensen

    2016-05-01

    Full Text Available The most recent instrument specifically designed to make navigation in polar waters safer and more environmentally friendly is the International Maritime Organization's long-awaited “International Code for Ships Operating in Polar Waters” – the Polar Code. This article first briefly examines the legislative history of the Code, with emphasis on the final and consolidating phase of development. Second, an account is provided of the main contents of the Code as regards its regulations on safety measures and pollution prevention. Finally, the analysis places the new framework in the broader context of international law, including an examination of the Polar Code's relationship to specific provisions and legislative arrangements of the United Nations Convention on the Law of the Sea.

  8. Thermal-hydraulic analysis of a heavy-water reactor moderator tank using the CUPID Code

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Su Ryong; Jeong, Jae Jun [Pusan National Univ., Busan (Korea, Republic of); Kim, Hyoung Tae; Yoon, Han Young [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In this study, a preliminary analysis is performed for the CANDU moderator tank. The calculation results using the basic case input showed a unrealistic, thermal stratification in the upper region, which was caused by the lack of the momentum of the cooling water from the inlet nozzle. To increase the flow momentum from the inlet nozzle, the cross-section area of each inlet nozzle was reduced by half and, then, the calculation showed very realistic results. It is clear that the modeling of the inlet nozzle affects the calculation result significantly. Further studies are needed for a realistic and efficient simulation of the flow in the Calandria tank. When the core cooling system fails to remove the decay heat from the fuel channels during a loss of coolant accident (LOCA), the pressure tube (PT) could strain to contact its surrounding Calandria tube (CT), which leads to sustained CTs dry out, finally resulting in damages to nuclear fuel. This situation can occur when the degree of the subcooling of the moderator inside the Calandria vessel is insufficient. In this regard, to estimate the local subcooling of the moderator inside the Calandria vessel is very important. However, the local temperature is measured at the inlet and outlet of the vessel only. Therefore, we need to accurately predict the local temperature inside the Calandria vessel.In this study, the thermal-hydraulic analysis of the real-scale heavy-water reactor moderator is carried out using the CUPID code. The applicability of the CUPID code to the analysis of the flow in the Calandria vessel has been assessed in the previous studies.

  9. Abrasive water jet cutting as a new procedure for cutting cancellous bone--in vitro testing in comparison with the oscillating saw.

    Science.gov (United States)

    Schwieger, Karsten; Carrero, Volker; Rentzsch, Reemt; Becker, Axel; Bishop, Nick; Hille, Ekkehard; Louis, Hartmut; Morlock, Michael; Honl, Matthias

    2004-11-15

    The quality of bone cuts is assessed by the accuracy and biological potency of the cut surfaces. Conventional tools (such as saws and milling machines) can cause thermal damage to bone tissue. Water jet cutting is nonthermal; that is, it does not generate heat. This study investigates whether the abrasive jet cutting quality in cancellous bone with a biocompatible abrasive is sufficient for the implantation of endoprostheses or for osteotomies. Sixty porcine femoral condyles were cut with an abrasive water jet and with an oscillating saw. alpha-lactose-monohydrate was used as a biocompatible abrasive. Water pressure (pW = 35 and 70 MPa) and abrasive feed rate (m = 0.5, 1, and 2 g/s) were varied. As a measure of the quality of the cut surface the cutting gap angle (delta) and the surface roughness (Ra) were determined. The surface roughness was lowest for an abrasive feed rate of m = 2 g/s (jet direction: 39 +/- 16 microm, advance direction: 54 +/- 22 microm). However, this was still significantly higher than the surface roughness for the saw group (jet direction: 28 +/- 12 microm, advance direction: 36 +/- 19 microm) (p cutting gap angle was observed for a mass flow rate of m = 1 g/s (pW = 35 MPa: delta = 2.40 +/- 4.67 degrees ; pW = 70 MPa: delta = 4.13 +/- 4.65 degrees), which was greater than for m = 0.5 g/s (pW = 35 MPa: delta = 1.63 +/- 3.89 degrees ; pW = 70 MPa: delta = 0.36 +/- 1.70 degrees) and m = 2 g/s (pW =70 MPa: delta = 0.06 +/- 2.40 degrees). Abrasive water jets are suitable for cutting cancellous bone. The large variation of the cutting gap angle is, however, unfavorable, as the jet direction cannot be adjusted by a predefined value. If it is possible to improve the cutting quality by a further parameter optimization, the abrasive water jet may be the cutting technique of the future for robotic usage.

  10. Comparative study of Thermal Hydraulic Analysis Codes for Pressurized Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yang Hoon; Jang, Mi Suk; Han, Kee Soo [Nuclear Engineering Service and Solution Co. Ltd., Daejeon (Korea, Republic of)

    2015-05-15

    Various codes are used for the thermal hydraulic analysis of nuclear reactors. The use of some codes among these is limited by user and some codes are not even open to general person. Thus, the use of alternative code is considered for some analysis. In this study, simple thermal hydraulic behaviors are analyzed using three codes to show that alternative codes are possible for the analysis of nuclear reactors. We established three models of the simple u-tube manometer using three different codes. RELAP5 (Reactor Excursion and Leak Analysis Program), SPACE (Safety and Performance Analysis CodE for nuclear power Plants), GOTHIC (Generation of Thermal Hydraulic Information for Containments) are selected for this analysis. RELAP5 is widely used codes for the analysis of system behavior of PWRs. SPACE has been developed based on RELAP5 for the analysis of system behavior of PWRs and licensing of the code is in progress. And GOTHIC code also has been widely used for the analysis of thermal hydraulic behavior in the containment system. The internal behavior of u-tube manometer was analyzed by RELAP5, SPACE and GOTHIC codes. The general transient behavior was similar among 3 codes. However, the stabilized status of the transient period analyzed by REPAP5 was different from the other codes. It would be resulted from the different physical models used in the other codes, which is specialized for the multi-phase thermal hydraulic behavior analysis.

  11. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-05-01

    This document was written to provide guidance to managers and site operators on how ground-water transport codes should be selected for assessing burial site performance. There is a need for a formal approach to selecting appropriate codes from the multitude of potentially useful ground-water transport codes that are currently available. Code selection is a problem that requires more than merely considering mathematical equation-solving methods. These guidelines are very general and flexible and are also meant for developing systems simulation models to be used to assess the environmental safety of low-level waste burial facilities. Code selection is only a single aspect of the overall objective of developing a systems simulation model for a burial site. The guidance given here is mainly directed toward applications-oriented users, but managers and site operators need to be familiar with this information to direct the development of scientifically credible and defensible transport assessment models. Some specific advice for managers and site operators on how to direct a modeling exercise is based on the following five steps: identify specific questions and study objectives; establish costs and schedules for achieving answers; enlist the aid of professional model applications group; decide on approach with applications group and guide code selection; and facilitate the availability of site-specific data. These five steps for managers/site operators are discussed in detail following an explanation of the nine systems model development steps, which are presented first to clarify what code selection entails.

  12. Parameters design of cobalt crusts water jet cutting system%钴结壳水射流切削系统参数设计

    Institute of Scientific and Technical Information of China (English)

    黄中华; 谢雅

    2012-01-01

    Deep sea cobalt crusts water jet cutting method is proposed to avoid the impact load, which is generated during cutter cutting cobalt crusts. With simulation calculations and experimental tests, water jet system parameters and its cutting ability were stud-ied. Simulation results show that working pressure, injection range and injection angle of water jet system are main parameters to its cutting ability. Its important degree is in turn the working pressure, injection range and injection angle. To increase water jet system working pressure is the most effective way to improve its cutting a-bility. When working pressure is constant, in order to improve wa-ter jet cutting ability, the injection range should be less than 4 mm (four times of nozzle diameter) and injection angle should be about 13° Experimental results show that increasing water jet working pressure can dramatically improve its cutting ability, decreasing in-jection range can improve water jet cutting ability. The optimal in-jection angle is about 13°%为了避免刀具切削钴结壳时产生冲击载荷,提出了深海钴结壳水射流切削方法.采用仿真计算和实验测试研究了水射流系统参数与其切削性能的作用规律.仿真结果表明:水射流系统的工作压力、喷距和喷射角度是决定水射流切削能力的主要参数;其重要程度依次为工作压力、喷距和喷射角度;提高水射流系统工作压力是提高射流切削能力最有效的方法;在射流工作压力一定的情况下,为了提高射流的切削能力,射流的喷距宜小于4 mm(4倍喷嘴直径)内,射流的喷射角度约为13°.实验结果表明:提高射流的工作压力可以显著提高射流的切削能力,减小射流的喷距有助于提高射流的切削能力,射流的最优喷射角度约为13°.

  13. Experimental and Thermalhydraulic Code Assessment of the Transient Behavior of the Passive Condenser System in an Advanced Boiling Water Reactor

    Energy Technology Data Exchange (ETDEWEB)

    S.T. Revankar; W. Zhou; Gavin Henderson

    2008-07-08

    The main goal of the project was to study analytically and experimentally the condensation heat transfer for the passive condenser system such as GE Economic Simplified Boiling Water Reactor (ESBWR). The effect of noncondensable gas in condenser tube and the reduction of secondary pool water level to the condensation heat transfer coefficient was the main focus in this research. The objectives of this research were to : 1) obtain experimental data on the local and tube averaged condensation heat transfer rates for the PCCS with non-condensable and with change in the secondary pool water, 2) assess the RELAP5 and TRACE computer code against the experimental data, and 3) develop mathematical model and ehat transfer correlation for the condensation phenomena for system code application. The project involves experimentation, theoretical model development and verification, and thermal- hydraulic codes assessment.

  14. Numerical thermal-hydraulics study on sodium-water phenomena. Development of computational code 'SERAPHIM'

    Energy Technology Data Exchange (ETDEWEB)

    Takata, Takashi; Yamaguchi, Akira [Japan Nuclear Cycle Development Inst., Oarai, Ibaraki (Japan). Oarai Engineering Center

    2002-12-01

    A multi-component and multi-phase numerical analysis method is developed to investigate a mechanism of sodium-water reaction phenomena, which occur when pressurized water leaks from failed heat transfer tubes in the steam generator of a fast reactor. It is named SERAPHIM: Sodium-watEr Reaction Analysis PHysics of Interdisciplinary Multi-phase flow. In this code, the surface reaction model and the gas phase reaction model are implemented as a sodium-water reaction mechanism. The HSMAC method is adopted for numerical solution. A validation for compressible multi-phase flow analysis is carried out in the present paper. Two-dimensional analyses of the sodium-water reaction are also carried out and it is demonstrated that the numerical quantification of a sodium-water reaction accident by the SERAPHIM code is practicable. (author)

  15. A case of quinsy following high-pressure water jet injury.

    Science.gov (United States)

    Fitzgerald, C; Oosthuizen, J C; O'Dwyer, T

    2014-06-01

    High-pressure water injuries of the oropharynx are uncommon but can cause significant injury and airway compromise when they occur. A small number of cases of high-pressure water injury of the oropharynx have been presented in the literature, detailing a range of effects and outcomes. We describe the first reported case of high-pressure water injury of the oropharynx associated with peritonsillar abscess (quinsy) requiring surgical drainage.

  16. High Velocity Precessing Jets from the Water Fountain IRAS 18286-0959 Revealed by VLBA Observations

    OpenAIRE

    Yung, Bosco; Nakashima, Jun-ichi; Imai, Hiroshi; Deguchi, Shuji; Diamond, Philip; Kwok, Sun

    2011-01-01

    We report the results of multi-epoch VLBA observations of the 22.2GHz water maser emission associated with the "water fountain" IRAS 18286-0959. We suggest that this object is the second example of a highly collimated bipolar precessing outflow traced by water maser emission, the other is W43A. The detected water emission peaks are distributed over a velocity range from -50km/s to 150km/s. The spatial distribution of over 70% of the identified maser features is found to be highly collimated a...

  17. Comparison of pulsating DC and DC power air-water plasma jet: A method to decrease plume temperature and increase ROS

    Science.gov (United States)

    Liu, K.; Hu, H.; Lei, J.; Hu, Y.; Zheng, Z.

    2016-12-01

    Most air-water plasma jets are rich in hydroxyl radicals (•OH), but the plasma has higher temperatures, compared to that of pure gas, especially when using air as working gas. In this paper, pulsating direct current (PDC) power was used to excite the air-water plasma jet to reduce plume temperature. In addition to the temperature, other differences between PDC and DC plasma jets are not yet clear. Thus, comparative studies of those plasmas are performed to evaluate characteristics, such as breakdown voltage, temperature, and reactive oxygen species. The results show that the plume temperature of PDC plasma is roughly 5-10 °C lower than that of DC plasma in the same conditions. The •OH content of PDC is lower than that of DC plasma, whereas the O content of PDC plasma is higher. The addition of water leads in an increase in the plume temperature and in the production of •OH with two types of power supplies. The production of O inversely shows a declining tendency with higher water ratio. The most important finding is that the PDC plasma with 100% water ratio achieves lower temperature and more abundant production of •OH and O, compared with DC plasma with 0% water ratio.

  18. Accelerating a water maser face-on jet from a high mass young stellar object

    Science.gov (United States)

    Motogi, Kazuhito; Sorai, Kazuo; Honma, Mareki; Hirota, Tomoya; Hachisuka, Kazuya; Niinuma, Kotaro; Sugiyama, Koichiro; Yonekura, Yoshinori; Fujisawa, Kenta

    2016-10-01

    We report on long-term single-dish and VLBI monitoring for intermittent flare activities of a dominant blue-shifted H2O maser associated with a southern high mass young stellar object, G353.273+0.641. Bi-weekly single-dish monitoring using the Hokkaido University Tomakomai 11 m radio telescope has shown that a systematic acceleration continues over four years beyond the lifetime of individual maser features. This fact suggests that the H2O maser traces a region where molecular gas is steadily accelerated. There were five maser flares during the five years of monitoring, and maser distributions in four of them were densely monitored by VLBI Exploration of Radio Astrometry (VERA). The overall distribution of the maser features suggests the presence of a bipolar jet, with the 3D kinematics indicating that it is almost face-on (inclination angle of ˜ 8°-17° from the line of sight). Most maser features were recurrently excited within a region of 100×100 au2 around the radio continuum peak, while their spatial distributions significantly varied between each flare. This confirms that episodic propagations of outflow shocks recurrently invoke intermittent flare activities. We also measured annual parallax, deriving a source distance of 1.70^{+0.19}_{-0.16} kpc that is consistent with the commonly used photometric distance.

  19. Accelerating an Water Maser Face-on Jet from a High Mass Young Stellar Object

    CERN Document Server

    Motogi, Kazuhito; Honma, Mareki; Hirota, Tomoya; Hachisuka, Kazuya; Niinuma, Kotaro; Sugiyama, Koichiro; Yonekura, Yosinori; Fujisawa, Kenta

    2015-01-01

    We report on a long-term single-dish and VLBI monitoring for intermittent flare activities of a Dominant Blue-Shifted H$_{2}$O Maser (DBSM) associated with a southern high mass young stellar object, G353.273+0.641. Bi-weekly single-dish monitoring using Hokkaido University Tomakomai 11-m radio telescope has shown that a systematic acceleration continues over four years beyond a lifetime of individual maser features. This fact suggests that the H$_{2}$O maser traces a region where molecular gas is steadily accelerated. There were five maser flares during five-years monitoring, and maser distributions in four of them were densely monitored by the VLBI Exploration of Radio Astrometry (VERA). The overall distribution of the maser features suggests the presence of a bipolar jet, with the 3D kinematics indicating that it is almost face-on (inclination angle of $\\sim$ 8$^{\\fdg}$--17$^{\\fdg}$ from the line-of-sight). Most of maser features were recurrently excited within a region of 100$\\times$100 AU$^{2}$ around the...

  20. Analysis of ex-vessel melt jet breakup and coolability. Part 1: Sensitivity on model parameters and accident conditions

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, Kiyofumi; Park, Hyun Sun, E-mail: hejsunny@postech.ac.kr; Hwang, Byoungcheol; Jung, Woo Hyun

    2016-06-15

    Highlights: • Application of JASMINE code to melt jet breakup and coolability in APR1400 condition. • Coolability indexes for quasi steady state breakup and cooling process. • Typical case in complete breakup/solidification, film boiling quench not reached. • Significant impact of water depth and melt jet size; weak impact of model parameters. - Abstract: The breakup of a melt jet falling in a water pool and the coolability of the melt particles produced by such jet breakup are important phenomena in terms of the mitigation of severe accident consequences in light water reactors, because the molten and relocated core material is the primary heat source that governs the accident progression. We applied a modified version of the fuel–coolant interaction simulation code, JASMINE, developed at Japan Atomic Energy Agency (JAEA) to a plant scale simulation of melt jet breakup and cooling assuming an ex-vessel condition in the APR1400, a Korean advanced pressurized water reactor. Also, we examined the sensitivity on seven model parameters and five initial/boundary condition variables. The results showed that the melt cooling performance of a 6 m deep water pool in the reactor cavity is enough for removing the initial melt enthalpy for solidification, for a melt jet of 0.2 m initial diameter. The impacts of the model parameters were relatively weak and that of some of the initial/boundary condition variables, namely the water depth and melt jet diameter, were very strong. The present model indicated that a significant fraction of the melt jet is not broken up and forms a continuous melt pool on the containment floor in cases with a large melt jet diameter, 0.5 m, or a shallow water pool depth, ≤3 m.

  1. Core 2D. A code for non-isothermal water flow and reactive solute transport. Users manual version 2

    Energy Technology Data Exchange (ETDEWEB)

    Samper, J.; Juncosa, R.; Delgado, J.; Montenegro, L. [Universidad de A Coruna (Spain)

    2000-07-01

    Understanding natural groundwater quality patterns, quantifying groundwater pollution and assessing the effects of waste disposal, require modeling tools accounting for water flow, and transport of heat and dissolved species as well as their complex interactions with solid and gases phases. This report contains the users manual of CORE ''2D Version V.2.0, a COde for modeling water flow (saturated and unsaturated), heat transport and multicomponent Reactive solute transport under both local chemical equilibrium and kinetic conditions. it is an updated and improved version of CORE-LE-2D V0 (Samper et al., 1988) which in turns is an extended version of TRANQUI, a previous reactive transport code (ENRESA, 1995). All these codes were developed within the context of Research Projects funded by ENRESA and the European Commission. (Author)

  2. The use of water-jetting technology in prostheses revision surgery-first results of parameter studies on bone and bone cement.

    Science.gov (United States)

    Honl, M; Rentzsch, R; Müller, G; Brandt, C; Bluhm, A; Hille, E; Louis, H; Morlock, M

    2000-01-01

    Water-jet cutting techniques have been used in industrial applications for many different materials. Recently these techniques have been developed into a revolutionary cutting tool for soft tissues in visceral surgery. The present study investigates the usage of this cutting technology for the revision surgery of endoprostheses. In the first part of the study, samples of bovine bone and acrylic bone cement (PMMA) were cut using an industrial jet cutting device with pure water. Below 400 bar, only PMMA was cut; above 400 bar, bone was also cut, but only pressures above 800 bar resulted in clinically useful rates of material removal (cut depth 2. 4 mm at 10 mm/min traverse speed). In the second part of the study, the effect of adding biocompatible abrasives to the water in order to reduce the required pressure was investigated, resulting in a significantly higher removal of material. At 600 bar, PMMA was cut 5. 2 mm deep with plain water and 15.2 mm deep with added abrasives. The quality of the cuts was increased by the abrasive. Though there was no clear selectivity between bone and PMMA any more, the rate of material removal at similar pressures was significantly higher for PMMA than for bone (600 bar: 1.6 mm cut depth for bone samples, 15.2 mm for PMMA). The measured cut depths with either method were not influenced by a change of the cutting direction with respect to the main direction of the osteons in the bone. However, a reduction of the jet surface angle (90 degrees to 23 degrees ) resulted for bone in a significantly lower cut depth at 600 bar (plain water: 0.62 mm vs. 0.06 mm; abrasive: 1.61 mm vs. 0.60 mm). The laboratory experiments indicate that abrasive water jets may be suitable for cutting biomaterials like bone and bone cement.

  3. Verification of Dinamika-5 code on experimental data of water level behaviour in PGV-440 under dynamic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Beljaev, Y.V.; Zaitsev, S.I.; Tarankov, G.A. [OKB Gidropress (Russian Federation)

    1995-12-31

    Comparison of the results of calculational analysis with experimental data on water level behaviour in horizontal steam generator (PGV-440) under the conditions with cessation of feedwater supply is presented in the report. Calculational analysis is performed using DIMANIKA-5 code, experimental data are obtained at Kola NPP-4. (orig.). 2 refs.

  4. Experimental and analytical studies of melt jet-coolant interactions: a synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, T.N.; Bui, V.A.; Nourgaliev, R.R.; Green, J.A.; Sehgal, B.R. [Royal Inst. of Tech., Stockholm (Sweden). Div. of Nuclear Power Safety

    1998-01-01

    Instability and fragmentation of a core melt jet in water have been actively studied during the past ten years. Several models, and a few computer codes, have been developed. However, there are, still, large uncertainties, both, in interpreting experimental results and in predicting reactor-scale processes. Steam explosion and debris coolability, as reactor safety issues, are related to the jet fragmentation process. A better understanding of the physics of jet instability and fragmentation is crucial for assessments of fuel-coolant interactions (FCIs). This paper presents research, conducted at the Division of Nuclear Power Safety, Royal Institute of Technology (RIT/NPS), Stockholm, concerning molten jet-coolant interactions, as a precursor for premixing. First, observations were obtained from scoping experiments with simulant fluids. Second, the linear perturbation method was extended and applied to analyze the interfacial-instability characteristics. Third, two innovative approachs to CFD modeling of jet fragmentation were developed and employed for analysis. The focus of the studies was placed on (a) identifying potential factors, which may affect the jet instability, (b) determining the scaling laws, and (c) predicting the jet behavior for severe accidents conditions. In particular, the effects of melt physical properties, and the thermal hydraulics of the mixing zone, on jet fragmentation were investigated. Finally, with the insights gained from a synthesis of the experimental results and analysis results, a new phenomenological concept, named `macrointeractions concept of jet fragmentation` is proposed. (author)

  5. Fuzzy jets

    Energy Technology Data Exchange (ETDEWEB)

    Mackey, Lester [Department of Statistics, Stanford University,Stanford, CA 94305 (United States); Nachman, Benjamin [Department of Physics, Stanford University,Stanford, CA 94305 (United States); SLAC National Accelerator Laboratory, Stanford University,2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Schwartzman, Ariel [SLAC National Accelerator Laboratory, Stanford University,2575 Sand Hill Rd, Menlo Park, CA 94025 (United States); Stansbury, Conrad [Department of Physics, Stanford University,Stanford, CA 94305 (United States)

    2016-06-01

    Collimated streams of particles produced in high energy physics experiments are organized using clustering algorithms to form jets. To construct jets, the experimental collaborations based at the Large Hadron Collider (LHC) primarily use agglomerative hierarchical clustering schemes known as sequential recombination. We propose a new class of algorithms for clustering jets that use infrared and collinear safe mixture models. These new algorithms, known as fuzzy jets, are clustered using maximum likelihood techniques and can dynamically determine various properties of jets like their size. We show that the fuzzy jet size adds additional information to conventional jet tagging variables in boosted topologies. Furthermore, we study the impact of pileup and show that with some slight modifications to the algorithm, fuzzy jets can be stable up to high pileup interaction multiplicities.

  6. Experimental investigation of 150-KG-scale corium melt jet quenching in water

    Energy Technology Data Exchange (ETDEWEB)

    Magallon, D.; Hohmann, H.

    1995-09-01

    This paper compares and discusses the results of two large scale FARO quenching tests known as L-11 and L-14, which involved, respectively, 151 kg of W% 76.7 UO{sub 2} + 19.2 ZrO{sub 2} + 4.1 Zr and 125 kg of W% 80 UO{sub 2} + 20 ZrO{sub 2} melts poured into 600-kg, 2-m-depth water at saturation at 5.0 MPa. The results are further compared with those of two previous tests performed using a pure oxidic melt, respectively 18 and 44 kg of W% 80 UO{sub 2} + 20 ZrO{sub 2} melt quenched in 1-m-depth water at saturation at 5.0 MPa. In all the tests, significant breakup and quenching took place during the melt fall through the water. No steam explosion occurred. In the tests performed with a pure oxide UO{sub 2}-ZrO{sub 2} melt, part of the corium (from 1/6 to 1/3) did not breakup and reached the bottom plate still molten whatever the water depth was. Test L-11 data suggest that full oxidation and complete breakup of the melt occurred during the melt fall through the water. A proportion of 64% of the total energy content of the melt was released to the water during this phase ({approximately}1.5 s), against 44% for L-14. The maximum temperature increase of the bottom plate was 330 K (L-14). The mean particle size of the debris ranged between 2.5 and 4.8mm.

  7. Determination of the δ15N of nitrate in water; RSIL lab code 2899

    Science.gov (United States)

    Coplen, Tyler B.; Qi, Haiping; Revesz, Kinga; Casciotti, Karen; Hannon, Janet E.

    2007-01-01

    The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 2899 is to determine the δ15N of nitrate (NO3-) in water. The δ15N of the dissolved NO3- is analyzed by conversion of the NO3- to nitrous oxide (N2O), which serves as the analyte for mass spectrometry. A culture of denitrifying bacteria is used in the enzymatic conversion of the NO3- to N2O, which follows the pathway shown in equation 1: NO3- → NO2- → NO → 1/2 N2O (1) Because the bacteria Pseudomonas aureofaciens lack N2O reductive activity, the reaction stops at N2O, unlike the typical denitrification reaction that goes to N2. After several hours, the conversion is complete, and the N2O is extracted from the vial, separated from volatile organic vapor and water vapor by an automated -65 °C isopropanol-slush trap, a Nafion drier, a CO2 and water removal unit (Costech #021020 carbon dioxide absorbent with Mg(ClO4)2), and trapped in a small-volume trap immersed in liquid nitrogen with a modified Finnigan MAT (now Thermo Scientific) GasBench 2 introduction system. After the N2O is released, it is further purified by gas chromatography before introduction to the isotope-ratio mass spectrometer (IRMS). The IRMS is a Thermo Scientific Delta V Plus continuous flow IRMS (CF-IRMS). It has a universal triple collector, consisting of two wide cups with a narrow cup in the middle; it is capable of simultaneously measuring mass/charge (m/z) of the N2O molecule 44, 45, and 46. The ion beams from these m/z values are as follows: m/z = 44 = N2O = 14N14N16O; m/z = 45 = N2O = 14N15N16O or 14N14N17O; m/z = 46 = N2O = 14N14N18O. The 17O contributions to the m/z 44 and m/z 45 ion beams are accounted for before δ15N values are reported.

  8. Interacting Jets from Binary Protostars

    CERN Document Server

    Murphy, G C; O'Sullivan, S; Spicer, D; Bacciotti, F; Rosén, A

    2007-01-01

    We investigate potential models that could explain why multiple proto-stellar systems predominantly show single jets. During their formation, stars most frequently produce energetic outflows and jets. However, binary jets have only been observed in a very small number of systems. We model numerically 3D binary jets for various outflow parameters. We also model the propagation of jets from a specific source, namely L1551 IRS 5, known to have two jets, using recent observations as constraints for simulations with a new MHD code. We examine their morphology and dynamics, and produce synthetic emission maps. We find that the two jets interfere up to the stage where one of them is almost destroyed or engulfed into the second one. We are able to reproduce some of the observational features of L1551 such as the bending of the secondary jet. While the effects of orbital motion are negligible over the jets dynamical timeline, their interaction has significant impact on their morphology. If the jets are not strictly pa...

  9. A new thermal hydraulics code coupled to agent for light water reactor analysis

    Science.gov (United States)

    Eklund, Matthew Deric

    A new numerical model for coupling a thermal hydraulics method based on the Drift Flux and Homogeneous Equilibrium Mixture (HEM) models, with a deterministic neutronics code system AGENT (Arbitrary Geometry Neutron Transport), is developed. Named the TH thermal hydraulics code, it is based on the mass continuity, momentum, and energy equations integrated with appropriate relations for liquid and vapor phasic velocities. The modified conservation equations are then evaluated in one-dimensional (1D) steady-state conditions for LWR coolant subchannel in the axial direction. This permits faster computation times without sacrificing significant accuracy, as compared to other three-dimensional (3D) codes such as RELAP5/TRACE. AGENT is a deterministic neutronics code system based on the Method of Characteristics to solve the 2D/3D neutron transport equation in current and future reactor systems. The coupling scheme between the TH and AGENT codes is accomplished by computing the normalized fission rate profile in the LWR fuel elements by AGENT. The normalized fission rate profile is then transferred to the TH thermal hydraulics code for computing the reactor coolant properties. In conjunction with the 1D axial TH code, a separate 1D radial heat transfer model within the TH code is used to determine the average fuel temperature at each node where coolant properties are calculated. These properties then are entered into Scale 6.1, a criticality analysis code, to recalculate fuel pin neutron interaction cross sections based on thermal feedback. With updated fuel neutron interaction cross sections, the fission rate profile is recalculated in AGENT, and the cycle continues until convergence is reached. The TH code and coupled AGENT-TH code are benchmarked against the TRACE reactor analysis software, showing required agreement in evaluating the basic reactor parameters.

  10. Isolation and differentiation potential of human mesenchymal stem cells from adipose tissue harvested by water jet-assisted liposuction.

    Science.gov (United States)

    Meyer, Juliane; Salamon, Achim; Herzmann, Nicole; Adam, Stefanie; Kleine, Hans-Dieter; Matthiesen, Inge; Ueberreiter, Klaus; Peters, Kirsten

    2015-11-01

    In recent years the therapeutic application of extracted adipose tissue for autologous fat grafting and the application of adipose tissue-derived mesenchymal stem cells (adMSC) isolated thereof has progressed. Water-jet assisted liposuction (WAL) is 1 procedure for harvesting adipose tissue and provides a favorable aesthetic outcome combined with high tissue protection. Tissue aspirated by WAL has been successfully applied in grafting procedures. The aims of this study were to confirm the tissue viability and to understand the abundance and mesenchymal differentiation capacity of stem cells within the tissue. We analyzed tissue integrity of WAL tissue particles via fluorescence microscopy. The adMSC content was determined by isolating the cells from the tissue. The mesenchymal differentiation capacity was confirmed with cytochemical staining methods. The stromal vascular fraction of WAL tissue showed high viability and contained an average of 2.6 × 105 CD34-positive cells per milliliter of tissue. Thus WAL tissue contains a high number of stem cells. Furthermore adMSC isolated from WAL tissue showed typical mesenchymal differentiation potential. WAL of adipose tissue is well suited for autologous fat grafting because it retains tissue viability. Furthermore it is a valid source for the subsequent isolation of adMSC with multipotent differentiation potential. 3 Therapeutic. © 2015 The American Society for Aesthetic Plastic Surgery, Inc. Reprints and permission: journals.permissions@oup.com.

  11. 3D Modelling of a Vectored Water Jet-Based Multi-Propeller Propulsion System for a Spherical Underwater Robot

    Directory of Open Access Journals (Sweden)

    Xichuan Lin

    2013-01-01

    Full Text Available This paper presents an improved modelling method for a water jet-based multi-propeller propulsion system. In our previous work, the modelling experiments were only carried out in 2D planes, whose experimental results had poor agreement when we wanted to control the propulsive forces in 3D space directly. This research extends the 2D modelling described in the authors' previous work into 3D space. By doing this, the model could include 3D space information, which is more useful than that of 2D space. The effective propulsive forces and moments in 3D space can be obtained directly by synthesizing the propulsive vectors of propellers. For this purpose, a novel experimental mechanism was developed to achieve the proposed 3D modelling. This mechanism was designed with the mass distribution centred for the robot. By installing a six-axis load-cell sensor at the equivalent mass centre, we obtained the direct propulsive effect of the system for the robot. Also, in this paper, the orientation surface and propulsive surfaces are developed to provide the 3D information of the propulsive system. Experiments for each propeller were first carried out to establish the models. Then, further experiments were carried out with all of the propellers working together to validate the models. Finally, we compared the various experimental results with the simulation data. The utility of this modelling method is discussed at length.

  12. Enhanced photocatalytic-electrolytic degradation of Reactive Brilliant Red X-3B in the presence of water jet cavitation.

    Science.gov (United States)

    Wang, Xiaoning; Jia, Jinping; Wang, Yalin

    2015-03-01

    Photocatalysis, electrolysis, water jet cavitation (WJC), alone and in combinations were applied to degrade an azo dye, Reactive Brilliant Red X-3B (X-3B). Experiments were conducted in a 4.0 L aqueous solution with different initial dye concentrations, TiO₂ dose, and solution pH. WJC substantially increased the photocatalytic, electrolytic and photocatalytic-electrolytic rates of the dye removal. The observed first-order rate of X-3B decolorization in the process of combined photocatalysis and electrolysis coupled with WJC was 1.6-2.9 times of that in the process of combined photocatalysis and electrolysis coupled with mechanical stirring. The rate enhancements may be attributed primarily to the reduced diffusion layer thickness on the electrodes and the deagglomeration of photocatalyst particles due to the chemical and physical effects of WJC. Under the conditions of 80 mg/L X-3B solution, 100 mg/L TiO₂ dose and solution pH 6.3, 97% and 71% of color and chemical oxygen demand (CODCr) were removed, respectively, within 90-min photocatalytic-electrolytic treatment coupled with WJC. During this process, azo groups and naphthalene, benzene and triazine structures of the dye can be destroyed. Industrial textile effluent was also investigated, and a positive synergistic effect between photocatalytic-electrolytic system and WJC was observed considering color removal. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Introduction to Climbing Wall Robot for High Pressure Water Jet Cutting%基于高压水射流技术的爬壁机器人介绍

    Institute of Scientific and Technical Information of China (English)

    罗晓凯; 龚烈航; 孙义柯

    2016-01-01

    介绍了几种常见的且已投入实际生产工作的爬壁机器人的结构原理,同时分析了在结合高压水射流切割技术后,各类机器人的性能优势以及不足之处。最后论述了在日益发展迅速的高压水射流切割技术下,爬壁机器人在技术方面所面临的一些问题。%This paper introduced the working principle of several kinds of climbing robots used in practical production ,analyzed their advantages and disadvantages after combining with high-pressure water jet cutting technology .At last ,the paper discussed some problems in climbing wall robots ,with the rapid development of high-pressure water jet cutting technology .

  14. Jet Observables Without Jet Algorithms

    CERN Document Server

    Bertolini, Daniele; Thaler, Jesse

    2013-01-01

    We introduce a new class of event shapes to characterize the jet-like structure of an event. Like traditional event shapes, our observables are infrared/collinear safe and involve a sum over all hadrons in an event, but like a jet clustering algorithm, they incorporate a jet radius parameter and a transverse momentum cut. Three of the ubiquitous jet-based observables---jet multiplicity, summed scalar transverse momentum, and missing transverse momentum---have event shape counterparts that are closely correlated with their jet-based cousins. Due to their "local" computational structure, these jet-like event shapes could potentially be used for trigger-level event selection at the LHC. Intriguingly, the jet multiplicity event shape typically takes on non-integer values, highlighting the inherent ambiguity in defining jets. By inverting jet multiplicity, we show how to characterize the transverse momentum of the n-th hardest jet without actually finding the constituents of that jet. Since many physics applicatio...

  15. Design on Shells Water Jet Cutting Device Mechanical Structure%炮弹水刀切割装置结构设计

    Institute of Scientific and Technical Information of China (English)

    李鑫勇; 王彪; 杨福合; 郝少楠

    2011-01-01

    It's a very dangerous work of disposal, storage and transportation of scrap shells, because that's easy to cause accidents which will bring about casualties and property losses owing to any carelessness. While the using of water jet cutting device to dispose scrap shells is a safe, reliable and non-pollution method. A water jet cutting device was designed and high-tech of ultrahigh-pres-sure water jet " cold-cutting" was adopted to open the shell body and high pressure water jet was used to make explosives and shell body isolate. Scrap shell was destroyed and useful metal was recovered. Hydraulic three-jaw chuck was used to realize automatic positioning and clamping of shell. The rotating cutting method can improve the life of the whole hydraulic drive system.%报废炮弹的处理销毁及贮运工作是非常危险的,稍有不慎,极易发生事故,造成人员伤亡与财产损失。采用水刀切割装置处理报废炮弹,安全可靠且不污染环境。设计水刀切割装置,采用超高压水射流“冷态切割”技术将弹体切开,并利用高压水射流冲洗使炸药和弹体分离,销毁炮弹并回收有用金属。采用液动三爪卡盘实现炮弹的自动定位与夹紧,利用旋转切割的方法切割炮弹,提高了整个水刀系统的寿命。

  16. INVESTIGATION SURFACE ROUGHNESS AND CHARACTERIZATION OF CUTTING FRONT SIDE GEOMETRY IN THE CUTTING OF AISI 1030 MATERIAL WITH ABRASIVE WATER JET

    Directory of Open Access Journals (Sweden)

    Adnan AKKURT

    2009-01-01

    Full Text Available Abrasive water jet (AWJ is used as a new and alternative cutting technique in industry to form the materials that are hard to cut. In this study, AISI 1030 steel samples in different thickness were cut with AWJ process. The samples were cut with different cutting speeds. The effect of cutting speed on the surface characteristics was investigated. The results of the study show that AWJ can be used as an effective cutting process to form sharp corners and edges.

  17. 钢粒子水射流联合破岩试验研究%Experimental Study on Combined Breaking Rock with Steel Particles and Water Jet

    Institute of Scientific and Technical Information of China (English)

    司垒; 胡正伟; 许瑞

    2012-01-01

    在自制的截割试验台进行钢粒子水射流联合破岩的试验研究,对截齿破岩冲蚀体积测量,通过截割测试系统对截齿截割力实时监测.试验结果表明:在同一条件下,钢粒子水射流联合破岩效果明显优于纯水射流辅助破岩;钢粒子水射流联合破岩的实际最优粒径为0.5 ~ 1.5mm;钢粒子水射流联合截割时截割力的平均值、最大一平均值以及最大值都比纯水射流辅助截割时要小得多,且所受截割力的波动性也很小.%The experimental study on combined breaking rock with steel particles and water jet was carried on the selfmade cutting laboratory bench. The pick rock - volume was measured and the cutting force of the picks was real - lime monitored through the cutting test system. Results shows that; under the same conditions, the rock -breaking effect of steel particles and water jet is significantly better than water jet assistant cutting, and the optimal parameters of particle diameter is 0.5 ~ 1.5 mm. The average , maximum - average , maximum and the volatility of the cutting force is also much smaller when combined breaking rock with steel particles and water jet.

  18. Study on similar model of high pressure water jet impacting coal rock

    Science.gov (United States)

    Liu, Jialiang; Wang, Mengjin; Zhang, Di

    2017-08-01

    Based on the similarity theory and dimensional analysis, the similarity criterion of the coal rock mechanical parameters were deduced. The similar materials were mainly built by the cement, sand, nitrile rubber powder and polystyrene, by controlling the water-cement ratio, cement-sand ratio, curing time and additives volume ratio. The intervals of the factors were obtained by carrying out series of material compression tests. By comparing the basic mechanical parameters such as the bulk density, compressive strength, Poisson ratio and elastic modulus between the coal rock prototype and similar materials, the optimal producing proposal of the coal rock similar materials was generated based on the orthogonal design tests finally.

  19. Pulsed laser ablation of wire-shaped target in a thin water jet: effects of plasma features and bubble dynamics on the PLAL process

    Science.gov (United States)

    Dell'Aglio, Marcella; De Giacomo, Alessandro; Kohsakowski, Sebastian; Barcikowski, Stephan; Wagener, Philipp; Santagata, Antonio

    2017-05-01

    In this paper, emission spectroscopy and fast imaging surveys during pulsed laser ablation in liquid (PLAL) for nanoparticles (NPs) production have been used, in order to provide further details about the process involved and the potentialities offered by a wire-shaped sample ablated in a flowing water jet. This kind of set-up has been explored because the laser ablation efficiency in water increases when a thin water layer and a wire-shaped target are used. In order to understand the physical processes causing the increasing ablation efficiency, both the laser-induced plasma and bubble dynamics generated in a flowing liquid jet have been analysed. The plasma parameters and the bubble behaviour in such a system have been compared with those observed in conventional PLAL experiments, where either a bulk or a wire-shaped target is immersed in bulk water. From the data presented here it is evidenced that the plasma and shockwave induced during the breakdown process can play a direct role in the ablation efficiency variation observed. With regard to the cavitation bubbles evolving near a free surface (the interface between water and air) it should be noted that these have to be treated with caution as a consequence of the strong influence played in these circumstances by the boundary of the water jet during its expansion dynamics. The effects due to the size of the liquid layer, the presence of the water/air interface, the liquid characteristics, the target shape, the plasma evolution and the bubble dynamics together with their outcomes on the NPs’ production, are presented and discussed.

  20. The research and manufacture of numerical control abrasive water-jet machine tool%磨料水射流数控机床的研究与开发

    Institute of Scientific and Technical Information of China (English)

    贾明峰; 俞涛; 方明伦; 林金生

    2001-01-01

    This paper introduces application and foreground of abrasive water jet, and introduces general structure and working principle of CNC abrasive water-jet machine tool.%介绍了磨料水射流技术广泛的应用及前景,并详细地介绍了磨料水射流数控切割机床的总体结构、工作原理和机构设计。

  1. 水切割机器人路径规划方法%Path planning method of water-jet cutting robot

    Institute of Scientific and Technical Information of China (English)

    王玫; 孟正大

    2012-01-01

    以汽车内饰件切割路径优化为研究对象,提出了一种改进禁忌表蚁群算法,实现优化排序.根据水切割过程特点和工艺要求,进行了水切割路径规划问题分析与建模,设计了改进的禁忌表,利用分层思想将禁忌表划分为3段:内部小环段、内部大环段和外部轮廓段,各段的优先级依次降低,并确定了与此相应的禁忌表的更新规则.在此基础上,给出了基于改进禁忌表蚁群算法的水切割路径优化排序方法,对轮廓切割顺序和各轮廓起始点选择同时进行优化.仿真与实验结果表明,改进禁忌表蚁群算法是可行、有效的,可大大缩短水切割机器人的示教编程时间,显著提高水切割作业的效率和质量.%Taking the optimization of path planning of cutting automotive interior ornament as the research object, an improved tabu list based ant colony algorithm is presented to achieve cutting sequence optimization. According to the characteristics and technology demands of the water-jet cutting process, water-jet cutting path planning problem was analyzed and modeled. Taking advantage of the hierarchy principle, an improved tabu list was designed, which was divided into three sections : interior small loop, interior large loop, exterior outline section, and their priority reduces successively. Corresponding updating rules of the tabu list were proposed. The water-jet cutting path planning method based on the improved ant colony algorithm was proposed with which the cutting sequence of outlines and selection of starting point for cutting every outline are optimized simultaneously. Simulation and experimental results show that the improved tabu list based ant colony algorithm is feasible and effective. The teaching programming time of water-jet cutting robots can be shorten greatly, efficiency and quality of water-jet cutting jobs can be raised evidently.

  2. Generalized fragmentation functions for fractal jet observables

    Science.gov (United States)

    Elder, Benjamin T.; Procura, Massimiliano; Thaler, Jesse; Waalewijn, Wouter J.; Zhou, Kevin

    2017-06-01

    We introduce a broad class of fractal jet observables that recursively probe the collective properties of hadrons produced in jet fragmentation. To describe these collinear-unsafe observables, we generalize the formalism of fragmentation functions, which are important objects in QCD for calculating cross sections involving identified final-state hadrons. Fragmentation functions are fundamentally nonperturbative, but have a calculable renormalization group evolution. Unlike ordinary fragmentation functions, generalized fragmentation functions exhibit nonlinear evolution, since fractal observables involve correlated subsets of hadrons within a jet. Some special cases of generalized fragmentation functions are reviewed, including jet charge and track functions. We then consider fractal jet observables that are based on hierarchical clustering trees, where the nonlinear evolution equations also exhibit tree-like structure at leading order. We develop a numeric code for performing this evolution and study its phenomenological implications. As an application, we present examples of fractal jet observables that are useful in discriminating quark jets from gluon jets.

  3. Demulsification Experimental on Emulsified Oil Wastewater by Cavitation Water Jet%乳化油废水空化射流破乳实验

    Institute of Scientific and Technical Information of China (English)

    管金发; 邓松圣; 陈明; 伍建林

    2016-01-01

    建立了空化射流破乳实验系统,确定了空化射流破乳实验方法。以空化射流破乳除油率作为衡量空化射流破乳效果好坏的标准,通过实验研究了表面活性剂质量浓度、油的质量浓度、静置时间、喷嘴入口压力、循环处理次数、靶距对空化射流破乳效果的影响规律。结果表明:与未添加表面活性剂相比,添加少量表面活性剂将使空化射流破乳除油率大幅度下降;空化射流破乳方法主要对不含表面活性剂的模型乳化油废水有一定效果;空化射流破乳除油率随着模型乳化油废水油的质量浓度、静置时间、喷嘴入口压力的增加而增加;循环处理次数较少时,空化射流破乳除油率随着循环处理次数的增加而增加,但循环处理次数过多反而使除油率下降;存在最佳靶距280 mm。%Cavitation water jet demulsification experiment system was established, and the method of cavitation water jet de⁃mulsification experiment was confirmed. Taking the oil removal rate of cavitation water jet demulsification as the criterion of the de⁃mulsification effect of cavitation water jet, influences of the surfactant mass concentration, oil mass concentration, standing time, nozzle inlet pressure, circulation treatment times and standoff distance on demulsification effect of cavitation water jet were studied experimentally. Results show that compared to the case that surfactant mass concentration is zero, with a little surfactant added to it, the oil removal rate decrease greatly. Namely the demulsification method of cavitation water jet mainly has a demulsification effect for emulsified oil wastewater that surfactant mass concentration is zero. The oil removal rate of cavitation water jet demulsification increases with the increase of oil mass concentration of emulsified oil wastewater, standing time and nozzle inlet pressure. When the times of circulation treatment is small, oil

  4. The Piezo Actuator-Driven Pulsed Water Jet System for Minimizing Renal Damage after Off-Clamp Laparoscopic Partial Nephrectomy.

    Science.gov (United States)

    Kamiyama, Yoshihiro; Yamashita, Shinichi; Nakagawa, Atsuhiro; Fujii, Shinji; Mitsuzuka, Koji; Kaiho, Yasuhiro; Ito, Akihiro; Abe, Takaaki; Tominaga, Teiji; Arai, Yoichi

    2017-01-01

    In the setting of partial nephrectomy (PN) for renal cell carcinoma, postoperative renal dysfunction might be caused by surgical procedure. The aim of this study was to clarify the technical safety and renal damage after off-clamp laparoscopic PN (LPN) with a piezo actuator-driven pulsed water jet (ADPJ) system. Eight swine underwent off-clamp LPN with this surgical device, while off-clamp open PN was also performed with radio knife or soft coagulation. The length of the removed kidney was 40 mm, and the renal parenchyma was dissected until the renal calyx became clearly visible. The degree of renal degeneration from the resection surface was compared by Hematoxylin-Eosin staining and immunostaining for 1-methyladenosine, a sensitive marker for the ischemic tissue damage. The mRNA levels of neutrophil gelatinase-associated lipocalin (Ngal), a biomarker for acute kidney injury, were measured by quantitative real-time PCR. Off-clamp LPN with ADPJ system was successfully performed while preserving fine blood vessels and the renal calix with little bleeding. In contrast to other devices, the resection surface obtained with the ADPJ system showed only marginal degree of ischemic changes. Indeed, the expression level of Ngal mRNA was lower in the resection surface obtained with the ADPJ system than that with soft coagulation (p = 0.02). Furthermore, using the excised specimens of renal cell carcinoma, we measured the breaking strength at each site of the human kidney, suggesting the applicability of this ADPJ to clinical trials. In conclusion, off-clamp LPN with the ADPJ system could be safely performed with attenuated renal damage.

  5. Quantitative evaluation of the oral biofilm-removing capacity of a dental water jet using an electron-probe microanalyzer.

    Science.gov (United States)

    Kato, Kazuo; Tamura, Kiyomi; Nakagaki, Haruo

    2012-01-01

    This study was conducted to evaluate the oral biofilm-removing capacity of a dental water jet (DWJ) by measuring biofilm thickness using an electron-probe microanalyzer (EPMA). Thirty consenting subjects wore in situ plaque-generating devices, which consisted of a pair of 4mm(2) enamel slabs attached to the upper molars for 2 days. Each device removed from the mouth was clamped, and one of the slab surfaces was treated with the DWJ, irrigating it for 5s. The devices were randomly assigned to three different pressure settings of 707, 350 or 102kPa. Another slab with no treatment served as a control. Each slab was freeze-dried, sputter-coated with platinum, and examined using secondary-electron imaging. The slabs were then embedded in methacrylate and cross-sectioned in the centre. Their surfaces were polished, coated with carbon, and examined using backscattered electron compositional (COMPO) imaging. The area between the enamel and the outer biofilm surface, indicated by a thin platinum layer, was measured by COMPO imaging to calculate the average thickness of the biofilm on the specimen. The removal capacity of biofilm by irrigation was estimated using a reduced rate of biofilm thickness, which was calculated from the differences between a pair of treated and control slabs. The reduced rates were 85.5% at 707kPa, 85.1% at 350kPa and 63.4% at 102kPa, indicating that biofilm thickness was significantly reduced at every pressure setting. The results suggest that irrigation using a DWJ would be an effective means of plaque control. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. The role of water-jet dissection in improving erectile function and urinary continence after nerve-sparing prostatectomy.

    Science.gov (United States)

    Glybochko, Peter V; Rapoport, Leonid M; Bezrukov, Eugene A; Sirota, Eugene S; Martirosyan, Gurgen A

    2017-08-01

    The aim of this study was to assess erectile function (EF) and urinary continence (UC) recovery after nerve-sparing retropubic radical prostatectomy (NS-RRPE) and nerve-sparing laparoscopic radical prostatectomy (NS-LRPE) depending on the neurovascular bundle (NVB) dissection technique used. Twenty-four hour pad test was used to assess the degree of postoperative UC 1, 6 and 12 months after the surgery. For the purpose of EF assessment, International Index of Erectile Function-5 (IIEF-5) questionnaire was used. In addition, EF recovery assessment included the time needed to achieve a successful sexual intercourse with or without Inhibitors Phosphodiesterase 5 (IPDE5). A successful sexual intercourse was defined as an ability to achieve a strong erection enough for penetration and maintain erection for a long time, throughout the intercourse. Assessment was performed before the surgery and 8 and 6 months after the surgery. In the patient group with BNS + water jet dissection (WJD), the IIEF-5 score was considerably higher 8 weeks after the surgery (by 2.8 points) (р = 0.02). In 6 months, the difference between the group become more significant and reached 3.5 points (p = 0.01). Three months after urethral catheter removal, majority (95%) of patients in the NS-RPE + WJD group had no urinary incontinence (UI). For standard NS-RPE, that figure was 87%. Mild stress UI was observed in 5% of patients after NS-RPE + WJD and in 13% of patients after NS-RPE. Six months after urethral catheter removal, no significant differences in UC assessment were observed in the two groups. The implementation of WJD of NVB in clinical practice has made it possible to considerably improve the quality of life for postoperative patients due to good outcomes in terms of early UC and EF recovery.

  7. Calibration in a potential water jet of a five-hole pressure probe with embedded sensors for unsteady flow measurement

    Science.gov (United States)

    Duquesne, P.; Desch"nes, C.; Iliescu, M.; Ciocan, G. D.

    2010-03-01

    Investigations of the flow behavior are currently carried out experimentally on models of hydraulic turbines. Quantities such as unsteady velocity can be acquired using PIV or LDV techniques, static wall pressure using steady or unsteady pressure transducers and wall shear stress using hot-film anemometry. More rarely acquired however, the unsteady total pressure at different locations in the flowstream would give more information on the flow dynamics and would be a key component for setting boundary conditions for CFD simulations. Following the example of classical Pitot tubes, which can only give averaged pressure values though, we have developed a five-hole pressure probe with embedded sensors that can measure unsteady values of total pressure, local flow velocity and direction. The probe head is designed to have a minimum impact on the flowstream, and the miniature sensors are placed in a cross configuration compared to the probe's support axis. This paper focuses on the utilization of normalized calibration coefficients and their use for unsteady values, and on the justification for using our cross sensor repartition. The calibration setup is presented briefly, including a water potential jet that requires the calculation of specific calibration coefficients. Different phenomena were observed during experimentation. Their impact on the accuracy of the probe is analyzed. The probe's operation range for this particular calibration setup is discussed. Finally, we focus on the influence of the sensors repartition on the tridimensional shape of the calibration coefficients, and we provide a way to calculate the first approximate solution for the reverse calculus while the sensors are not aligned with the probe's arm.

  8. 水射流切割黏弹性药柱的仿真研究%Numerical Simulation of Water Jet Cutting Viscoelastic Propellant

    Institute of Scientific and Technical Information of China (English)

    周超英; 文立华

    2011-01-01

    According to the water jet cutting operation requiring high safety,the issue is studied that how to remove the solid rocket motor propellant safely and effectively. To improve and optimize the jet device parameters impacting cutting efficacy and safety,five different simulations are proposed basing on ls-dyna software. Through the analysis, the water jet cutting propellant mechanism and the reasonable cutting process parameters are attained, the results show that the bigger of spout diameter, the bigger cutting depth is but the change of surface pressure is not obvious; the bigger of jet velocity, the bigger cutting depth is and the pressure on the surface of the propellant is bigger also. Take inclined cut way is preferred. The simulation scheme validity and practicability are proved.%针对要求安全性高的水射流切割药柱操作,研究了如何安全有效的切割清除固体火箭发动机药柱问题.为改善和优化影响切割效果和安全性的射流器工艺参数,提出了基于LS-DYNA软件对五种不同条件下水柱冲击药柱的仿真方案.通过分析,得出水射流切割药柱的机理和合理的切割工艺参数.结果表明,喷口直径越大,导致切割深度越大但对药柱表面压强影响不明显.射流速度越大,导致切割深度越大并且药柱表面压强也越大.采取倾斜切割方式为佳.验证了仿真方案的有效性和实用性.

  9. Rapid Confined Mixing Using Transverse Jets Part 2: Multiple Jets

    Science.gov (United States)

    Forliti, David; Salazar, David

    2012-11-01

    An experimental study has been conducted at the Air Force Research Laboratory at Edwards Air Force Base to investigate the properties of confined mixing devices that employ transverse jets. The experiment considers the mixing of water with a mixture of water and fluorescein, and planar laser induced fluorescence was used to measure instantaneous mixture fraction distributions in the cross section view. Part one of this study presents the scaling law development and results for a single confined transverse jet. Part two will describe the results of configurations including multiple transverse jets. The different regimes of mixing behavior, ranging from under to overpenetration of the transverse jets, are characterized in terms of a new scaling law parameter presented in part one. The level of unmixedness, a primary metric for mixing device performance, is quantified for different jet diameters, number of jets, and relative flow rates. It is apparent that the addition of a second transverse jet provides enhanced scalar uniformity in the main pipe flow cross section compared to a single jet. Three and six jet configurations also provide highly uniform scalar distributions. Turbulent scalar fluctuation intensities, spectral features, and spatial eigenfunctions using the proper orthogonal decomposition will be presented. Distribution A: Public Release, Public Affairs Clearance Number: 12656.

  10. Numerical simulations of interacting surfactant-laden jets in microfluidic channels

    Science.gov (United States)

    Goel, Garvit; Yang, Junfeng; Cabral, Joao; Matar, Omar

    2014-11-01

    We consider the dynamics of jets of surfactant solution in oil under microfluidic confinement. Previous experimental work has demonstrated the occurrence of ``jetting'' and ``dripping'' flow regimes depending on the choice of oil and water flow rates, viscosity ratio, and surfactant concentration. To take into account the influence of soluble surfactant on the behaviour of the jets, we present a computational fluid dynamics (CFD) approach which uses the Volume-of-Fluid method capturing the interface topology accurately with minimal mass loss. This approach accounts for sorption kinetics, Marangoni stresses, diffusion, and surface dilation. This method is incorporated into a CFD code to study the jetting and dripping regimes in a microfluidics channel. The modelling results are validated against experimental measurements. EPSRC Programme Grant, MEMPHIS, EP/K0039761/1, and Grant Number EP/J010502/1.

  11. The water-born protein pheromones of the polar protozoan ciliate, Euplotes nobilii: Coding genes and molecular structures

    Science.gov (United States)

    Vallesi, Adriana; Alimenti, Claudio; Di Giuseppe, Graziano; Dini, Fernando; Pedrini, Bill; Wüthrich, Kurt; Luporini, Pierangelo

    2010-08-01

    The protozoan ciliate Euplotes nobilii found in Antarctic and Arctic coastal waters relies on secretion of water-soluble cell type-specific signal proteins (pheromones) to regulate its vegetative growth and sexual mating. For three of these psychrophilic pheromones we previously determined the three-dimensional structures by nuclear magnetic resonance (NMR) spectroscopy with protein solutions purified from the natural sources, which led to evidence that their adaptation to cold is primarily achieved by increased flexibility through an extension of regions free of regular secondary structures, and by increased exposure of negative charges on the protein surface. Then we cloned the coding genes of these E. nobilii pheromones from the transcriptionally active cell somatic nucleus (macronucleus) and characterized the full-length sequences. These sequences all contain an open reading frame of 252-285 nucleotides, which is specific for a cytoplasmic pheromone precursor that requires two proteolytic cleavages to remove a signal peptide and a pro segment before release of the mature protein into the extracellular environment. The 5‧ and 3‧ non-coding regions are two- to three-fold longer than the coding region and appear to be tightly conserved, probably in relation to the inclusion of intron sequences destined to be alternatively removed to play key regulatory roles in the mechanism of the pheromone gene expression.

  12. Applicability of GALE-86 Codes to Integral Pressurized Water Reactor designs

    Energy Technology Data Exchange (ETDEWEB)

    Geelhood, Kenneth J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rishel, Jeremy P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-06-01

    This report describes work that Pacific Northwest National Laboratory is doing to assist the U.S. Nuclear Regulatory Commission (NRC) Office of New Reactors (NRO) staff in their reviews of applications for nuclear power plants using new reactor core designs. These designs include small integral PWRs (IRIS, mPower, and NuScale reactor designs), HTGRs, (pebble-bed and prismatic-block modular reactor designs) and SFRs (4S and PRISM reactor designs). Under this specific task, PNNL will assist the NRC staff in reviewing the current versions of the GALE codes and identify features and limitations that would need to be modified to accommodate the technical review of iPWR and mPower® license applications and recommend specific changes to the code, NUREG-0017, and associated NRC guidance. This contract is necessary to support the licensing of iPWRs with a near-term focus on the B&W mPower® reactor design. While the focus of this review is on the mPower® reactor design, the review of the code and the scope of recommended changes consider a revision of the GALE codes that would make them universally applicable for other types of integral PWR designs. The results of a detailed comparison between PWR and iPWR designs are reported here. Also included is an investigation of the GALE code and its basis and a determination as to the applicability of each of the bases to an iPWR design. The issues investigated come from a list provided by NRC staff, the results of comparing the PWR and iPWR designs, the parameters identified as having a large impact on the code outputs from a recent sensitivity study and the main bases identified in NUREG-0017. This report will provide a summary of the gaps in the GALE codes as they relate to iPWR designs and for each gap will propose what work could be performed to fill that gap and create a version of GALE that is applicable to integral PWR designs.

  13. Considerations and calculations on the breakup of jets and drops of melt related to premixing

    Energy Technology Data Exchange (ETDEWEB)

    Buerger, M.; Berg, E. von; Buck, M. [Inst. fuer Kernenergetik und Energiesysteme (IKE), Univ. of Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart (Germany)

    1998-01-01

    Various descriptions of jet and drop breakup are applied in premixing codes, presently. The main task is to check these descriptions over a wide range of conditions in order to assure extrapolation capabilities for the codes. Jet breakup under non-boiling conditions is relatively well described by IKEJET, based on Conte/Miles (CM) instability description and a relatively detailed stripping model, in contrast to using Kelvin/Helmholtz (KH) theory. Remaining open questions are elaborated. Especially, thick jet behavior with dominance of stripping even at small relative velocities must be distinguished from thin jets with coarse breakup. The application of IKEJET to cases with jet breakup under strong film boiling yielded significantly too little fragmentation. As a possible explanation line, multiphase effects on the wave growth and stripping are considered, due to entrainment of melt and water. Parametric checking calculations are performed with a strongly simplified approach for PREMIX and FARO experiments in order to reveal main effects and the possible physical explanation features as a basis for extended modelling. The results indicate that jet breakup may be essentially sufficient to explain the experimental behavior. Rather coalescence than further drop breakup may be expected. This is also indicated by calculations with IKE drop breakup models. (author)

  14. Removal of volatile iodine from gas bubbles rising in water pools: review and assessment of pool scrubbing codes

    Energy Technology Data Exchange (ETDEWEB)

    Polo, J.; Herranz, L.E.; Peyres, V.; Escudero, M. [CIEMAT, Nuclear Technology Institute, Madrid (Spain)

    1996-12-01

    During a hypothetical nuclear reactor accident with core damage the fission products released from the degrading fuel bundles often pass through aqueous beds before entering the containment, mitigating in part the source term. Several computer codes have been developed for predicting the fission product and aerosols removal in pool scrubbing scenarios. In addition to particle removal, these codes simulate the retention of some volatile iodine compounds. In this work a review of volatile iodine removal models included in SPARC and BUSCA codes is presented. Besides, the results and discussions of a validation of both codes against the available experimental data are summarized. SPARC and BUSCA codes model the diffusion of iodine toward the bubble interface by using the film penetration theory, which assumes a double layer gas-liquid at the interface. However, there are some differences between the two models, mainly related to the boundary conditions in the aqueous volume for the diffusion of molecular iodine. In SPARC, a set of fast reactions in the liquid phase control both the molecular iodine concentration in the pool and the partition coefficient of iodine at the interface. Thus, the aqueous chemistry plays an important role in the boundary conditions for the diffusion process. On the contrary, the BUSCA model has no chemical considerations at all, and assumes a null iodine concentration in the water bulk. Several sensitivity studies have been made in order to weight the effect of these differences. The variables examined in these studies were the pool temperature and the incoming iodine concentration in the pool. Additionally, sensitivity studies focused on the steam mass fraction of the injected gas were performed to study the effect of the different approach of both models for the condensation process. The results showed a different sensitivity of SPARC and BUSCA to the incoming concentration. (author) 5 tabs., 26 refs.

  15. Optimization of convective heat transfer coefficient in water jet cooled mirror%射流式水冷镜对流换热系数的优化

    Institute of Scientific and Technical Information of China (English)

    李斌; 焦路光; 刘亮; 李兰; 周琼; 袁圣付; 刘文广

    2011-01-01

    介绍了射流水冷技术并将其应用到高能激光器反射镜的冷却中,设计了射流式水冷镜.采用计算流体力学的方法,利用通用有限元软件ANSYS的流体分析模块FLOTRAN对单孔内射流进行了数值模拟,详细讨论了各孔参数对换热性能的影响.实现了孔参数的优化.结果表明:在水冷镜中采用射流技术可以获得很好的对流换热效果,换热系数可达100 KW/(m·K)以上,且具有结构简单、可控性强等特点.%The jet cooling technology was introduced and used in the cooling of high power laser mirror, then the water jet cooled mirror was designed.Computational fluid dynamics method was adopted to simulate the jet in a hole by the fluid analysis module FLOTRAN of the finite element analysis software ANSYS, then the influence on the capability of heat transfer of the parameters of the hole was discussed and optimization of the parameters was achieved.The results show that great capability of heat transfer can be achieved by using the jet cooling technology, with simple structure and good controllability, and the heat transfer coefficient can be higher than 100 kW/(m2 · K).

  16. Entropy Assessment on Direct Contact Condensation of Subsonic Steam Jets in a Water Tank through Numerical Investigation

    Directory of Open Access Journals (Sweden)

    Yu Ji

    2016-01-01

    Full Text Available The present article analyzes the dissipation characteristics of the direct contact condensation (DCC phenomenon that occurs when steam is injected into a water tank at a subsonic speed using a new modeling approach for the entropy generation over the calculation domain. The developed entropy assessment model is based on the local equilibrium hypothesis of non-equilibrium thermodynamics. The fluid flow and heat transfer processes are investigated numerically. To describe the condensation and evaporation process at the vapor-liquid interface, a phase change model originated from the kinetic theory of gas is implemented with the mixture model for multiphase flow in the computational fluid dynamics (CFD code ANSYS-FLUENT. The CFD predictions agree well with the published works, which indicates the phase change model combined with the mixture model is a promising way to simulate the DCC phenomenon. In addition, three clear stages as initial stage, developing stage and oscillatory stage are discriminated from both the thermal-hydraulic results and the entropy generation information. During different stages, different proportion of the entropy generation rate owing to heat transfer, viscous direct dissipation, turbulent dissipation and inner phase change in total entropy generation rate is estimated, which is favorable to deeper understanding the irreversibility of DCC phenomenon, designing and optimizing the equipment involved in the process.

  17. Differential absorption lidar measurements of atmospheric water vapor using a pseudonoise code modulated AlGaAs laser. Thesis

    Science.gov (United States)

    Rall, Jonathan A. R.

    1994-01-01

    Lidar measurements using pseudonoise code modulated AlGaAs lasers are reported. Horizontal path lidar measurements were made at night to terrestrial targets at ranges of 5 and 13 km with 35 mW of average power and integration times of one second. Cloud and aerosol lidar measurements were made to thin cirrus clouds at 13 km altitude with Rayleigh (molecular) backscatter evident up to 9 km. Average transmitter power was 35 mW and measurement integration time was 20 minutes. An AlGaAs laser was used to characterize spectral properties of water vapor absorption lines at 811.617, 816.024, and 815.769 nm in a multipass absorption cell using derivative spectroscopy techniques. Frequency locking of an AlGaAs laser to a water vapor absorption line was achieved with a laser center frequency stability measured to better than one-fifth of the water vapor Doppler linewidth over several minutes. Differential absorption lidar measurements of atmospheric water vapor were made in both integrated path and range-resolved modes using an externally modulated AlGaAs laser. Mean water vapor number density was estimated from both integrated path and range-resolved DIAL measurements and agreed with measured humidity values to within 6.5 percent and 20 percent, respectively. Error sources were identified and their effects on estimates of water vapor number density calculated.

  18. An ultrasound biomicroscopic and water jet ultrasound indentation method for detecting the degenerative changes of articular cartilage in a rabbit model of progressive osteoarthritis.

    Science.gov (United States)

    Wang, Yuexiang; Huang, Yan-Ping; Liu, Aijun; Wan, Wenbo; Zheng, Yong-Ping

    2014-06-01

    It is important to assess the early degeneration of articular cartilage associated with osteoarthritis (OA) for early intervention and treatment planning. Previously, we have developed a high frequency ultrasound and water jet indentation method for the morphologic, acoustic and mechanical assessment of articular cartilage, using the enzymatic digestion as a model of osteoarthritic degeneration. No naturally degenerated articular cartilage has been tested with the developed method. In this study, we aimed to determine the usefulness of the developed method for detecting the natural degeneration of articular cartilage in a standard surgical model of OA in rabbits. Forty adult New Zealand white female rabbits were used in this study, which included 30 experimental rabbits undergoing the right anterior cruciate ligament transection surgery and 10 control rabbits. At the 3rd, 6th, and 9th week post-surgery, 10 experimental rabbits were sacrificed, respectively, for assessment of the knee cartilage quality. The cartilage at the medial and lateral femoral condyles and tibial plateaus (four points) was measured by the high frequency ultrasound biomicroscopy, the water jet ultrasound indentation and a contact mechanical indentation test before a histopathologic analysis for grading of degeneration severity. Measured parameters were compared among different groups classified either by post-surgery time or by histopathologic grade. The results showed a general trend of increase for ultrasound roughness index and a general trend of decrease for integrated reflection coefficient, stiffness coefficient from water-jet indentation and Young's modulus (E) from the mechanical indentation with the increase of post-surgery time. Comparisons among groups with different histopathologic grades showed similar trend with the increase of degeneration severity. The water jet ultrasound indentation method was demonstrated to be an effective method to measure the mechanical properties of the

  19. 磨料水射流钻头破岩过程的力学分析%Mechanical analysis of rock breaking by an abrasive water jet bit

    Institute of Scientific and Technical Information of China (English)

    卢义玉; 沈晓莹; 汤积仁; 夏彬伟; 王景环

    2012-01-01

    The boss at the hole bottom is a key factor that limits drilling speed. The boss was eliminated and drilling speed increased by using an abrasive water jet bit to drill in hard rock. Force analysis shows that the mode of rock breaking during hard rock drilling by a three wings bit is by grinding. However, the mode is by cutting when an abrasive water jet is used. Hard rock drilling experiments showed that the drilling speed was 1. 57 times faster using an improved bit with reduced blade distance of the leading bit compared to the original three wings bit. At the same time torque increased by 11.3%, and the observed wear is serious. The drill- ing speed using an abrasive water jet bit is 3.72 times faster than the original three wings bit and the torque is reduced by 34.0% with no evident wear. Theoretical analysis and experimen- tal results showed that low drilling speeds and serious wear encountered while drilling in hard rock can be completely resolved by using an abrasive water jet bit.%研究发现钻孔孔底凸台是限制钻头钻进速度的关键因素,为了消除凸台,提高钻进速度,提出利用磨料水射流钻头破碎硬岩.对原三翼钻头和磨料水射流钻头破岩过程进行了受力分析得出原三翼钻头硬岩钻进时破岩方式为磨削,磨料水射流钻头破岩方式为切削.实验室硬岩钻进实验表明:缩小前导钻头刀片间距的改良型钻头钻进速度是原三翼钻头的1.57倍,扭矩比原三翼钻头增大了11.3%,且磨损加剧;磨料水射流钻头钻进速度是原三翼钻头的3.72倍,扭矩比原三翼钻头减小34.0%,未见明显磨损.理论分析和实验结果表明,磨料水射流钻头从根本上解决了硬岩钻进时速度慢,刀具磨损大的问题.

  20. Study on the Suf-mixed Abrasive Water Jet Cutting System%后混合磨料水射流切割系统的研究

    Institute of Scientific and Technical Information of China (English)

    胡东; 夏志华; 唐川林

    2013-01-01

    后混合磨料水射流是极具发展前景的一种冷态加工工艺。对后混合磨料射流切割机的工作原理及主体组成进行了分析,并针对IE-B型超高压水射流切割机所存在的不足进行了改进。结果表明:改进后的磨料水射流切割机解决了原有设备密封性能差、可靠性低、维护成本高等多方面的问题。%The suf-mixed abrasive water jet is a kind of promising cold processing technology. The principle and component parts of the suf-mixed abrasive water jet cutting system were introduced and analyzed,then some advises about the disadvantages of the super high pressure water cutting machine (Type:IE-B)were presented. The results show that the ameliorated equipment can work normal-ly,and the sealing characteristics,reliability and maintenance are improved effectively.

  1. Effects of the water level hydrated in NMMO on the physical properties of cellulose fiber in dry jet-wet spinning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D.B.; Lee, W.S.; Kim, B.C.; Jo, S.M.; Park, J.S. [Korea Institute of Science and Technology, Seoul (Korea, Republic of); Lee, Y.M. [Hanyang University, Seoul (Korea, Republic of)

    1998-03-01

    The effects of the amount of water hydrated in N-methylmorpholine N-oxide (NMMO) in dry jet-wet spinning of cellulose was investigated in terms of rheological properties of the spinning dope and the physical properties of the fiber. At the identical polymer concentration of 12 wt%, the solution of cellulose in 90.4 wt% NMMO gave higher viscosity and higher storage modulus (G`) than that in 86.7 wt% NMMO, which was more noticeable at 110 {sup o} C than at 12 {sup o} C. Decrease in the hydrated water level or increase in the air-gap or spin draw ratio increased such physical properties of the fiber as birefringence, initial modulus and tensile strength. The tensile fractured morphology revealed that the fiber from NMMO containing less water gave more fibrils resulting from higher orientation. Further, it produced thicker and longer fibrils when treated with an ultrasonic generator.

  2. Variable Jet Distance and Multi-Stage Cutting Head with Abrasive Water Jet%可变喷距磨料射流多级切割头研制与试验

    Institute of Scientific and Technical Information of China (English)

    周卫东; 夏柏如; 李罗鹏; 师伟

    2012-01-01

    应用磨料射流切割技术切除海上采油多层废弃井口时,面临的一个突出问题是切割外层套管和隔水管时喷距变大引起作业时间增加,导致作业成本高昂.基于缩短喷距的思路,设计了一种可变喷距磨料射流多级切割头,切割头上布置有固定喷嘴和长、短伸缩杆喷嘴,每种喷嘴具有相互独立的供液流道,因此切割头可提供3种工作模式,即固定喷嘴切割模式、短伸缩杆切割模式和长伸缩杆切割模式.施工作业时,采用投球的方式依次进行3种工作模式的转换.理论计算表明,使用φ3mm喷嘴时,长、短伸缩杆工作模式可分别将无因次喷距减小至使用固定喷嘴时的1/27与1/16.7,有效提高了射流的能量利用率.地面试验表明,可变喷距多级切割头使用方便,流道转换可靠,比普通固定喷嘴式切割头切割效率显著提高,可大幅度缩短作业时间,降低作业成本.%The crucial problem in AWJ(abrasive water jet) technique for cutting subsea oil production multi-layer abandoned wellheads is that cutting of external casing and marine riser leads to increase of operation time and excessively high cost. The paper designed a variable jet distance and multi-stage AWJ cutting head with fixed nozzles, long and short expansion link nozzles, which were different in distance and had independent fluid channels,based on the thinking to reduce jet distance. Therefore,cutting head had three operating modes,which were the fixed nozzles for cutting mode,short expansion link for cutting mode and long expansion link for cutting modes. The three working modes were switched by delivering two balls in order in the process of operation. After theoretical calculation,with 3 mm nozzle,long expansion link mode and short long expansion link mode could reduce the dimensionless jet distance to 1/16. 7 and 1/27 compared with that of using fixed nozzles. It was useful to improve the utilization of jet energy. At the same

  3. Heat transfer due to impinging double free circular jets

    Directory of Open Access Journals (Sweden)

    Mohamed A. Teamah

    2015-09-01

    Full Text Available The heat transfer and fluid flow between a horizontal heated plate and impinging circular double jets were studied experimentally. The parameters investigated are the Reynolds number of each jet and jet-to-jet spacing. Experiments are carried out covering a range for Reynolds number from 7100 to 30,800 for each jet, the dimensionless jet-to-jet spacing from 22.73 to 90.1. During experimental phases, the right jet Reynolds number was higher than the left jet Reynolds number. The isothermal contours were plotted for different cases as well as the distribution of water film thickness over the heated plate. The results indicated that increasing the Reynolds number of one jet than the other increases both local and average Nusselt numbers. In addition, increasing the jet-to-jet spacing at the same Reynolds number increases the average Nusselt number.

  4. Determination of the δ2H and δ18O of soil water and water in plant matter; RSIL lab code 1700

    Science.gov (United States)

    Revesz, Kinga M.; Buck, Bryan; Coplen, Tyler B.

    2012-01-01

    The purpose of the Reston Stable Isotope Laboratory lab code 1700 is to determine the δ2H/1H), abbreviated as δ2H, and the δ18O/16O), abbreviated as δ18O, of soil water and water in plant matter. This method is based on the observation that water and toluene form an azeotropic mixture at 84.1 °C. This temperature is substantially lower than the boiling points of water (100 °C) and toluene (110 °C), but water and toluene are immiscible at ambient temperature. The water content of a soil or plant is determined by weighing, drying, and reweighing a small amount of sample. Sufficient sample to collect 3 to 5 milliliters of water after distillation is loaded into a distillation flask. Sufficient toluene is added so that the sample is immersed throughout the entire distillation to minimize evaporation of water, which would affect the δ2H and δ18O values. The mixture of sample and toluene is heated in a flask to its boiling point (84.1 °C) so that water from the sample and toluene can distill together into a specially designed collection funnel. The temperature of 84.1 °C is maintained until the water has been quantitatively transferred to the collection funnel, at which time the temperature is raised to the boiling point of the remaining component (toluene, 110 °C). The collection funnel is maintained at ambient temperature so that the sample water and toluene can be separated physically. After separation, the sample water is purified by addition of paraffin wax to the container with the sample water, capping the container, and heating to approximately 60 °C to melt the wax. Trace amounts of toluene will dissolve in the wax, purifying the sample water for isotopic analysis. The isotopic composition of the purified water is then determined by equilibration with gaseous hydrogen or carbon dioxide, followed by dual-inlet isotope-ratio mass spectrometry. Because laser-absorption spectrometry is sensitive to organic compounds, such as trace toluene remaining in

  5. Cooling water system thermal performance analysis using the COCO computer code

    Energy Technology Data Exchange (ETDEWEB)

    Hom, J.; Jakub, R.M.; Durkosh, D.E. [Westinghouse Electric Corp., Pittsburgh, PA (United States). Energy Systems Business Unit

    1996-10-01

    Westinghouse Energy Systems Business Unit (ESBU) has worked with electric utility personnel to analyze the thermal performance of essential cooling water systems at nuclear generating stations. The primary goal of these analyses has been to demonstrate the operability of the cooling water systems during postulated limiting post-accident operation. In previous cooling water system thermal analyses, peak containment operating conditions were generally used as input assuming steady-state conditions. This approach is conservative as it does not take into account the improvement in containment conditions and cooling water system temperatures over time. This approach can, also, lead to an inconsistent set of assumptions between the two distinct analyses which may result in overly conservative calculated system operating conditions. These conditions inevitably impose unnecessary restrictions on cooling water system operation. Over the last few years, Westinghouse ESBU has coupled both the containment integrity and the cooling water system thermal calculations into an integrated analysis. This allows the use of a consistent set of input parameters and assumptions in the calculation of limiting cooling water system operating conditions. This approach has been successfully used to increase system operating margins. This paper provides an overview of this coupled thermal analysis along with examples of where increased operating margins can be applied.

  6. Jet quenching via jet collimation

    CERN Document Server

    Casalderrey-Solana, J; Wiedemann, U

    2011-01-01

    The strong modifications of dijet properties in heavy ion collisions measured by ATLAS and CMS provide important constraints on the dynamical mechanisms underlying jet quenching. In this work, we show that the transport of soft gluons away from the jet cone - jet collimation - can account for the observed dijet asymmetry with values of $\\hat{q}\\, L$ that lie in the expected order of magnitude. Further, we show that the energy loss attained through this mechanism results in a very mild distortion of the azimuthal angle dijet distribution.

  7. Emerging jets

    Energy Technology Data Exchange (ETDEWEB)

    Schwaller, Pedro; Stolarski, Daniel [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TH-PH Div.; Weiler, Andreas [European Organization for Nuclear Research (CERN), Geneva (Switzerland). TH-PH Div.; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2015-02-15

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.

  8. Emerging Jets

    CERN Document Server

    Schwaller, Pedro; Weiler, Andreas

    2015-01-01

    In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilit...

  9. Stationary Relativistic Jets

    CERN Document Server

    Komissarov, S S; Lyutikov, M

    2015-01-01

    In this paper we describe a simple numerical approach which allows to study the structure of steady-state axisymmetric relativistic jets using one-dimensional time-dependent simulations. It is based on the fact that for narrow jets with v~c the steady-state equations of relativistic magnetohydrodynamics can be accurately approximated by the one-dimensional time-dependent equations after the substitution z=ct. Since only the time-dependent codes are now publicly available this is a valuable and efficient alternative to the development of a high-specialized code for the time-independent equations. The approach is also much cheaper and more robust compared to the relaxation method. We tested this technique against numerical and analytical solutions found in literature as well as solutions we obtained using the relaxation method and found it sufficiently accurate. In the process, we discovered the reason for the failure of the self-similar analytical model of the jet reconfinement in relatively flat atmospheres a...

  10. Calculation of releases of radioactive materials in gaseous and liquid effluents from boiling water reactors (BWR-GALE Code)

    Energy Technology Data Exchange (ETDEWEB)

    Bangart, R.L.; Bell, L.G.; Boegli, J.S.; Burke, W.C.; Lee, J.Y.; Minns, J.L.; Stoddart, P.G.; Weller, R.A.; Collins, J.T.

    1978-12-01

    The calculational procedures described in the report reflect current NRC staff practice. The methods described will be used in the evaluation of applications for construction permits and operating licenses docketed after January 1, 1979, until this NUREG is revised as a result of additional staff review. The BWR-GALE (Boiling Water Reactor Gaseous and Liquid Effluents) Code is a computerized mathematical model for calculating the release of radioactive material in gaseous and liquid effluents from boiling water reactors (BWRs). The calculations are based on data generated from operating reactors, field tests, laboratory tests, and plant-specific design considerations incorporated to reduce the quantity of radioactive materials that may be released to the environment.

  11. The preliminary thermal–hydraulic analysis of a water cooled blanket concept design based on RELAP5 code

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guanghuai; Peng, Changhong; Guo, Yun, E-mail: guoyun79@ustc.edu.cn

    2016-11-01

    Highlights: • The superheated steam and PWR schemes are analyzed by RELAP5 code. • The influence of non-uniform heating sources is include. • A supposed slow flow decrease case is discussed and the PWR scheme is better. - Abstract: Water cooled blanket (WCB) is very important in the conceptual design and energy transfer in future fusion power plant. One conceptual design of WCB is under computational testing. RELAP5 code, which is mature and often used in transient analysis in Pressurizer water reactor (PWR), is selected as the simulation tool. The complex inner flow channels and heat sources are simplified according to its thermal–hydraulic characteristics. Then the nodal model for REALP5 is built for approximating the conceptual design. Two typical operating plans, superheated steam scheme and PWR scheme, are analyzed. After some adjustments of the inlet flow resistance coefficients of some flow channels, the reasonable stable conditions of both operation plans can be obtained. The stable fluid and wall temperature distributions and pressure drops are studied. At last, a supposed slow flow decreasing is discussed under two operating conditions separately. According to present results, the superheated steam scheme still needs to be further optimized. The PWR scheme shows a very good safety feature.

  12. Dicing of high-power white LEDs in heat sinks with the water jet-guided laser

    Science.gov (United States)

    Mai, Tuan Anh; Housh, Roy; Brulé, Arnaud; Richerzhagen, Bernold

    2007-02-01

    High-brightness LEDs are compound semiconductor devices and distinguish themselves from conventional LEDs by their exceptional luminosity. Today they are increasingly used as light sources, replacing conventional incandescent and fluorescent lamp technologies. HB LEDs are difficult to manufacture, as they must be grown by sophisticated epitaxial growth techniques such as MOCVD. They are packaged like power semiconductors, using surface mount technology and thermal pads. After having been successfully applied to GaN scribing for side-emitting LEDs, the Laser MicroJet (R) is used today for cutting heat sinks of HB white LEDs. Due to the high-emitted light power, the generated heat must be dissipated through a heat sink. Materials typically employed are metals with high heat conductivity, notably CuW and molybdenum. Applying the Laser MicroJet (R) the achieved cutting quality in these metals is outstanding - smooth edges, no contamination, no burrs, no heat damage, no warping - all this at high speed.

  13. High-speed singulation of electronic packages using a frequency-doubled Nd:YAG laser in a water jet and realization of a 200-W green laser

    Science.gov (United States)

    Wagner, Frank R.; Hu, Wentao; Spiegel, Akos; Vago, Nandor; Richerzhagen, Bernold

    2003-07-01

    Each electronic chip is packaged in order to connect the integrated circuit and the printed circuit board. In consequence high-speed singulation of packages is an important step in the manufacturing process of electronic devices. The widely used technique of abrasive sawing encounters problems due to the combination of different materials used in packages such as copper and mold compound. The sawing blade rapidly blunts because of the copper adhering to the saw blade and covering the diamonds. In fact, the abrasive saw, well adapted to silicon wafer sawing, has problems to adapt to package materials. It has already been shown that the water jet guided laser can be used for efficient high quality singulation of leadframe based packages. In this technique a low-pressure water jet guides the laser beam like an optical fiber, providing efficient cooling of the cutting kerf at exactly the point that was heated during the laser pulse. We present new cutting results using a frequency doubled Nd:YAG laser with 100 W average power, and the combination setup for generating a 200 W green laser beam. The timing between the two lasers can be precisely controlled.

  14. 磨料水射流切割面粗糙度研究%Research on Surface Roughness in Abrasive Water Jet Cutting

    Institute of Scientific and Technical Information of China (English)

    苗新刚; 武美萍; 缪小进

    2016-01-01

    It was investigated traverse speed and abrasive mass flow rate during abrasive water jet cuttingof aluminum on surface roughness. GMT garnet was used as abrasive material with 80 mesh. The experimental results show that traverse speed has the greatest effect on the surface roughness at the bottom of the cut. It was also researched the correlation between the surface roughness and other abrasive water jet cutting variables.%对在磨料水射流切割过程中进给速度和磨料流量两点进行了讨论。磨料颗粒采用直径为80目的石榴石。测量了切割不同深度的粗糙度。实验结果表明:对切割表面影响最大的是切割速度。同时也研究了切割面粗糙度和磨料水射流其他参数之间的关系。

  15. Technology of Water-jet and Its Application in Medicine%水刀技术及其在医学领域的应用

    Institute of Scientific and Technical Information of China (English)

    郭新; 张西正; 徐晓莹; 郭春; 陈明东; 黄跃青; 崔智慧

    2009-01-01

    The technology of water-jet is an advanced technology of cold cutting which is widely used in industry, espe-cially in the cutting of metal, glass, ceramics and paper. Its character and classification are introduced, especially basic prineiple, development and application. The technology of water-jet will paly an important role in medicine.%水刀技术是一项先进的冷切割技术,在工业上应用十分广泛,主要用于切割金属、玻璃陶瓷和纸等.由于其选择性和保护性切割等优点,被引入医学领域并应用于临床.简述了其分类、特点,着重论述了医用水刀的基本原理、发展及其应用,指出水刀技术在医学领域必将发挥更为重要的作用.

  16. Significant issues and changes for ANSI/ASME OM-1 1981, part 1, ASME OMc code-1994, and ASME OM Code-1995, Appendix I, inservice testing of pressure relief devices in light water reactor power plants

    Energy Technology Data Exchange (ETDEWEB)

    Seniuk, P.J.

    1996-12-01

    This paper identifies significant changes to the ANSI/ASME OM-1 1981, Part 1, and ASME Omc Code-1994 and ASME OM Code-1995, Appendix I, {open_quotes}Inservice Testing of Pressure Relief Devices in Light-Water Reactor Power Plants{close_quotes}. The paper describes changes to different Code editions and presents insights into the direction of the code committee and selected topics to be considered by the ASME O&M Working Group on pressure relief devices. These topics include scope issues, thermal relief valve issues, as-found and as-left set-pressure determinations, exclusions from testing, and cold setpoint bench testing. The purpose of this paper is to describe some significant issues being addressed by the O&M Working Group on Pressure Relief Devices (OM-1). The writer is currently the chair of OM-1 and the statements expressed herein represents his personal opinion.

  17. Combinatorial materials research applied to the development of new surface coatings VI: An automated spinning water jet apparatus for the high-throughput characterization of fouling-release marine coatings.

    Science.gov (United States)

    Stafslien, Shane J; Bahr, James A; Daniels, Justin W; Wal, Lyndsi Vander; Nevins, Jonathan; Smith, Jeremy; Schiele, Kris; Chisholm, Bret

    2007-07-01

    Large numbers of coatings can be generated very quickly using a combinatorial high-throughput approach. Rapid screening assays are typically required to adequately evaluate and down select coating candidates to identify promising compositions. An automated, spinning water jet apparatus was developed to rapidly characterize the adhesion strength of marine organisms to coating surfaces. Coating arrays are cast in multiwell plates and subjected to a jet of water of controlled pressure and duration. Array plates are manipulated by a robotic arm to facilitate accurate and repeatable water jet treatments. Jet pressures of 40-688 kPa can be generated and precisely maintained by computer control. A five axis robotic arm selects plates from three plate stacking hotels yielding a total of 39 plates or 936 individual coating samples for each experimental run. All robotic instructions, process parameters, and data are stored and controlled by the computer. The large plate handling capacity offered by the robotic system enables the analysis of a wide variety of coatings for "fouling-release" properties. A brief example demonstrating the capability of the automated water jet apparatus to evaluate marine bacterial adhesion to coating surfaces is provided.

  18. Applied Research on High-Pressure Water Jet Cutting Technology in Anti-Terrorist%高压水射流切割技术在反恐中的应用研究

    Institute of Scientific and Technical Information of China (English)

    孙义柯; 龚烈航; 罗晓凯

    2015-01-01

    In this article, the main principle of high-pressure water jet cutting technology is described with focusing on appli-cation of the high-pressure abrasive water jet in counter-terrorism operations. A pre-mixed abrasive high pressure water jet device that is applicative in the counter-terrorism operations is researched and designed so as to provide a kind of protection for the counter-terrorism operations.%介绍了高压水射流切割技术的主要原理,重点介绍了磨料高压水射流在反恐行动中的应用,并研究设计了一种在反恐行动中适用的前混合磨料高压水射流装置,为反恐行动的顺利进行提供一种行动上的保障.

  19. Optimal Control of Water Jet Cutting System Based on Pressure Sensor%基于压力传感器的水刀切割优化控制系统

    Institute of Scientific and Technical Information of China (English)

    徐礼龙; 赵德安; 于雯

    2012-01-01

    Considering the fact that water jetting speed, pressure, sand diameter, friction velocity and nozzle' 8 geometric parameters can influence the quality of cutting parts respectively, of which, only water jetting speed can be controlled freely, a pressure sensor-based optimal control system for water-jetting cutting process was proposed.%水刀切割工件质量与水刀的速度、喷流压力、砂粒直径、流量摩擦流速及喷嘴的几何参数等有关,但是只有速度可以随意控制,笔者设计一种基于压力传感器的水刀切割优化系统,解决了水射流技术存在的缺点.

  20. Structure and intermolecular vibrations of 7-azaindole-water 2:1 complex in a supersonic jet expansion: Laser-induced fluorescence spectroscopy and quantum chemistry calculation

    Indian Academy of Sciences (India)

    Montu K Hazra; Moitrayee Mukherjee; V Ramanathan; Tapas Chakraborty

    2012-01-01

    Laser-induced fluorescence spectra of a 2:1 complex between 7-azaindole and water, known as `non-reactive dimer’ of the molecule, have been measured in a supersonic jet expansion. The dispersed fluorescence spectrum of the electronic origin band of the complex shows a very large number of low-frequency vibrational features corresponding to different intermolecular modes of the complex in the ground electronic state. Geometries of several possible isomeric structures of the complex and their vibrational frequencies at harmonic approximation were calculated by electronic structure theory method at MP2/6-31G∗∗ level. An excellent agreement is observed between the measured and calculated intermolecular vibrational mode frequencies for the energetically most favoured structure of the complex, where the water molecule is inserted within one of the two N$\\cdots$H-N hydrogen bonds of the 7AI dimer.

  1. Crust behavior and erosion rate prediction of EPR sacrificial material impinged by core melt jet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gen; Liu, Ming, E-mail: ming.liu@mail.xjtu.edu.cn; Wang, Jinshi; Chong, Daotong; Yan, Junjie

    2017-04-01

    Highlights: • A numerical code was developed to analyze melt jet-concrete interaction in the frame of MPS method. • Crust and ablated concrete layer at UO{sub 2}-ZrO{sub 2} melt and concrete interface periodically developed and collapsed. • Concrete surface temperature fluctuated around a low temperature and ablation temperature. • Concrete erosion by Fe-Zr melt jet was significantly faster than that by UO{sub 2}-ZrO{sub 2} melt jet. - Abstract: Sacrificial material is a special ferro-siliceous concrete, designed in the ex-vessel core melt stabilization system of European Pressurized water Reactor (EPR). Given a localized break of RPV lower head, the melt directly impinges onto the dry concrete in form of compact jet. The concrete erosion behavior influences the failure of melt plug, and further affects melt spreading. In this study, a numerical code was developed in the frame of Moving Particle Semi-implicit (MPS) method, to analyze the crust behavior and erosion rate of sacrificial concrete, impinged by prototypic melt jet. In validation of numerical modeling, the time-dependent erosion depth and erosion configuration matched well with the experimental data. Sensitivity study of sacrificial concrete erosion indicates that the crust and ablated concrete layer presented at UO{sub 2}-ZrO{sub 2} melt and concrete interface, whereas no crust could be found in the interaction of Fe-Zr melt with concrete. The crust went through stabilization-fracture-reformation periodic process, accompanied with accumulating and collapsing of molten concrete layer. The concrete surface temperature fluctuated around a low temperature and ablation temperature. It increased as the concrete surface layer was heated to melting, and dropped down when the cold concrete was revealed. The erosion progression was fast in the conditions of small jet diameter and large concrete inclination angle, and it was significantly faster in the erosion by metallic melt jet than by oxidic melt jet.

  2. Study on Water Jet Noise Reduction Mechanism during Single-nozzle Rocket Launch%单喷管火箭发射喷水降噪机理研究

    Institute of Scientific and Technical Information of China (English)

    陈劲松; 吴新跃; 张国栋; 曾玲芳; 贺建华

    2015-01-01

    Aiming at the launch technical characteristics of strap-on launch vehicle, a simplified test system used for water jet noise reduction mechanism simulation is proposed and the preliminary test study has been finished. The analysis of water jet noise reduction simulation flow field data shows that once the low-speed, normal temperature liquid water jet flow injects into high-speed gaseous jet flow, liquid water is atomized instantaneously. Momentum of high-speed gaseous jet flow generates and energy exchange happens. The sound transformation ability that makes the high-speed gaseous jet flow form high sound intensity noise is weakened. It is also shown that the concentration of the atomized flow is uniform during the follow-up propelling process, changing or even cutting off the transmission path of original jet flow noise. The frequency analysis of water jet noise reduction simulation test shows that within wide frequency spectrum, water jet has the ability to suppress noise, particularly for whistler-type noise.%针对捆绑式运载火箭发射技术特点,提出并研发相对简化的单喷管火箭发射喷水降噪机理模拟试验系统,完成单喷管火箭发射喷水降噪机理初步试验研究.对喷水降噪模拟试验流场数据、资料的分析表明,低速常温液态水射流喷入高速气态喷流后,液态水瞬间雾化,实现高速气态喷流动量、能量交换,高速气态喷流形成高声强噪声的声效转换能力由此下降.雾化水汽在后续推进过程浓度十分均匀,改变甚至切断原喷流噪声传播途径.发射喷水降噪模拟试验噪声频谱分析表明,喷水条件下喷水具备宽频范围内抑制噪声能力,同时,喷水抑制喷流噪声中啸音能力突出.

  3. Sensitivity analysis of CFD code FLUENT-12 for supercritical water in vertical bare tubes

    Energy Technology Data Exchange (ETDEWEB)

    Farah, A.; Haines, P.; Harvel, G.; Pioro, I., E-mail: amjad.farah@yahoo.com, E-mail: patrickjhaines@gmail.com, E-mail: glenn.harvel@uoit.ca, E-mail: igor.pioro@uoit.ca [Univ. of Ontario Inst. of Technology, Faculty of Energy Systems and Nuclear Science,Oshawa, Ontario (Canada)

    2012-07-01

    The ability to use FLUENT 12 or other CFD software to accurately model supercritical water flow through various geometries in diabatic conditions is integral to research involving coal-fired power plants as well as Supercritical Water-cooled Reactors (SCWR). The cost and risk associated with constructing supercritical water test loops are far too great to use in a university setting. Previous work has shown that FLUENT 12, specifically realizable k-ε model, can reasonably predict the bulk and wall temperature distributions of externally heated vertical bare tubes for cases with relatively low heat and mass fluxes. However, sizeable errors were observed for other cases, often those which involved large heat fluxes that produce deteriorated heat transfer (DHT) regimes. The goal of this research is to gain a more complete understanding of how FLUENT 12 models supercritical water cases and where errors can be expected to occur. One control case is selected where expected changes in bulk and wall temperatures occur and they match empirical correlations' predictions, and the operating parameters are varied individually to gauge their effect on FLUENT's solution. The model used is the realizable k-ε, and the parameters altered are inlet pressure, mass flux, heat flux, and inlet temperature. (author)

  4. Role of long non-coding RNAs in bacterial cold water disease pathogenesis in rainbow trout

    Science.gov (United States)

    Bacterial cold water disease (BCWD) caused by Flavobacterium psychrophilum is one of the major causes of mortality in salmonids. Three genetic lines of rainbow trout designated as ARS-Fp-R (resistant), ARS-Fp-C (control) and ARS-Fp-S (susceptible) have significant differences in survival rate follow...

  5. Development of a multiphysics analysis system for sodium-water reaction phenomena in steam generators of sodium-cooled fast reactors

    Science.gov (United States)

    Uchibori, Akihiro; Kurihara, Akikazu; Ohshima, Hiroyuki

    2015-12-01

    A multiphysics analysis system for sodium-water reaction phenomena in a steam generator of sodium-cooled fast reactors was newly developed. The analysis system consists of the mechanistic numerical analysis codes, SERAPHIM, TACT, and RELAP5. The SERAPHIM code calculates the multicomponent multiphase flow and sodium-water chemical reaction caused by discharging of pressurized water vapor. Applicability of the SERAPHIM code was confirmed through the analyses of the experiment on water vapor discharging in liquid sodium. The TACT code was developed to calculate heat transfer from the reacting jet to the adjacent tube and to predict the tube failure occurrence. The numerical models integrated into the TACT code were verified through some related experiments. The RELAP5 code evaluates thermal hydraulic behavior of water inside the tube. The original heat transfer correlations were corrected for the tube rapidly heated by the reacting jet. The developed system enables evaluation of the wastage environment and the possibility of the failure propagation.

  6. ALMA Observations of the Water Fountain Pre-Planetary Nebula IRAS 16342-3814: High-Velocity Bipolar Jets and an Expanding Torus

    Science.gov (United States)

    Sahai, R.; Vlemmings, W.H.T.; Gledhill, T.; Sánchez Contreras, C.; Lagadec, E.; Nyman, L-Å; Quintana-Lacaci, G.

    2017-01-01

    We have mapped 12CO J=3–2 and other molecular lines from the “water-fountain” bipolar pre-planetary nebula (PPN) IRAS 16342-3814 with ∼0⋅″35 resolution using ALMA. We find (i) two very high-speed knotty, jet-like molecular outflows, (ii) a central high-density (> few × 106 cm−3), expanding torus of diameter 1300 AU, and (iii) the circumstellar envelope of the progenitor AGB, generated by a sudden, very large increase in the mass-loss rate to > 3.5 × 10−4 M⊙ yr−1 in the past ~455 yr. Strong continuum emission at 0.89 mm from a central source (690 mJy), if due to thermally-emitting dust, implies a substantial mass (0.017 M⊙) of very large (~mm-sized) grains. The measured expansion ages of the above structural components imply that the torus (age~160 yr) and the younger high-velocity outflow (age~110 yr) were formed soon after the sharp increase in the AGB mass-loss rate. Assuming a binary model for the jets in IRAS 16342, the high momentum rate for the dominant jet-outflow in IRAS 16342 implies a high minimum accretion rate, ruling out standard Bondi-Hoyle-Lyttleton wind accretion and wind Roche lobe overflow (RLOF) models with white-dwarf or main-sequence companions. Most likely, enhanced RLOF from the primary or accretion modes operating within common envelope evolution are needed. PMID:28191303

  7. ALMA Observations of the Water Fountain Pre-planetary Nebula IRAS 16342-3814: High-velocity Bipolar Jets and an Expanding Torus

    Science.gov (United States)

    Sahai, R.; Vlemmings, W. H. T.; Gledhill, T.; Sánchez Contreras, C.; Lagadec, E.; Nyman, L.-Å; Quintana-Lacaci, G.

    2017-01-01

    We have mapped 12CO J = 3–2 and other molecular lines from the “water fountain” bipolar pre-planetary nebula (PPN) IRAS 16342-3814 with ∼0.″35 resolution using Atacama Large Millimeter/submillimeter Array. We find (i) two very high-speed knotty, jet-like molecular outflows; (ii) a central high-density (> {few}× {10}6 cm‑3), expanding torus of diameter 1300 au; and (iii) the circumstellar envelope of the progenitor AGB, generated by a sudden, very large increase in the mass-loss rate to > 3.5× {10}-4 M⊙ yr‑1 in the past ∼455 years. Strong continuum emission at 0.89 mm from a central source (690 mJy), if due to thermally emitting dust, implies a substantial mass (0.017 M⊙) of very large (∼millimeter-sized) grains. The measured expansion ages of the above structural components imply that the torus (age ∼160 years) and the younger high-velocity outflow (age ∼110 years) were formed soon after the sharp increase in the AGB mass-loss rate. Assuming a binary model for the jets in IRAS 16342, the high momentum rate for the dominant jet-outflow in IRAS 16342 implies a high minimum accretion rate, ruling out standard Bondi–Hoyle–Lyttleton wind accretion and wind Roche-lobe overflow (RLOF) models with white-dwarf or main-sequence companions. Most likely, enhanced RLOF from the primary or accretion modes operating within common-envelope evolution are needed.

  8. 多喷嘴射水式喷射器加热性能分析%Heating performance analysis of multi-nozzle water-jet steam ejector

    Institute of Scientific and Technical Information of China (English)

    童明伟; 蔡琴; 白秀娟

    2011-01-01

    This paper developes a heating coefficient model to study the heating performance of multi-nozzle water-jet steam ejector. It analyzes the factors of heating performance, and explores the relationships between the heating performance and different operating parameters theoretically and experimentally. The results show that the heating performance of multi-nozzle water-jet steam ejector is very good. The heating coefficient decreases with the increase of the inlet water temperature, and increases with the increase of the steam pressure and ejecting coefficient. The relationships between heating performance of ejector and different operating parameters by calculation and experiment are in good agreement.%为研究多喷嘴射水式喷射器的加热性能,提出了分析喷射器加热系数的计算模型,对喷射器加热性能的影响因素进行了分析,并根据理论分析和实验数据得出了不同运行参数对其加热性能的影响规律.研究结果表明,多喷嘴射水式喷射器具有很好的加热性能,喷射器的加热系数随入口水温的升高而减小,随蒸汽压力和引射系数的升高而增大,并且计算和实验得到的各运行参数对喷射器加热性能的影响规律是基本一致的.

  9. Faraday Conversion in Turbulent Blazar Jets

    CERN Document Server

    MacDonald, Nicholas R

    2016-01-01

    Low ($\\lesssim 3\\%$) levels of circular polarization (CP) detected at radio frequencies in the relativistic jets of some blazars can provide insight into the underlying nature of the jet plasma. CP can be produced through linear birefringence, in which initially linearly polarized emission produced in one region of the jet is altered by Faraday rotation as it propagates through other regions of the jet with various magnetic field orientations. Marscher has recently begun a study of jets with such magnetic geometries with the Turbulent Extreme Multi-Zone (TEMZ) model, in which turbulent plasma crossing a standing shock in the jet is represented by a collection of thousands of individual plasma cells, each with distinct magnetic field orientation. Here we develop a radiative transfer scheme that allows the numerical TEMZ code to produce simulated images of the time-dependent linearly and circularly polarized intensity at different radio frequencies. In this initial study, we produce synthetic polarized emission...

  10. Numerical simulation on influence of jet angle on jets characteristics in flowing ambient fluid

    Institute of Scientific and Technical Information of China (English)

    ZHOU Feng; SUN Zhao-chen; LIANG Shu-xiu

    2008-01-01

    Based on the stress-algebraic model, the turbulent buoyant jet with variable density was studied by the relation between density and concentration. A simple expression for buoyancy coefficient was proposed. The governing equations of turbulent buoyant jet with variable density were closed by introducing the expression of?and the relation between density and concentration. Numerical results for the jet axis with density difference a-gree well with experimental ones. By finite volume method, the 2 - D vertical jet's flow field with different jet angles was studied. The analysis of the relation among the vortex center, the position of separation point and jet angles shows that the circumfluence field is the largest when the jet angle is 90? The area turbulent kinetic en-ergy kA is proposed and the relationship between mixing intensity and jet angles is analyzed based on it. Results show that the jet angle of is the optimum condition for jet water mixing with environment water;and the reduced rate of difference between the centerline density of jet and the density of ambient water is the largest at the jet angle of 90?

  11. Mean droplet size and local velocity in horizontal isothermal free jets of air and water, respectively, viscous liquid in quiescent ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Al Rabadi, S.; Friedel, L. [Fluid Mechanics Institute, Technical University of Hamburg-Harburg (Germany); Al Salaymeh, A. [Mechanical Engineering Department, University of Jordan (Jordan)

    2007-01-15

    Measurements using two-dimensional Phase Doppler Anemometry as well as high speed cinematography in free jets at several nozzle exit pressures and mass flow rates, show that the Sauter mean droplet diameter decreases with increasing air and liquid-phase mass flow ratio due to the increase of the air stream impact on the liquid phase. This leads to substantial liquid fragmentation, respectively primary droplet breakup, and hence, satellite droplet formation with small sizes. This trend is also significant in the case of a liquid viscosity higher than that of water. The increased liquid viscosity stabilizes the droplet formation and breakup by reducing the rate of surface perturbations and consequently droplet distortions, ultimately also leading, in total, to the formation of smaller droplets. The droplet velocity decreases with the nozzle downstream distance, basically due to the continual air entrainment and due to the collisions between the droplets. The droplet collisions may induce further liquid fragmentation and, hence, formation of a number of relatively smaller droplets respectively secondary breakup, or may induce agglomeration to comparatively larger liquid fragments that may rain out of the free jet. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  12. Data on the densification during sintering of binder jet printed samples made from water- and gas-atomized alloy 625 powders

    Directory of Open Access Journals (Sweden)

    Amir Mostafaei

    2017-02-01

    Full Text Available Binder jet printing (BJP is a metal additive manufacturing method that manufactures parts with complex geometry by depositing powder layer-by-layer, selectively joining particles in each layer with a polymeric binder and finally curing the binder. After the printing process, the parts still in the powder bed must be sintered to achieve full densification (A. Mostafaei, Y. Behnamian, Y.L. Krimer, E.L. Stevens, J.L. Luo, M. Chmielus, 2016; A. Mostafaei, E. Stevens, E. Hughes, S. Biery, C. Hilla, M. Chmielus, 2016; A. Mostafaei, Y. Behnamian, Y.L. Krimer, E.L. Stevens, J.L. Luo, M. Chmielus, 2016 [1–3]. The collected data presents the characterization of the as-received gas- and water-atomized alloy 625 powders, BJP processing parameters and density of the sintered samples. The effect of sintering temperatures on the microstructure and the relative density of binder jet printed parts made from differently atomized nickel-based superalloy 625 powders are briefly compared in this paper. Detailed data can be found in the original published papers by authors in (A. Mostafaei, J. Toman, E.L. Stevens, E.T. Hughes, Y.L. Krimer, M. Chmielus, 2017 [4].

  13. An Open Software Platform for Sharing Water Resource Models, Code and Data

    Science.gov (United States)

    Knox, Stephen; Meier, Philipp; Mohamed, Khaled; Korteling, Brett; Matrosov, Evgenii; Huskova, Ivana; Harou, Julien; Rosenberg, David; Tilmant, Amaury; Medellin-Azuara, Josue; Wicks, Jon

    2016-04-01

    The modelling of managed water resource systems requires new approaches in the face of increasing future uncertainty. Water resources management models, even if applied to diverse problem areas, use common approaches such as representing the problem as a network of nodes and links. We propose a data management software platform, called Hydra, that uses this commonality to allow multiple models using a node-link structure to be managed and run using a single software system. Hydra's user interface allows users to manage network topology and associated data. Hydra feeds this data directly into a model, importing from and exporting to different file formats using Apps. An App connects Hydra to a custom model, a modelling system such as GAMS or MATLAB or to different file formats such as MS Excel, CSV and ESRI Shapefiles. Hydra allows users to manage their data in a single, consistent place. Apps can be used to run domain-specific models and allow users to work with their own required file formats. The Hydra App Store offers a collaborative space where model developers can publish, review and comment on Apps, models and data. Example Apps and open-source libraries are available in a variety of languages (Python, Java and .NET). The App Store can act as a hub for water resource modellers to view and share Apps, models and data easily. This encourages an ecosystem of development using a shared platform, resulting in more model integration and potentially greater unity within resource modelling communities. www.hydraplatform.org www.hydraappstore.com

  14. Simulations of Turbulent Momentum and Scalar Transport in Confined Swirling Coaxial Jets

    Science.gov (United States)

    Shih, Tsan-Hsing; Liu, Nan-Suey; Moder, Jeffrey P.

    2015-01-01

    This paper presents the numerical simulations of confined three-dimensional coaxial water jets. The objectives are to validate the newly proposed nonlinear turbulence models of momentum and scalar transport, and to evaluate the newly introduced scalar APDF and DWFDF equation along with its Eulerian implementation in the National Combustion Code(NCC). Simulations conducted include the steady RANS, the unsteady RANS (URANS), and the time-filtered Navier-Stokes (TFNS); both without and with invoking the APDF or DWFDF equation.

  15. Transient analysis of water slug discharge in PWR safety/relief valve piping. [WATSLUG code

    Energy Technology Data Exchange (ETDEWEB)

    Van Duyne, D.A.; Hsieh, J.S.; Shave, D.F.

    1981-01-01

    The sudden discharge of the water loop seal, which is often present upsteam of pressurizer safety and relief valves, creates large momentum and inertia forces on the piping segments downstream of the valve. This paper provides a brief discussion of the commonly available control-volume calculation techniques, a description of the governing equations and a recently developed computer routine (WATSLUG) for their solution, and a review of results calculated using this method for a typical pressurizer safety and relief valve system. 8 refs.

  16. Model polymer etching and surface modification by a time modulated RF plasma jet: role of atomic oxygen and water vapor

    Science.gov (United States)

    Luan, P.; Knoll, A. J.; Wang, H.; Kondeti, V. S. S. K.; Bruggeman, P. J.; Oehrlein, G. S.

    2017-01-01

    The surface interaction of a well-characterized time modulated radio frequency (RF) plasma jet with polystyrene, poly(methyl methacrylate) and poly(vinyl alcohol) as model polymers is investigated. The RF plasma jet shows fast polymer etching but mild chemical modification with a characteristic carbonate ester and NO formation on the etched surface. By varying the plasma treatment conditions including feed gas composition, environment gaseous composition, and treatment distance, we find that short lived species, especially atomic O for Ar/1% O2 and 1% air plasma and OH for Ar/1% H2O plasma, play an essential role for polymer etching. For O2 containing plasma, we find that atomic O initiates polymer etching and the etching depth mirrors the measured decay of O atoms in the gas phase as the nozzle-surface distance increases. The etching reaction probability of an O atom ranging from 10-4 to 10-3 is consistent with low pressure plasma research. We also find that adding O2 and H2O simultaneously into Ar feed gas quenches polymer etching compared to adding them separately which suggests the reduction of O and OH density in Ar/O2/H2O plasma.

  17. Influences of Droplet Size Distribution on Demulsification Effect of Cavitation Water Jet%液滴粒径分布对空化射流破乳效果的影响

    Institute of Scientific and Technical Information of China (English)

    管金发; 邓松圣; 雷传超; 舒丹

    2016-01-01

    建立了空化射流破乳实验系统,确定了分析液滴粒径分布对空化射流破乳效果影响的实验方法,研究了液滴粒径分布对空化射流破乳效果的影响规律。结果表明:空化射流处理存在破乳和乳化两种相反的作用。对于含有较多大粒径液滴的模型乳化油废水而言,空化射流处理主要使模型乳化油废水进一步乳化,空化射流方法应用于含有较多大粒径液滴的模型乳化油废水破乳是不可行的;对于液滴粒径普遍较小的虹吸模型乳化油废水而言,空化射流处理能促进液滴的碰撞聚并,从而有利于虹吸模型乳化油废水的破乳,空化射流方法应用于液滴粒径普遍较小的虹吸模型乳化油废水的破乳具有一定的效果。%With the establishment of demulsification experiment system for cavitation water jet, the experimental method of analysis of droplet size distribution on demulsification effect of cavitation water jetis determined, followed by the experimental study of droplet size distribution on demulsification effect of cavitation water jet. Results show that there are two kinds of contrary effects for cavitation water jet treatment, named as demulsificationand emulsification, respectively. As far as the model emulsified oil waste⁃water containing a lot of large droplet size droplets is concerned, cavitation water jet treatment emulsifies it more fully. Namely, cavi⁃tation water jet method is inapplicable to demulsification of the model emulsified oil wastewater containing a lot of large droplet size droplets. As far as the siphoning model emulsified oil wastewater in which there are most small droplet size droplets is concerned, cavitation water jet treatment promotes the collision and coalescence of droplets and is good for the demulsification of siphoning model emulsified oil wastewater. And cavitation water jet method has a demulsification effect for siphoning model emulsified oil

  18. Numerical model of water flow and solute accumulation in vertisols using HYDRUS 2D/3D code

    Science.gov (United States)

    Weiss, Tomáš; Dahan, Ofer; Turkeltub, Tuvia

    2015-04-01

    boundary to the wall of the crack (so that the solute can accumulate due to evaporation on the crack block wall, and infiltrating fresh water can push the solute further down) - in order to do so, HYDRUS 2D/3D code had to be modified by its developers. Unconventionally, the main fitting parameters were: parameter a and n in the soil water retention curve and saturated hydraulic conductivity. The amount of infiltrated water (within a reasonable range), the infiltration function in the crack and the actual evaporation from the crack were also used as secondary fitting parameters. The model supports the previous findings that significant amount (~90%) of water from rain events must infiltrate through the crack. It was also noted that infiltration from the crack has to be increasing with depth and that the highest infiltration rate should be somewhere between 1-3m. This paper suggests a new way how to model vertisols in semi-arid regions. It also supports the previous findings about vertisols: especially, the utmost importance of soil cracks as preferential pathways for water and contaminants and soil cracks as deep evaporators.

  19. Jet Quenching via Jet Collimation

    CERN Document Server

    Casalderrey-Solana, Jorge; Wiedemann, Urs Achim

    2011-01-01

    The ATLAS Collaboration recently reported strong modifications of dijet properties in heavy ion collisions. In this work, we discuss to what extent these first data constrain already the microscopic mechanism underlying jet quenching. Simple kinematic arguments lead us to identify a frequency collimation mechanism via which the medium efficiently trims away the soft components of the jet parton shower. Through this mechanism, the observed dijet asymmetry can be accomodated with values of $\\hat{q}\\, L$ that lie in the expected order of magnitude.

  20. Study on Mechanism of Abrassive Water Jet Cutting%磨料水射流切割加工机理研究

    Institute of Scientific and Technical Information of China (English)

    苗新刚; 武美萍; 缪小进

    2016-01-01

    Mature processing method at present stage some bottleneck factors are more or less restricted to further improve the finish ma-chining accuracy, cutting abrasive water jet is applied to belong to a kind of new method, this article through to the cutting theory research and simulation analysis and experimental comparison, so as to further understand the maching mechanism.%现阶段成熟的加工方法或多或少存在一些瓶颈因素,制约了加工精度的进一步提升,磨料水射流应用于切割加工属于一种新型的方法,该文通过对切割进行理论研究及仿真分析与实验对比,从而深入了解切割加工机理。

  1. Image-guided robot-assisted prostate ablation using water jet-hydrodissection: initial study of a novel technology for benign prostatic hyperplasia.

    Science.gov (United States)

    Faber, Kenneth; de Abreu, Andre Luis Castro; Ramos, Patrick; Aljuri, Nikolai; Mantri, Surag; Gill, Inderbir; Ukimura, Osamu; Desai, Mihir

    2015-01-01

    To evaluate the safety and efficacy of a novel robotic tissue ablation system (PROCEPT Aquablation(™) System), in performing prostate ablation in a survival canine model. This novel technology uses a high-velocity saline stream that aims to selectively ablate prostatic glandular tissue while sparing collagenous structures such as blood vessels and capsule. Once the ablation is complete, a laser beam is captured by a low-pressure water jet to produce surface hemostasis. The extent and depth of ablation is predetermined by endoscopic and transrectal ultrasonography guidance. The procedure was performed in eight noncastrated male beagles aged 6 years or older (Acute 2, Chronic 6) through a previously created perineal urethrostomy. Aquablation time ranged from 40 to 84 seconds (mean 60.5 sec). There was no active bleeding in any of the dogs during or after Aquablation. Water jet-guided laser coagulation was used for purposes of monitoring its safety and efficacy. Five of the six dogs reached the predetermined 6-week mark. Complications included two dogs with infection successfully treated with antibiotics, a false passage created during catheter placement, and two bladder neck perforations (from mechanical insertion), one leading to euthanasia. Histologic evaluation at 6 weeks revealed a normal cellular architecture and full reepithelialization of the treatment cavity. We report the initial survival data in the animal model of a novel robotic device developed for managing symptomatic benign prostatic hyperplasia (BPH). Aquablation produces ablation of adenomatous elements while preserving collagenous structures and is a promising technology for surgical management of symptomatic BPH.

  2. The influence of the cutting density on the magnetic properties of non-oriented electrical steels cut through mechanical punching and water jet technologies

    Science.gov (United States)

    Paltanea, V.; Paltanea, G.; Gavrila, H.; Popovici, D.; Jiga, G.

    2017-02-01

    The use of high quality non-oriented electrical steel and of an innovative design for the magnetic cores of the electrical machines are very important, in order to minimize the value of the total energy losses. The energy losses are strongly influenced by the cutting technologies, and the producers of the electrical machines want to minimize the deterioration of the magnetic properties during the manufacturing process. The influence of the cutting density on the magnetic permeability and energy losses was analyzed and one can notice that these magnetic properties are strongly influenced by the cutting technologies. There were tested sheet samples of M400-50A and M700-50A industrial steel grades (thickness of 0.50 mm), cut through mechanical and water jet technologies. All samples have the length equal to 300 mm and the width of 30, 15, 10, 7.5 and 5 mm. The magnetic characterization was performed using a laboratory single strip tester, which can make measurements on samples with an area of 300 × 30 mm2. In order to have the standard width of 30 mm, there were put together side by side 2, 3, 4 and 6 pieces with different widths. The magnetic properties were analyzed at 1000 mT in the frequency range 10 ÷ 400 Hz. It was observed that the processing conditions must be controlled and optimized, in order to maintain a low deterioration of the magnetic properties of the non-oriented steels. In the case of water jet technology an increase of the cutting speed will be useful for the introduction of this method in the large scale manufacturing of the electrical machines.

  3. Evaluation of a newly developed piezo actuator-driven pulsed water jet system for liver resection in a surviving swine animal model.

    Science.gov (United States)

    Nakanishi, Chikashi; Nakano, Toru; Nakagawa, Atsuhiro; Sato, Chiaki; Yamada, Masato; Kawagishi, Naoki; Tominaga, Teiji; Ohuchi, Noriaki

    2016-01-25

    Preservation of the hepatic vessels while dividing the parenchyma is key to achieving safe liver resection in a timely manner. In this study, we assessed the feasibility of a newly developed, piezo actuator-driven pulsed water jet (ADPJ) for liver resection in a surviving swine model. Ten domestic pigs underwent liver resection. Parenchymal transection and vessel skeletonization were performed using the ADPJ (group A, n = 5) or an ultrasonic aspirator (group U, n = 5). The water jet was applied at a frequency of 400 Hz and a driving voltage of 80 V. Physiological saline was supplied at a flow rate of 7 ml/min. After 7 days, the animals were killed and their short-term complications were examined and compared between the two groups. No significant complications, such as massive bleeding, occurred in either group during the surgical procedures. The transection time per transection area was significantly shorter in group A than in group U (1.5 ± 0.3 vs. 2.3 ± 0.5 min/cm(2), respectively, P = 0.03). Blood loss per transection area was not significantly different between groups A and U (9.3 ± 4.2 vs. 11.7 ± 2.3 ml/cm(2), P = 0.6). All pigs in group A survived for 7 days. No postoperative bleeding or bile leakage was observed in any animal at necropsy. The present results suggested that the ADPJ reduces transection time without increasing blood loss. ADPJ is a safe and feasible device for liver parenchymal transection.

  4. Simultaneous Independent Multi-Weft Detector Applied to Water-Jet Looms%喷水织机用多纬同时分别检测装置

    Institute of Scientific and Technical Information of China (English)

    张振奇; 程玮燕

    2001-01-01

    喷水织机多纬同时引入时的织造,只有在纬丝全部同时检测时才能保证产品的质量,提高生产效率;但目前大部分织机上没有此检测装置。文章在对喷水织机原有纬丝检测装置的结构进行全面分析之后,结合其他无梭织机的纬丝检测装置的结构特点,设计了一种利用纺丝机上的感丝器进行检测的装置,经试用,安全可靠,造价低廉,不失为一种有意义的探索,可供其他无梭织机借鉴。%During multi-weft weaving by water-jet loom, only all wefts aresimultaneously detected, can the product quality and high productivity be ensured. However, such detecting devices are unavailable for most of current looms. Through thorough analyses on the structure of the existing weft detectors for water-jet loom and in combination with the structural features of weft detectors for other shuttleless looms, a detecting device is designed on the basis of the yarn detector of spinning machine. It proves to be safe, reliable and low in cost through trial application, offering reference for other shuttleless looms.

  5. 射流式碳化硅水冷镜数值模拟%Numerical Simulation of Water Jet Cooled SiC Mirror

    Institute of Scientific and Technical Information of China (English)

    李斌; 焦路光; 刘亮; 李兰; 周琼; 袁圣付; 刘文广

    2011-01-01

    将射流水冷技术应用到高能激光器反射镜的冷却中,设计了射流式碳化硅水冷镜.利用通用有限元分析软件ANSYS的流体分析模块FLOTRAN,建立了流体对流换热系数和压力计算的二维模型,在验证模型可靠性的基础上计算了一定参数下的换热系数和压力分布.利用ANSYS中的多物理场分析模块,建立了水冷镜形变计算的三维模型,计算了相应的镜体温度和形变分布,比较了不同材料和不同类型水冷镜的性能.计算结果表明,射流式碳化硅水冷镜可以获得很小的镜面形变,同时具有结构简单、冷却均匀性好、抗压性好等优点,在高能激光器中具有较广阔的应用前景.%Jet cooling technology is used in mirror cooling of high power lasers and water jet cooled mirror is designed based on this. 2D model is built and validated to calculate the convective heat transfer coefficient and pressure of liquid under certain parameters by fluid analysis module FLOTRAN in finite element analysis software ANSYS. 3D model is built to calculate corresponding temperature and deformation distribution of the mirror by the module of multi-physics in ANSYS, and the performance comparisons of different materials and different cooling methods are made. The results show that water jet cooled SiC mirror exhibits small mirror deformation, simple structure,good cooling uniformity and good pressure characteristic, which has great prospects in the application of high power lasers.

  6. Rigidity FEA of cantilever of abrasive water jet machine tool based on ANSYS%基于ANSYS磨料水射流机床悬臂梁刚度的有限元分析

    Institute of Scientific and Technical Information of China (English)

    杜文正; 雷玉勇; 李劲松; 杨振; 郭逸伟

    2012-01-01

    目前二维半磨料水射流机床大多采用悬臂梁结构。悬臂梁是磨料水射流切割头及其附件的重要承载部件,其刚度直接影响机床的加工精度。针对磨料水射流机床的悬臂梁进行了三维建模,并基于ANSYS对其进行了模态和频率响应分析。分析的结果为磨料水射流机床的减振、防振提供了理论依据。%The cantilever structure was used in most abrasive water jet machine tools.The cantilever is an important component supporting the abrasive water jet cutting head as well as other accessories.Its rigidity directly affects the machining accuracy.A 3D model of the cantilever of the abrasive water jet machine tool was established,and modal analysis and frequency response analysis were carried out based on ANSYS.The analysis results offered theoretical references for vibration reduction and prevention of the abrasive water jet machine tool.

  7. Digital decoration by continuous ink jet system for ceramic products based in water inks; Decoracion digital sostenible de productos ceramicos mediante chorro de tinta continuo y tintas en base agua

    Energy Technology Data Exchange (ETDEWEB)

    Colores Ceramicos, S. A.; Talleres Foro, S. L.

    2010-07-01

    A new continuous ink jet system for digital ceramic decoration using water based dispersed ceramic pigment has been developed, that increases drastically the sustainability of the process. During the development of this work, different equipment for any application and the consumables and design tools have been also developed. (Author)

  8. Study on improving performance of airlift device by self-excited oscillation pulsed jet used in mining under water

    Institute of Scientific and Technical Information of China (English)

    YANG Lin; CAI Shu-peng; TANG Chuan-lin

    2008-01-01

    The feasibility of the nozzle of self-excited oscillation pulsed jet (SEOPJ) as the breaker and loosing device for the air-lift pump was researched.The dynamic characteristics of the SEOPJ to crush the hard clay and loose the layer of ore deposit were explored experimentally under the submerged condition.The results show that the SEOPJ not only effectively breaks the hard clay or loose the particles of sand on the placer bed,but also produces fluctuating uplift force acting on particles of sand.The oscillating cross flow caused by the SEOPJ makes particles of sand move to the end of the suction pipe easily.Energy efficency of the airlift and concentration of the solids for the solid-liquid mixture sucked by the air-lift pump are increased obviously with the breaker of SEOPJ.

  9. Study on improving performance of airlift device by self-excited oscillation pulsed jet used in mining under water

    Institute of Scientific and Technical Information of China (English)

    YANG Lin; CAI Shu-peng; TANG Chuan-lin

    2008-01-01

    The feasibility of the nozzle of self-excited oscillation pulsed jet (SEOPJ) as the breaker and loosing device for the air-lift pump was researched. The dynamic characteris-tics of the SEOPJ to crush the hard clay and loose the layer of ore deposit were explored experimentally under the submerged condition. The results show that the SEOPJ not only effectively breaks the hard clay or loose the particles of sand on the placer bed, but also produces fluctuating uplift force acting on particles of sand. The oscillating cross flow caused by the SEOPJ makes particles of sand move to the end of the suction pipe easily. Energy efficency of the airlift and concentration of the solids for the solid-liquid mixture sucked by the air-lift pump are increased obviously with the breaker of SEOPJ.

  10. Erosion Characteristics and Mechanisms of Cavitating Abrasive Water Jet under Confining Pressure%围压条件下空化磨料射流的冲蚀特性与机制分析

    Institute of Scientific and Technical Information of China (English)

    廖华林; 牛继磊; 易灿

    2012-01-01

    磨料射流在水利水电、石油工程和海洋资源开发等领域有着广泛的应用,研究射流的冲蚀特性和破坏物料机制对提高水射流利用效率具有重要意义。利用自行研制的实验装置,研究了围压条件下自振空化、文丘里和锥形3种喷嘴形成的磨料射流冲蚀特性,分析了空化磨料射流冲蚀物料的机制。结果表明:自振空化喷嘴和文丘里喷嘴的冲蚀效果优于锥形喷嘴,空化作用有助于提高磨料射流的冲蚀效果;磨料射流的冲蚀效率随围压的增大而降低,主要原因是围压对纯水射流和空化磨料射流的压力脉动和冲击力具有抑制作用。分析认为,空化磨料射流冲蚀破碎物料的机制主要包括冲蚀、气蚀和共混磨蚀3种作用。%Abrasive water jet is widely used in water resources and architectural engineering,oil and gas engineering and marine resources development. It is significant to study the erosion characteristics of the jet and material destruction mechanisms to improve the efficiency of water jet. Using the selfdeveloped device, the experiments were performed on abrasive water jet erosion characteristics formed by three types of nozzles including self-oscillating cavitation nozzle, Venturi nozzle, and cone-shaped nozzle under confining pressure. Destruction mechanisms of metal material were also analyzed. The results show that the erosion efficiencies of the self-oscillating cavitation nozzle and Venturi nozzle are higher than that of the cone-shaped nozzle ~ cavitation erosion can help improve the efficiency of abrasive water jet. Abrasive water jet erosion efficiency decreases with the confining pressure increasing, mainly due to the confining pressure inhibiting pressure pulse, cavitation effect, and impinging pressure. The mechanism of materials by cavitating abrasive water jet includes three roles of impact erosion, cavitation and their synergism.

  11. Experimental study of the influence of rotating speed on the performance of micro water jet pump%转速对微型喷水推进泵性能影响的试验研究

    Institute of Scientific and Technical Information of China (English)

    胡海鹏; 石海峡; 柴立平; 李绍旭; 夏天

    2016-01-01

    Hydraulic performance of micro water jet pump influences the efficiency of water jet propul-sion systems directly .In this paper ,based on the model of micro water jet pump with power of less than 400 W ,the motor characteristic under different rotating speeds was acquired by motor test ,the specialized test bench of external characteristic was built according to the features of low lift and large flow rate ,and then the key parameters such as pressure and flow were collected ,thus the characteris-tic curve of water jet pump under different rotating speeds could be achieved .The research results showed that the rotating speed had a prominent effect on the efficiency of water jet pump ,the optimal efficiency area moved towards large flow area and the peak of efficiency increased with the increase of rotating speed .Once the water jet pump was designed ,the work area with optimal efficiency could be found by the optimization control of rotating speed .Consequently the run duration of water jet pump under different applications could increase remarkably .%微型喷水推进泵的水力特性直接影响着喷水推进系统的效率。文章以功率小于400 W 的微型喷水推进泵为模型,通过电机试验得出电机在不同转速情况下的特性,并针对喷水推进泵大流量、低扬程的特点搭建专门外特性试验台,对压力、流量等参数进行测量采集,得出不同转速情况下喷水推进泵的特性曲线。研究结果表明,喷水推进泵的转速对效率有着重要的影响,随着转速的增加,最优效率向大流量区域偏移,效率峰值也随着转速的增加而增大。在喷水推进泵设计完成后可以通过转速的优化控制得出最优的效率工作区,提高不同应用环境下喷水推进泵的工作时间。

  12. Jet flow in steadily swimming adult squid.

    Science.gov (United States)

    Anderson, Erik J; Grosenbaugh, Mark A

    2005-03-01

    Although various hydrodynamic models have been used in past analyses of squid jet propulsion, no previous investigations have definitively determined the fluid structure of the jets of steadily swimming squid. In addition, few accurate measurements of jet velocity and other jet parameters in squid have been reported. We used digital particle imaging velocimetry (DPIV) to visualize the jet flow of adult long-finned squid Loligo pealei (mantle length, L(m)=27.1+/-3.0 cm, mean +/-S.D.) swimming in a flume over a wide range of speeds (10.1-59.3 cm s(-1), i.e. 0.33-2.06 L(m) s(-1)). Qualitatively, squid jets were periodic, steady, and prolonged emissions of fluid that exhibited an elongated core of high speed flow. The development of a leading vortex ring common to jets emitted from pipes into still water often appeared to be diminished and delayed. We were able to mimic this effect in jets produced by a piston and pipe arrangement aligned with a uniform background flow. As in continuous jets, squid jets showed evidence of the growth of instability waves in the jet shear layer followed by the breakup of the jet into packets of vorticity of varying degrees of coherence. These ranged from apparent chains of short-lived vortex rings to turbulent plumes. There was some evidence of the complete roll-up of a handful of shorter jets into single vortex rings, but steady propulsion by individual vortex ring puffs was never observed. Quantitatively, the length of the jet structure in the visualized field of view, L(j), was observed to be 7.2-25.6 cm, and jet plug lengths, L, were estimated to be 4.4-49.4 cm using average jet velocity and jet period. These lengths and an average jet orifice diameter, D, of 0.8 cm were used to calculate the ratios L(j)/D and L/D, which ranged from 9.0 to 32.0 and 5.5 to 61.8, respectively. Jets emitted from pipes in the presence of a background flow suggested that the ratio between the background flow velocity and the jet velocity was more

  13. Study on the breakup length of circular impinging jet

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Circular impinging jet, which is widely used in accelerated control cooling (ACC) equipment to accelerate the cooling of hot rolled plates, is subject to breakup, and may result in undesirable cooling effect. Therefore, the jet breakup should be avoided as possible in industrial production. The objective of this study is to find the relation of the processing parameters of the ACC equipment versus the breakup length of jet with weaker turbulence. To obtain quantitative findings, not only relative experimental study but also numerical simulation was carried out. For a weaker turbulent water jet, the breakup length increases with the increase of jet diameter, as well as with the jet velocity; jet diameter has a significant effect on the breakup length for a certain flow rate when compared with jet velocity; finally a suggested correlation of the jet breakup length versus jet Weber number is presented in this study.

  14. Underwater operation of a DBD plasma jet

    Science.gov (United States)

    Foster, John E.; Weatherford, Brandon; Gillman, Eric; Yee, Benjamin

    2010-04-01

    A plasma jet produced in water using a submerged ac excited electrode in a coaxial dielectric barrier discharge configuration was studied. Plasma jet formation was found to occur only while the source was submerged. Plasma jet operation was characterized with and without gas flow. It was found that over 60% of the discharge power was deposited into the water and did not vary appreciably with excitation frequency. Presumably the remaining power fraction went into excitation, ionization and local electrode heating. Emission spectra of the jet revealed nitrogen, hydrogen, hydroxyl and oxygen emission lines. Operation of the plasma jet in water containing the oxidation-reduction indicator methylene blue dye resulted in a marked clearing of the water as observed visually and with a spectrophotometer, suggesting plasma-induced chemical reactivity.

  15. Experiments with large diameter gravity driven impacting liquid jets

    Science.gov (United States)

    Storr, G. J.; Behnia, M.

    The phenomenon of a liquid jet released under gravity and falling through or impacting onto another liquid before colliding with an obstructing solid surface has been studied experimentally under isothermal conditions. Usually the jet diameter was sufficiently large to ensure jet coherency until collision. Direct flow visualization was used to study jets released into water pools with no air head space and jets impacting onto water pools after falling through an air head space. It is shown that distances predicting the onset of buoyancy and the entrainment of air using derivations from continuous plunging jets, are not applicable for impacting jets. The morphology of jet debris after collision with the solid surfaces correlates with the wetting properties of the jet liquid on the surface.

  16. Dichotomy of Solar Coronal Jets: Standard Jets and Blowout Jets

    Science.gov (United States)

    Moore, R. L.; Cirtain, J. W.; Sterling, A. C.; Falconer, D. A.

    2010-01-01

    By examining many X-ray jets in Hinode/XRT coronal X-ray movies of the polar coronal holes, we found that there is a dichotomy of polar X-ray jets. About two thirds fit the standard reconnection picture for coronal jets, and about one third are another type. We present observations indicating that the non-standard jets are counterparts of erupting-loop H alpha macrospicules, jets in which the jet-base magnetic arch undergoes a miniature version of the blowout eruptions that produce major CMEs. From the coronal X-ray movies we present in detail two typical standard X-ray jets and two typical blowout X-ray jets that were also caught in He II 304 Angstrom snapshots from STEREO/EUVI. The distinguishing features of blowout X-ray jets are (1) X-ray brightening inside the base arch in addition to the outside bright point that standard jets have, (2) blowout eruption of the base arch's core field, often carrying a filament of cool (T 10(exp 4) - 10(exp 5) K) plasma, and (3) an extra jet-spire strand rooted close to the bright point. We present cartoons showing how reconnection during blowout eruption of the base arch could produce the observed features of blowout X-ray jets. We infer that (1) the standard-jet/blowout-jet dichotomy of coronal jets results from the dichotomy of base arches that do not have and base arches that do have enough shear and twist to erupt open, and (2) there is a large class of spicules that are standard jets and a comparably large class of spicules that are blowout jets.

  17. Hydrodynamical Simulations of Colliding Jets: Modeling 3C 75

    Science.gov (United States)

    Molnar, S. M.; Schive, H.-Y.; Birkinshaw, M.; Chiueh, T.; Musoke, G.; Young, A. J.

    2017-01-01

    Radio observations suggest that 3C 75, located in the dumbbell shaped galaxy NGC 1128 at the center of Abell 400, hosts two colliding jets. Motivated by this source, we perform three-dimensional hydrodynamical simulations using a modified version of the GPU-accelerated Adaptive-MEsh-Refinement hydrodynamical parallel code (GAMER) to study colliding extragalactic jets. We find that colliding jets can be cast into two categories: (1) bouncing jets, in which case the jets bounce off each other keeping their identities, and (2) merging jets, when only one jet emerges from the collision. Under some conditions the interaction causes the jets to break up into oscillating filaments of opposite helicity, with consequences for their downstream stability. When one jet is significantly faster than the other and the impact parameter is small, the jets merge; the faster jet takes over the slower one. In the case of merging jets, the oscillations of the filaments, in projection, may show a feature that resembles a double helix, similar to the radio image of 3C 75. Thus we interpret the morphology of 3C 75 as a consequence of the collision of two jets with distinctly different speeds at a small impact parameter, with the faster jet breaking up into two oscillating filaments.

  18. Simulation and Analysis on the Influence Factors of Water Jet Impact Force Based on FLUENT%基于FLUENT的水射流冲击力影响因素仿真分析

    Institute of Scientific and Technical Information of China (English)

    叶建友; 吕彦明

    2014-01-01

    Based on water jet impact model,the jet impact numerical simulation and simulation analysis was carried out by FLUENT. The content include the effect of different jet pressures ,jet distances and the diameters of nozzle outlet on jet impact force and area. The results indicate that impact force increases with the increase of jet pressure ,decreases after first increase with the increase of target distance when other related factors was determined. The ratio of impact is approximately equal to the nozzle exit diameter ratio of the square. Jet impact area is related to the nozzle exit diameter ,its area is about 2.9 times of the exit zone.%基于水射流冲击模型,应用FLUENT流体分析软件对喷嘴射流冲击力数值模拟和仿真,得出不同的射流压强、喷距及喷嘴出口直径对射流冲击力及冲击作用区域的影响。结果表明:其他相关因素确定时,射流冲击力随着射流压强的增加而增大,随着喷距的增加先增大、后减小;不同喷嘴出口直径的射流冲击力的比值约为喷嘴出口直径的平方比,射流冲击的作用区域与喷嘴出口直径有关,其面积约为出口直径的2.9倍。

  19. Guidelines for selecting codes for ground-water transport modeling of low-level waste burial sites. Volume 2. Special test cases

    Energy Technology Data Exchange (ETDEWEB)

    Simmons, C.S.; Cole, C.R.

    1985-08-01

    This document was written for the National Low-Level Waste Management Program to provide guidance for managers and site operators who need to select ground-water transport codes for assessing shallow-land burial site performance. The guidance given in this report also serves the needs of applications-oriented users who work under the direction of a manager or site operator. The guidelines are published in two volumes designed to support the needs of users having different technical backgrounds. An executive summary, published separately, gives managers and site operators an overview of the main guideline report. Volume 1, titled ''Guideline Approach,'' consists of Chapters 1 through 5 and a glossary. Chapters 2 through 5 provide the more detailed discussions about the code selection approach. This volume, Volume 2, consists of four appendices reporting on the technical evaluation test cases designed to help verify the accuracy of ground-water transport codes. 20 refs.

  20. Study of counter current flow limitation model of MARS-KS and SPACE codes under Dukler's air/water flooding test conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Woong; Kim, Min Gil; Lee, Jeong Ik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Bang, Young Seok [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    In particular, CCFL(the counter current flow limitation) occurs in components such as hot leg, downcomer annulus and steam generator inlet plenum during LOCA which is possible to have flows in two opposite directions. Therefore, CCFL is one of the thermal-hydraulic models which has significant effect on the reactor safety analysis code performance. In this study, the CCFL model will be evaluated with MARS-KS based on two-phase two-field governing equations and SPACE code based on two-phase three-field governing equations. This study will be conducted by comparing MARS-KS code which is being used for evaluating the safety of a Korean Nuclear Power Plant and SPACE code which is currently under assessment for evaluating the safety of the designed nuclear power plant. In this study, comparison of the results of liquid upflow and liquid downflow rate for different gas flow rate from two code to the famous Dukler's CCFL experimental data are presented. This study will be helpful to understand the difference between system analysis codes with different governing equations, models and correlations, and further improving the accuracy of system analysis codes. In the nuclear reactor system, CCFL is an important phenomenon for evaluating the safety of nuclear reactors. This is because CCFL phenomenon can limit injection of ECCS water when CCFL occurs in components such as hot leg, downcomer annulus or steam generator inlet plenum during LOCA which is possible to flow in two opposite directions. Therefore, CCFL is one of the thermal-hydraulic models which has significant effect on the reactor safety analysis code performance. In this study, the CCFL model was evaluated with MARS-KS and SPACE codes for studying the difference between system analysis codes with different governing equations, models and correlations. This study was conducted by comparing MARS-KS and SPACE code results of liquid upflow and liquid downflow rate for different gas flow rate to the famous Dukler

  1. 微磨料水射流切割头装置设计与研究%Design and research on cutting head for micro abrasive water jet

    Institute of Scientific and Technical Information of China (English)

    刘克福; 雷玉勇; 蒋代君

    2011-01-01

    In traditional culling head for abrasive water jet,abrasives are usually fed into the cutting head by negative pressure, which is poor in re liability, non-uniform in suction,and unavailable precise in control of the abrasive flow rate.A new type of cutting head for micro abrasive water jet and its control sys-tem are designed based on screw pumping principle And an auger mechanism is used to feed the abrasives initiatively, which is driven by an electrical step motor and the rotating speed of the step motor is regulated through control pulse sent by MCU.The flow rate of abrasives and the rotating speed of step motor are cor-responding one by one.Therefore, the abrasives can be fed to the mixing chamber quantitatively and contin-uously so that the flow rate of abrasives can be precisely controlled.The method of setting one-way valve on the outlet duct of mixing chamber may prevent high pressure water from flowing into supply tank after the clogging of the nozzle, and thus the invalidation problem of the abrasive feed system is solved effectively.%传统磨料水射流切割头的磨料靠负压吸入,可靠性差、吸入不均匀、流量不能精确控制.采用螺杆泵输送原理,设计了一种新型微磨料水射流切割头装置及控制系统.该装置采用螺杆泵主动送料,螺杆由步进电机驱动,单片机发出的控制脉冲控制步进电机的转速,步进电机的转速与磨料流量一一对应,从而将磨料定量、连续地送到切割头混合腔,实现磨料流量的精确控制.在混合腔的排出通道上设置单向阀门,解决了啧嘴堵塞后高压水直接进入磨料罐引起磨料输送系统失效问题.

  2. ON THE SELF-SIMILARITY OF A JET IN CROSSFLOW

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The RNG k-ε turbulence model is adopted to investigate a turbulent round jet issuing into crossflow, with the Reynolds number at jet exit of Re=6000 and jet-to crossflow velocity ratio of r=8. With the CFD code, FLUENT, the relations of dimensional analysis are successfully reproduced and the calculated coefficients agree well with the experimental measurements of Wong (1991) and Chu (1996). The investigations are then taken on the velocity, stream function and vorticity at the far field of the jet. It shows that at least within the covered range herein, the jet at the far field is self-similar.

  3. Plasma Jet Modeling for PLX

    Science.gov (United States)

    Mason, Caroline F.; Mason, Rodney J.; Faehl, R. J.; Kirkpatrick, R. C.

    2011-10-01

    The implicit simulation code ePLAS has been applied to plasma jets generated with mini-rail guns for plasma production and compression aimed at use with PLX. The rails are typically planar, 2.5 cm apart and arranged to transport an initial 1 cm or wider vertical plasma fill some 10 cm into a void. The driving magnetic field is 3.2 T. The plasma singly ionized argon at 1017 cm-3. We use ePLAS in both its traditional implicit/hybrid form where it is restricted by an electron Courant time step, and in a new super-hybrid form that extracts the main electron moments from the E&B-field solutions. This provides numerical stability at ion Courant limits, for at least a 10 times larger time step, thus probing microsecond jet dynamics with computational economy. We examine possible field penetration at the cathode and anode gun electrodes. Cathode erosion and EMHD B - Field penetration are possible at lower jet densities. We examine jet transport beyond the gun, modeling possible ionization with either analytic or tabular EOSs. We study the merger of jets with ions represented as either fluids or particles. Work supported by the USDOE under SBIR GRANT DE-SC0004207.

  4. Task 3: PNNL Visit by JAEA Researchers to Participate in TODAM Code Applications to Fukushima Rivers and to Evaluate the Feasibility of Adaptation of FLESCOT Code to Simulate Radionuclide Transport in the Pacific Ocean Coastal Water Around Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo

    2013-03-29

    Four JAEA researchers visited PNNL for two weeks in February, 2013 to learn the PNNL-developed, unsteady, one-dimensional, river model, TODAM and the PNNL-developed, time-dependent, three dimensional, coastal water model, FLESCOT. These codes predict sediment and contaminant concentrations by accounting sediment-radionuclide interactions, e.g., adsorption/desorption and transport-deposition-resuspension of sediment-sorbed radionuclides. The objective of the river and coastal water modeling is to simulate • 134Cs and 137Cs migration in Fukushima rivers and the coastal water, and • their accumulation in the river and ocean bed along the Fukushima coast. Forecasting the future cesium behavior in the river and coastal water under various scenarios would enable JAEA to assess the effectiveness of various on-land remediation activities and if required, possible river and coastal water clean-up operations to reduce the contamination of the river and coastal water, agricultural products, fish and other aquatic biota. PNNL presented the following during the JAEA visit to PNNL: • TODAM and FLESCOT’s theories and mathematical formulations • TODAM and FLESCOT model structures • Past TODAM and FLESCOT applications • Demonstrating these two codes' capabilities by applying them to simple hypothetical river and coastal water cases. • Initial application of TODAM to the Ukedo River in Fukushima and JAEA researchers' participation in its modeling. PNNL also presented the relevant topics relevant to Fukushima environmental assessment and remediation, including • PNNL molecular modeling and EMSL computer facilities • Cesium adsorption/desorption characteristics • Experiences of connecting molecular science research results to macro model applications to the environment • EMSL tour • Hanford Site road tour. PNNL and JAEA also developed future course of actions for joint research projects on the Fukushima environmental and remediation assessments.

  5. Jet Car Track Site

    Data.gov (United States)

    Federal Laboratory Consortium — Located in Lakehurst, New Jersey, the Jet Car Track Site supports jet cars with J57 engines and has a maximum jet car thrust of 42,000 pounds with a maximum speed of...

  6. Test study and model analysis of cutting polysilicon ingot by micro-abrasive water jet%微磨料水射流对多品硅切割的试验研究与模型分析

    Institute of Scientific and Technical Information of China (English)

    李志荣; 封志明; 郭宗环

    2012-01-01

    笔者根据材料冲蚀磨损原理,分析探讨了微磨料水射流切割多晶硅硅锭的机理。并运用后混合微磨料射流切割装置,对多晶硅硅锭进行了单因素切割试验,从而获得了切割性能曲线。研究结果表明,微磨料水射流对多晶硅的切割完全可行,射流压力和横移速度是重要的试验数据。通过对高压磨料水射流切割挂能的预测和加工参数的优化,最终建立切割表面质量经验模型,根据模型分析得出射流压力、横移速度与切割质量之间的关系。%Based on the principle of material erosion and abrasion, the paper discussed the mechanism of cutting polysilicon ingot by water jet. The single-factor test of cutting polysilicon ingot by mixed micro-abrasive water jet device was carried out, and the cutting performance curves were obtained. The study results showed that cutting polysilicon by micro-abrasive water jet was feasible. Jet pressure and cross speed were important test data. At the time of increasing the cutting depth, the jet pressure could be a bit higher and the cross speed of the nozzle could be a bit lower, so as to enhance the cutting efficiency. After the prediction of high-pressure abrasive water jet cutting performance and the optimization of machining parameters, the experiential model of cutting surface quality was built, and the relationshi[a among jet pressure, cross speed and cutting quality were identified.

  7. Determination of the δ15N and δ18O of nitrate in water; RSIL lab code 2900

    Science.gov (United States)

    Coplen, Tyler B.; Qi, Haiping; Revesz, Kinga; Casciotti, Karen; Hannon, Janet E.

    2007-01-01

    The purpose of the Reston Stable Isotope Laboratory (RSIL) lab code 2900 is to determine the δ15N and δ18O of nitrate (NO3-) in water. The δ15N and δ18O of the dissolved NO3- are analyzed by converting the NO3- to nitrous oxide (N2O), which serves as the analyte for mass spectrometry. A culture of denitrifying bacteria is used in the enzymatic conversion of the NO3- to N2O, which follows the pathway shown in equation 1: NO3- → NO2- → NO → 1/2 N2O (1) Because the bacteria Pseudomonas aureofaciens lack N2O reductive activity, the reaction stops at N2O, unlike the typical denitrification reaction that goes to N2. After several hours, the conversion is complete, and the N2O is extracted from the vial, separated from volatile organic vapor and water vapor by an automated -65 °C isopropanol-slush trap, a Nafion drier, a CO2 and water removal unit (Costech #021020 carbon dioxide absorbent with Mg(ClO4)2), and trapped in a small-volume trap immersed in liquid nitrogen with a modified Finnigan MAT (now Thermo Scientific) GasBench 2 introduction system. After the N2O is released, it is further purified by gas chromatography before introduction to the isotope-ratio mass spectrometer (IRMS). The IRMS is a Thermo Scientific Delta V Plus continuous flow IRMS (CF-IRMS). It has a universal triple collector, consisting of two wide cups with a narrow cup in the middle; it is capable of simultaneously measuring mass/charge (m/z) of the N2O molecule 44, 45, and 46. The ion beams from these m/z values are as follows: m/z = 44 = N2O = 14N14N16O; m/z = 45 = N2O = 14N15N16O or 14N14N17O; m/z = 46 = N2O = 14N14N18O. The 17O contributions to the m/z 44 and m/z 45 ion beams are accounted for before δ15N values are reported.

  8. Three-Dimensional Computations of Multiple Tandem Jets in Crossflow

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mixing and merging characteristics of multiple tandem jets in crossflow are investigated by use of the Computational Fluid Dynamics (CFD) code FLUENT. The realizable k~ε model is employed for turbulent closure of the Reynolds-averaged Navier-Stokes equations. Numerical experiments are performed for 1-, 2- and 4-jet groups, for jet-to-crossflow velocity ratios of R=4.2~16.3. The computed velocity and scalar concentration field are in good agreement with experiments using Particle Image Velocimetry (PIV) and Laser Induced Fluorescence (LIF), as well as previous work. The results show that the leading jet behavior is similar to a single free jet in crossflow, while all the downstream rear jets have less bent-over jet trajectories-suggesting a reduced ambient velocity for the rear jets. The concentration decay of the leading jet is greater than that of the rear jets. When normalized by appropriate crossflow momentum length scales, all jet trajectories follow a universal relation regardless of the sequential order of jet position and the number of jets. Supported by the velocity and trajectory measurements, the averaged maximum effective crossflow velocity ratio is computed to be in the range of 0.39 to 0.47.

  9. Optimization of Geometric Parameters of Focusing Tube for Water Jet Based on FLUENT%基于FLUENT的水射流聚焦管几何参数优化研究

    Institute of Scientific and Technical Information of China (English)

    王荣娟; 雷玉勇; 蒋代君; 戴良博; 卫排锋

    2011-01-01

    Based on the physic model of water jet cutting head, the two-dimensional mathematical model of flow field inside the cutting head was built using turbulent jet basic equation.The internal flow field of focusing tube was simulated using standard k-ε turbulence model based on FLUENT.The influence of the geometric parameters of focusing tube on distribution of water jet velocity field was researched.The results show that the contraction angle α, the ratio of length and diameter l/d, as well as the outlet diameter d of the focusing tube have a significant effects on the internal velocity field of water jet.When α = 20°, l/d = 70, the outlet jet velocity of the focusing tube is maximum.%基于水射流切割头的物理模型,根据湍流射流的基本方程建立了喷头内部流场的二维数学模型.采用标准k-ε湍流模型并应用FLUENT软件对聚焦管内部流场进行数值模拟,研究聚焦管几何参数对纯水射流速度流场的影响.研究结果表明:聚焦管人口收缩角α、长径比l/d和出口直径d对聚焦管内部速度流场有显著影响,当α=20°、l/d=70时,聚焦管出口射流速度最大.

  10. 水射流空化强化光催化氧化技术在养鱼污水处理中的应用初探%Treatment of fish culture wastewater via cavitating water jet assisted photocatalysis

    Institute of Scientific and Technical Information of China (English)

    徐娜; 贾金平; 王亚林; 李侃; 王晓宁

    2012-01-01

    研究了水射流空化强化TiO2光催化氧化技术处理养鱼污水的效果,同时考察了单独的水射流空化处理、光解处理、光催化氧化处理的效果.试验结果表明:水射流空化强化TiO2光催化技术处理养鱼污水0.5h后,杀菌率达97%;处理4h后,氨氮和COD的去除率分别达25%和29%.在降解氨氮和COD方面,水射流空化技术和TiO2光催化氧化技术结合表现出明显的协同效应.水射流空化强化光催化氧化是一种绿色无污染的工艺,而且高速射流产生的冲击波对水体可以起到增氧的作用,有利于养殖鱼类的生长.%Study the effect of water jet cavitation assisted TiO2 photocatalysis in treating fish culture wastewater.Meanwhile,investigate the effects of water jet cavitation,ultraviolet ( UV) radiation and photocatalysis treatment.The results showed that water jet cavitation assisted TiO2 photocatalysis treatment killed 97% bacteria within 0.5 hour,removed 25% ammonia nitrogen (NH3-N) and 29% chemical oxygen demand (COD) within 4 hours.In terms of degradation of NH3-N and COD,it abviously showed synergy effect with the combination of water jet cavitation technique and TiO2 photocatalysis technology.Water jet cavitation assisted TiO2 photocatalysis treatment is a kind of green pollution-free process,the shock wave caused by water jet cavitation have the function of increasing oxygen,which is beneficial to the breeding organisms.

  11. 高分子添加剂对磨料水射流切割质量的影响%Influence on Cutting Quality Generated by High Polymeric Additives Abrasive Water Jet

    Institute of Scientific and Technical Information of China (English)

    裴江红; 柏占伟

    2016-01-01

    通过磨料水射流和在磨料水射流中加入不同浓度高分子添加剂切割大理石的对比实验,测量了在不同工况下切缝表面不同位置测点的粗糙度。试验结果表明:在相同工况下,高分子添加剂磨料水射流较磨料水射流能减小切缝表面粗糙度,提高切缝表面质量;不同浓度高分子添加剂磨料射流对切缝表面粗糙度影响不一,存在最优浓度为3×10-4;磨料水射流切割中,走刀速度过慢和过快时获得切缝表面最小表面粗糙度的靶距较正常走刀速度大;高分子添加剂磨料射流切割中,不同走刀速度下获得切缝最小表面粗糙度的靶距趋向一致。%By the cutting marble contrast experiment between abrasive water jet and high polymeric additives added at different concentration of abrasive water jet , the surface roughness of the kerf in the different station was measured under different working condi -tions.The experiment result shows that high polymeric additives abrasive water jet can reduce the cutting seam surface roughness than abrasive water jet under same working condition , and the quality of cutting seam surface is improved .The high polymeric additive with different concentration has different influence on surface roughness , and the optimal concentration is 3×10-4 in this experiment .When the feeding speed is too slow or too fast in abrasive water jet cutting , the target distance for the minimum surface roughness is smaller than that of normal feeding speed .The target distance for the minimum surface roughness is consistent in high polymeric additives abra -sive water jet cutting in different feeding speed .

  12. Model of Loosen Blasting Assisted by High-Pressure Water Jet Spiral-Notch%高压水射流螺旋式切槽辅助松动爆破模型

    Institute of Scientific and Technical Information of China (English)

    粟登峰; 康勇; 王晓川; 郑丹丹

    2016-01-01

    A new technology of loosen blasting assisted by high-pressure water jet spiral-notch was put forward based on its unique advantages of water jet cutting, and the geometric model for water jet notched boreholes was established based on experiments. Furthermore, by employing fracture mechanics and Westergaard stress function method, the functions of complex variables was confirmed, and the stress field acted upon the spirally water jet notching borehole by quasi-static explosion gas was derived. The stress intensity factor of spiral-notch boreholes with high-pressure water jet was determined, and the loosening effect of loosen blasting assisted by high-pressure water jet spiral-notch was also analyzed. Finally, ANSYS/LS-DYNA was applied to verify the theoretical model, and the results of the numerical simulation are almost comparable to the model.%基于水射流独特的切割优势提出了高压水射流螺旋式切槽辅助松动爆破的新方法,实验研究了高压水射流切割煤岩体所形成缝槽的断口形貌并建立了其几何模型。在此基础上,基于断裂力学理论同时结合Westergaard方法,确定了复变函数,进而推导出爆生气体准静态作用下射流螺旋切槽孔的应力场公式,得到了射流螺旋切槽孔缝槽尖端应力强度因子计算公式,并分析了高压水射流切槽辅助松动爆破松动效应。最后,采用ANSYS/LS-DYNA数值模拟软件对该模型进行了验证,结果符合较好。

  13. STUDY ON FLUID MECHANICS OF HYPERVELOCITY LIQUID JETS

    Institute of Scientific and Technical Information of China (English)

    Shi Hong-hui; Tetsu Sakakura

    2003-01-01

    The fluid mechanics in the generation of hypervelocity water jets, light oil jets and glycerin jets was studied. Framing high-speed photography and single-shot photography were used to observe the jets directly. The purposes of this study is to investigate the disintegration and atomization processes at the velocity of 2km/s-3km/s as well as the auto-ignition and self-combustion of the light oil jets. Therefore, in the jet velocity measurement in addition to the high-speed photography, the results by other methods such as the laser beams cutting method and the shock wave detection using pressure transducers were also given. In the observation of the jets events, the illumination phenomenon was found, which may be regarded as the result of the auto-ignition and combustion of the light oil jets. Finally, the Munroe jet was studied.

  14. Size limits the formation of liquid jets during bubble bursting.

    Science.gov (United States)

    Lee, Ji San; Weon, Byung Mook; Park, Su Ji; Je, Jung Ho; Fezzaa, Kamel; Lee, Wah-Keat

    2011-06-21

    A bubble reaching an air-liquid interface usually bursts and forms a liquid jet. Jetting is relevant to climate and health as it is a source of aerosol droplets from breaking waves. Jetting has been observed for large bubbles with radii of R≫100 μm. However, few studies have been devoted to small bubbles (Rbubbles in sea water. Here we show that jet formation is inhibited by bubble size; a jet is not formed during bursting for bubbles smaller than a critical size. Using ultrafast X-ray and optical imaging methods, we build a phase diagram for jetting and the absence of jetting. Our results demonstrate that jetting in bubble bursting is analogous to pinching-off in liquid coalescence. The coalescence mechanism for bubble bursting may be useful in preventing jet formation in industry and improving climate models concerning aerosol production.

  15. Determination of the delta(15N/14N)of Ammonium (NH4+) in Water: RSIL Lab Code 2898

    Science.gov (United States)

    Hannon, Janet E.; Böhlke, John Karl

    2008-01-01

    The purpose of the technique described by Reston Stable Isotope Laboratory (RSIL) lab code 2898 is to determine the N isotopic composition, delta(15N/14N), abbreviated as d15N, of ammonium (NH4+) in water (freshwater and saline water). The procedure involves converting dissolved NH4+ into NH3 gas by raising the pH of the sample to above 9 with MgO and subsequently trapping the gas quantitatively as (NH4)2SO4 on a glass fiber (GF) filter. The GF filter is saturated with NaHSO4 and pressure sealed between two gas-permeable polypropylene filters. The GF filter 'sandwich' floats on the surface of the water sample in a closed bottle. NH3 diffuses from the water through the polypropylene filter and reacts with NaHSO4, forming (NH4)2SO4 on the GF filter. The GF filter containing (NH4)2SO4 is dried and then combusted with a Carlo Erba NC 2500 elemental analyzer (EA), which is used to convert total nitrogen in a solid sample into N2 gas. The EA is connected to a continuous-flow isotope-ratio mass spectrometer (CF-IRMS), which determines the relative difference in ratios of the amounts of the stable isotopes of nitrogen (15N and 14N) of the product N2 gas and a reference N2 gas. The filters containing the samples are compressed in tin capsules and loaded into a Costech Zero-Blank Autosampler on the EA. Under computer control, samples then are dropped into a heated reaction tube that contains an oxidant, where combustion takes place in a He atmosphere containing an excess of O2 gas. To remove S-O gases produced from the NaHSO4, a plug of Ag-coated Cu wool is inserted at the bottom of the reaction tube. Combustion products are transported by a He carrier through a reduction furnace to remove excess O2, toconvert all nitrogen oxides to N2, and to remove any remaining S-O gases. The gases then pass through a drying tube to remove water. The gas-phase products, mainly N2 and a small amount of background CO2, are separated by a gas chromatograph (GC). The gas is then introduced

  16. Self-induced sloshing excited by a horizontally injected plane jet

    Science.gov (United States)

    Saeki, Souichi; Madarame, Haruki; Okamoto, Koji

    2001-12-01

    A self-induced free-surface oscillation termed ‘self-induced sloshing’ was observed in a rectangular tank with a submerged and horizontally injected water jet. Self-induced sloshing is excited by the flow itself without any external force. Its behaviour was examined by experiment. The dominant frequency was found to be close to the first or second eigenvalue of fluid in a tank. The conditions of sloshing excitation were obtained for four tank geometries. They were called the ‘sloshing condition’, and defined in terms of inlet velocity and water level. Sloshing conditions were found to be strongly dependent on inlet velocity and tank geometry. A two-dimensional numerical simulation code was developed to simulate self-induced sloshing. The code was based on the boundary-fitted coordinate (BFC) method with height function. The numerical results were qualitatively verified by the experimental results, and were found to correlate well in terms of flow pattern, free-surface shape and sloshing conditions. In this study, sloshing growth was evaluated quantitatively using the simulation results. Oscillation energy supplied for the sloshing motion during a sloshing period (Econ) was calculated from simulation results. Sloshing growth was found to be strongly related to the sign and magnitude of Econ. The distribution of Econ showed that jet flow had a strong correlation with the sloshing growth. It was clarified that sloshing growth was primarily dependent on the spatial phase state of jet fluctuation. A governing parameter of self-induced sloshing, the modified Strouhal number Sts, was proposed on the basis of numerical evaluations of oscillation energy. The value of Sts suggests that one or two large vortices generated by jet fluctuations exist between the inlet and outlet during a sloshing period. When Sts is approximately either 1 (first stage) or 2 (second stage), self-induced sloshing occurs consistently in all experimental cases. The dependence of sloshing on

  17. Inclusive Jets in PHP

    Science.gov (United States)

    Roloff, P.

    Differential inclusive-jet cross sections have been measured in photoproduction for boson virtualities Q^2 < 1 GeV^2 with the ZEUS detector at HERA using an integrated luminosity of 300 pb^-1. Jets were identified in the laboratory frame using the k_T, anti-k_T or SIScone jet algorithms. Cross sections are presented as functions of the jet pseudorapidity, eta(jet), and the jet transverse energy, E_T(jet). Next-to-leading-order QCD calculations give a good description of the measurements, except for jets with low E_T(jet) and high eta(jet). The cross sections have the potential to improve the determination of the PDFs in future QCD fits. Values of alpha_s(M_Z) have been extracted from the measurements based on different jet algorithms. In addition, the energy-scale dependence of the strong coupling was determined.

  18. Evaluation of the Impact of Kerojet (trademark) Aquarius Water Scavenger Additive on the Thermal Stability of Jet A Fuels

    Science.gov (United States)

    2014-12-01

    Dubai at 40C and 100% humidity will potentially produce 20 liters (a little over 5 gallons) free water during the flight even if the aircraft fuel... moves within a sleeve. Movement of the spool causes clearances within the spool/sleeve assembly to change and thus, control flow through the valve...electrical-servo portion of the valve are amplified by system hydraulic pressures resulting in a substantial moving force being applied to a

  19. The collection of Adipose Derived Stem Cells using Water Jet Assisted Lipoplasty for their use in Plastic and Reconstructive Surgery: a preliminary study

    Directory of Open Access Journals (Sweden)

    Valeria Purpura

    2016-11-01

    Full Text Available The graft of autologous fat for the augmentation of soft tissue is a common practice frequently used in the field of plastic and reconstructive surgery. In addition, the presence of adipose derived stem cells (ASCs in adipose tissue stimulates the regeneration of tissue in which it is applied after the autologous fat grafting improving the final clinical results. Due to these characteristics, there is an increasing interest in the use of ASCs for the treatment of several clinical conditions. As a consequence, the use of clean room environment is required for the production of cell-based therapies. The present study is aimed to describe the biological properties of adipose tissue and cells derived from it cultured in vitro in clean room environment according to current regulation. The collection of adipose tissue was performed using the waterjet assisted liposuction in order to preserve an high cell viability increasing their chances of future use for different clinical application in the field of plastic and reconstructive surgery.

  20. An Electrosurgical Endoknife with a Water-Jet Function (Flushknife) Proves Its Merits in Colorectal Endoscopic Submucosal Dissection Especially for the Cases Which Should Be Removed En Bloc

    Science.gov (United States)

    Takeuchi, Yoji; Ishihara, Ryu; Iishi, Hiroyasu; Hanaoka, Noboru; Higashino, Koji; Uedo, Noriya

    2013-01-01

    Background. Previously, we reported that the Flushknife (electrosurgical endoknife with a water-jet function) could reduce the operation time of colorectal endoscopic submucosal dissection (ESD) however, suitable situation for the Flushknife was obscure. This subgroup analysis of a prospective randomized controlled trial was aimed to investigate the suitable situation for the Flushknife. Methods. A total of 48 superficial colorectal neoplasms that underwent ESD using either the Flexknife or the Flushknife in a referral center were enrolled. The differences of operation time between the Flexknife and the Flushknife groups in each subgroup (tumor size, location, and macroscopic type) were analyzed. Results. Median (95% CI) operation time calculated using survival curves was significantly shorter in the Flushknife group than in the Flexknife group (55.5 min [41, 78] versus 74.0 [57, 90] min; P = 0.039, Hazard Ratio HR: 0.53; 95% CI (0.29–0.97)). In particular, the HR in patients with laterally spreading tumors-nongranular type (LST-NG) in the Flushknife group was significantly smaller than in the Flexknife group (HR: 0.165→0.17; 95% CI (0.04–0.66)). There was a trend of decreasing HRs according to larger lesion size. Conclusions. The Flushknife proved its merits in colorectal ESD especially for the lesions which should be removed en bloc (LST-NG and large lesion). PMID:24174933

  1. Analysis of Morphology of Kerfs of Submerged Abrasive Water Jet%淹没磨料水射流切缝形貌研究

    Institute of Scientific and Technical Information of China (English)

    侯亚康; 毛桂庭; 阳宁

    2011-01-01

    分析研究了淹没磨料水射流对花岗岩切割所成的切缝,发现淹没状况下切缝断面存在一宽度常数区;利用Hurst指数和R/S分析法得出了切缝形成过程中的时间相关性与随机性,得出切缝底部不仅存在时间相关性,且随着进给速度的减小,随机性增强、相关性减弱的结论。%This paper mainly focued on analysing the kerf of submerged abrasive water jet cutting from which a width of the constant region was obversed.The author adopted the Hurst index and R/S analytical method to analyse and get the temporal correlation and random in the formation of the kerf,which randomness increases and correlation deteriorates as the feed rate decreases.

  2. An Electrosurgical Endoknife with a Water-Jet Function (Flushknife Proves Its Merits in Colorectal Endoscopic Submucosal Dissection Especially for the Cases Which Should Be Removed En Bloc

    Directory of Open Access Journals (Sweden)

    Yoji Takeuchi

    2013-01-01

    Full Text Available Background. Previously, we reported that the Flushknife (electrosurgical endoknife with a water-jet function could reduce the operation time of colorectal endoscopic submucosal dissection (ESD however, suitable situation for the Flushknife was obscure. This subgroup analysis of a prospective randomized controlled trial was aimed to investigate the suitable situation for the Flushknife. Methods. A total of 48 superficial colorectal neoplasms that underwent ESD using either the Flexknife or the Flushknife in a referral center were enrolled. The differences of operation time between the Flexknife and the Flushknife groups in each subgroup (tumor size, location, and macroscopic type were analyzed. Results. Median (95% CI operation time calculated using survival curves was significantly shorter in the Flushknife group than in the Flexknife group (55.5 min [41, 78] versus 74.0 [57, 90] min; , Hazard Ratio HR: 0.53; 95% CI (0.29–0.97. In particular, the HR in patients with laterally spreading tumors-nongranular type (LST-NG in the Flushknife group was significantly smaller than in the Flexknife group (HR: 0.1650.17; 95% CI (0.04–0.66. There was a trend of decreasing HRs according to larger lesion size. Conclusions. The Flushknife proved its merits in colorectal ESD especially for the lesions which should be removed en bloc (LST-NG and large lesion.

  3. 环空流体吸入式自激振荡脉冲射流大涡模拟研究%Large eddy simulation of self-oscillation pulsed water jet drawing in annulus fluid

    Institute of Scientific and Technical Information of China (English)

    杜玉昆; 王瑞和; 倪红坚

    2009-01-01

    发展新型破岩钻井技术对于促进油气田高效开发具有重要意义,高压水射流是提高破岩钻井效率的一个重要手段,脉冲射流是一种高效射流形式.为了充分利用井底水力能量,提出了一种环空流体吸入式脉冲射流的技术构想.基于自激振荡原理设计了相应射流调制工具,并对工具的流场和动力学特性进行了大涡模拟研究.研究结果分析揭示了环空流体吸入式自激振荡脉冲射流调制的机理,并发现合理的水力结构可以在振荡腔内实现局部负压,使得环空流体被吸入,参与调制生成高效脉冲射流.与非吸入式脉冲射流相比,吸入式脉冲射流振荡更加剧烈,破岩能力更强.研究结果得到了实验验证,为实际钻井工具的研制和相关工艺技术的开发提供了依据.%It is of great significance that developing new rock breaking drilling technology to promote efficient exploit of oil field. High pressure water jet drilling technology is an important method to promote the rock breaking drilling efficiency, and pulsed water jet is such a kind of high efficiency water jet. In order to take full advantage of hydraulic energy in bottom hole, a concept of new type of pulsed water jet drawing in annulus flow, is put forward. The pulsed water jet modulation tool is designed based on the self-exciting principle, and the large eddy simulation is adopted to simulate the flow field and the dynamic characteristics in this tool. This simulation shows the modulation mechanism of self-exciting pulsed water jet drawing in annulus flow. Partial negative pressure could be achieved in the oscillating cavity if the reasonable hydraulic structure is applied. The negative pressure formed in the drawing entrance of the oscillating cavity provides assurance to automatically draw enough fluid into annulus flow, which takes part in modulating the efficient pulsed water jet. The amplitude is larger and the rock breaking capacity of

  4. The Design and Research Long Throat Water Jet Air Ejector with Gland Steam Condenser%长喉部射水抽气器带轴封冷却器的设计与研究

    Institute of Scientific and Technical Information of China (English)

    廖奕奇

    2001-01-01

    This article analysis characteristic of long throat water jet airejector and gland sealing steam system. This ejector is the first success application used for 35 MW bleed steam and condenser type turbie. The drain water energy of the long throat jet air ejector used to the gland steam condenser. Make the gland sealing steam system simplified economic safety and reliable running.%分析了长喉部射水抽气器的工作特性和轴封系统的工作特性,首次在抽汽凝汽式35MW汽轮机中成功应用长喉部射水抽气器的排水余能带轴封冷却器,可使汽轮机的轴封系统简化、经济、安全可靠。

  5. STUDY ON JETS IMPACT IN AIR FOR ENERGY DISSIPATION

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    This paper is concerned with the applications of water jet impact in air to energy dissipation. The scattered jet flow impinges into the downstream water plunge pool, which greatly improves the inflow condition of the submerged jet in the pool and make it diffuse very quickly. The model experiments were conducted, which showed that a large jet flow could be scattered by a small one through impacting. The minimum discharge ratio for flow dispersion was studied. The unequal jet impact in air for energy dissipation was brought forward firstly in this paper as a new type of energy dissipator.

  6. Quadrantectomy for resection of spinal ependymomas with a new classification of unilateral approaches regarding bone drilling and the use of a new tool: The Balak ball-tipped water jet dissector

    Directory of Open Access Journals (Sweden)

    Naci Balak

    2016-09-01

    Conclusion: A quadrantectomy approach, which preserves the facet joints and midline structures, should be regarded as a safe subtype of unilateral approaches to spinal intradural lesions. This new terminology will be helpful in proper comparison of the results of various surgical approaches in terms of postoperative spinal instability. The ball-tipped water jet dissector is a beneficial tool for surgery in the cauda equina region.

  7. Analysis of the Internal and External Flow Fields of High Pressure Water Jet Nozzle in Radial Drilling%径向钻井高压水射流喷嘴内外流场分析

    Institute of Scientific and Technical Information of China (English)

    易松林; 汪志明; 孙怡红; 易先中; 吉源强; 刘利军

    2013-01-01

    The technology of high pressure water jet in radial drilling has currently been used widely at home and abroad. A numerical simulation and analysis of the internal and external flow fields of jet nozzle will lay the foundation for the further study of selection of rational nozzle structure as well as for high pressure water jet rock breaking. According to the jet dynamic principle, the physical and mathematical models of axial - symmetrical submerged jet rock breaking with single nozzle were established. A numerical simulation of the internal and external flow fields of high pressure water jet nozzle in radial drilling was conducted with the Fluent software. The laws of the internal and external flow fields were analyzed in different jet distances and inlet flowrates. The analysis shows that there exist velocity attenuation, velocity retention in the cylindrical section and migration in the maximum speed. When the jet flow impacts into the radial hole bottom, the water cushion will occur on the bottomhole wall surface. This will produce a barrier to nozzle advance. Stagnation will arise in high pressure water jet for radial drilling. This will be unfavorable to the transportation of cuttings in the drilling process.%径向钻井高压水射流技术目前在国内外得到了广泛应用.对射流喷嘴内、外流场进行数值模拟分析将为选择合理的喷嘴结构以及为高压水射流破岩的进一步研究奠定基础.根据射流动力学原理,建立了单喷嘴轴对称淹没射流破岩的物理模型和数学模型,运用Fluent软件对径向钻井高压水射流喷嘴内、外流场进行了数值模拟,并分析了在不同喷距和入口流量下喷嘴内、外流场的规律.分析结果表明,射流轴线上存在速度衰减性、圆柱段速度保持性和最大速度偏移性;当射流冲击到径向井底后,在井底壁面上产生水垫,对喷头的推进产生阻碍作用;在径向钻井高压水射流中会产生滞止现象,

  8. Extragalactic jets with helical magnetic fields: relativistic MHD simulations

    CERN Document Server

    Keppens, R; van der Holst, B; Casse, F

    2008-01-01

    Extragalactic jets are inferred to harbor dynamically important, organized magnetic fields which presumably aid in the collimation of the relativistic jet flows. We here explore by means of grid-adaptive, high resolution numerical simulations the morphology of AGN jets pervaded by helical field and flow topologies. We concentrate on morphological features of the bow shock and the jet beam behind the Mach disk, for various jet Lorentz factors and magnetic field helicities. We investigate the influence of helical magnetic fields on jet beam propagation in overdense external medium. We use the AMRVAC code, employing a novel hybrid block-based AMR strategy, to compute ideal plasma dynamics in special relativity. The helicity of the beam magnetic field is effectively transported down the beam, with compression zones in between diagonal internal cross-shocks showing stronger toroidal field regions. In comparison with equivalent low-relativistic jets which get surrounded by cocoons with vortical backflows filled by ...

  9. NASA's Large-Eddy Simulation Research for Jet Noise Applications

    Science.gov (United States)

    DeBonis, James R.

    2009-01-01

    Research into large-eddy simulation (LES) for application to jet noise is described. The LES efforts include in-house code development and application at NASA Glenn along with NASA Research Announcement sponsored work at Stanford University and Florida State University. Details of the computational methods used and sample results for jet flows are provided.

  10. Research on Cutting Metal Flash Detonator by Pre-mixed Abrasive Water Jet%前混合磨料水射流切割金属火雷管研究

    Institute of Scientific and Technical Information of China (English)

    张沙; 龚烈航; 王稳华

    2011-01-01

    磨料水射流切割作业具有高能、冷态、点割、非接触等特点,在有防爆要求的危险场合下进行切割作业有独特的优势.分析磨料水射流切割雷管金属外壳的磨损机制,并分析磨料水射流切割雷管的安全性;运用前混合磨料水射流对工程中常见的金属火雷管进行冷切割实验,取得了预期的效果.%As abrasive water jet has characteristics of high-energy, cold, point-cutting and non-contact etc, it has unique advantage to cut under the dangerous occasion that has the requirement of anti-explosion. The wear mechanism of cutting related plastic material such as metal flash detonator shell was researched, the security of cutting metal flash detonator using pre-mixed abrasive water jet was discussed, the cutting experiments on metal flash detonator using pre-mixed abrasive water jet were carried out. Expected effect was got in the experiments.

  11. MODELS FOR CALCULATING CUTTING DEPTH OF CASING BY PREMIXING ABRASIVE WATER JET%前混式磨料水射流切割套管的深度计算模型

    Institute of Scientific and Technical Information of China (English)

    周卫东; 王瑞和; 杨永印; 步玉环; 曹砚峰

    2001-01-01

    The physical model and mathematical model of casing-cutting using premixing abrasive water jet are presented. Theoretical analysis and experimental results show that the casing-cutting depth using premixing water jet taking granite as abrasive is apparently bigger than that by using sand as abrasive, which indicates the close relation between the depth and the types of abrasive. The results of this research give a theoretical basis for the application of premixing abrasive water jet technology in underwell rasing-cutting.%基于能量原理,建立了前混式磨料水射流切割套管的物理模型和数学模型。理论分析和实验结果表明,前混式磨料水射流切割套管的深度与磨料的种类有密切的关系。采用石榴石作磨料,其切割深度明显大于采用石英砂时的切割深度。该研究结果为将前混式磨料水射流技术应用于井下套管切割提供了理论根据。

  12. Mechanism of bullet-to-streamer transition in water surface incident helium atmospheric pressure plasma jet (APPJ)

    Science.gov (United States)

    Yoon, Sung-Young; Kim, Gon-Ho; Kim, Su-Jeong; Bae, Byeongjun; Kim, Seong Bong; Ryu, Seungmin; Yoo, Suk Jae

    2016-09-01

    The mechanism of bullet to streamer transition of helium-APPJ bullet on the electrolyte surface was investigated. The APPJ was discharged in pin-to-ring DBD reactor system with helium gas by applying the ac-driven voltage at a frequency of 10 kHz. The water evaporation was controlled via saline temperature. The temporal- and 2-dimensional spatially- resolved plasma properties are monitored by optical diagnostics. During the APPJ bullet propagation from reactor to electrolyte surface, the transition of bullet from streamer was recognized from the high speed image, hydrogen beta emission line, and bullet propagation speed. The He metastable species density profiles from the tunable diode laser absorption spectroscopy (TDLAS) showed the metastable lost the energy near electrolyte surface. It is found that the bullet transited to streamer when the water fraction reached to 29%. This can be fascinating result to study the plasma physics liquid surface, non-fixed boundary. Acknowledgements: This work was partly supported by R&D Program of `Plasma Advanced Technology for Agriculture and Food (Plasma Farming)' through the National Fusion Research Institute of Korea (NFRI) funded by the Government fund was carried out as part.

  13. Hydro-Jet technology in urologic surgery.

    Science.gov (United States)

    Shekarriz, Bijan

    2005-05-01

    Hydro-Jet technology utilizes an extremely thin, high-pressure stream of water. This technology has been routinely used in industry as a cutting tool for different materials such as metal, ceramic, wood and glass. Recently, Hydro-Jet technology has been used for dissection and resection during open and laparoscopic surgical procedures. A high-pressure jet of water allows selective dissection and isolation of vital structures such as blood vessels and nerves. This has resulted in improved dissection and decreased complication rate in recent experimental and clinical studies. This technology has been successfully applied during open and laparoscopic partial nephrectomy, cholecystecomy and retroperitoneal lymphadenectomy.

  14. The Giant Jet

    Science.gov (United States)

    Neubert, T.; Chanrion, O.; Arnone, E.; Zanotti, F.; Cummer, S.; Li, J.; Füllekrug, M.; van der Velde, O.

    2012-04-01

    Thunderstorm clouds may discharge directly to the ionosphere in spectacular luminous jets - the longest electric discharges on our planet. The electric properties of jets, such as their polarity, conductivity, and currents, have been predicted by models, but are poorly characterized by measurements. Here we present an analysis of the first gigantic jet that with certainty has a positive polarity. The jet region in the mesosphere was illuminated by an unusual sprite discharge generated by a positive cloud-to-ground lightning flash shortly after the onset of the jet. The sprite appeared with elements in a ring at ~40 km distance around the jet, the elements pointing curving away from the jet. This suggests that the field close the jet partially cancels the field driving the sprite. From a simple model of the event we conclude that a substantial portion of the positive cloud potential must be carried to ~50 km altitude, which is also consistent with the observed channel expansion and the electromagnetic radiation associated with the jet. It is further shown that blue jets are likely to substantially modify the free electron content in the lower ionosphere because of increased electron attachment driven by the jet electric field. The model further makes clear the relationship between jets, gigantic jets, and sprites. This is the first time that sprites are used for sounding the properties of the mesosphere. The observations presented here will allow evaluation of theories for jet and gigantic jet generation and of their influence on the atmosphere-ionosphere system.

  15. Analysis of ex-vessel melt jet breakup and coolability. Part 2: Uncertainty analysis

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, Kiyofumi; Park, Hyun Sun, E-mail: hejsunny@postech.ac.kr; Hwang, Byoungcheol; Jung, Woo Hyun

    2016-06-15

    Highlights: • Uncertainty analysis for quasi steady state melt jet breakup/cooling in APR1400. • Debris solidification reached in most of cases, film boiling quench never reached. • More than 1% molten pool formation in more than half probability. • Significant importance of accident conditions, weak impacts of model parameters. • Ratio of water depth to melt jet breakup length dominates the molten pool formation. - Abstract: An uncertainty analysis was performed on the molten core jet breakup and cooling by assuming the ex-vessel condition in APR1400, a Korean advanced pressurized water reactor, by probabilistic framework with the Latin Hypercube Sampling (LHS) and a fuel–coolant interaction (FCI) simulation code, JASMINE, as a physics model. Eight input variables including four model parameters and four initial/boundary condition variables were chosen as uncertainty variables. Three sets of size 100 samples, in total 300 cases of inputs were produced and simulation results were obtained for each of them. Statistics of the output variables as coolability indexes: the ratio of removed heat to the enthalpy for quench and the fraction of molten pool on the floor, indicated that, in the assumed range of conditions, the debris bed is likely to be cooled in average to the solidification point by ∼85% probability; however, it is not cooled to the minimum film boiling temperature, ∼500 K; and, more than 1% of the melt mass is in a molten pool on the floor by ∼65% probability. The importance analysis showed that the ratio of water pool depth and the melt jet breakup length dominates the cooling performance during the melt discharge transient. The uncertainty of initial and boundary condition variables such as the melt jet size and water pool depth is much more important than that of the model parameters.

  16. 250 MP a超高压磨料射流井下内切割技术∗%Downhole Inner Cutting Technology Based on 250 MPa Ultra High Pressure Abrasive Water Jet

    Institute of Scientific and Technical Information of China (English)

    马认琦; 李刚; 王超; 鞠少栋; 刘占鏖; 徐鸿飞

    2015-01-01

    The decommission of offshore oil and gas production facilities is in demand of high efficient, safe and environmentally friendly cutting technology and equipment�High pressure abrasive water jet cutting technology have obvious advantages on offshore well abandonment�The status of the application and development of domestic and foreign abrasive water jet cutting technology in offshore oil and gas production facilities decommission are de⁃scribed�Comparative analyses are conducted on the domestic and foreign downhole abrasive water jet cutting equip⁃ment and performance parameters�The core technologies and equipment of the existing domestic low pressure and 250 MPa ultra⁃high pressure abrasive water jet downhole inner cutting technology are introduced�Field application results showed that the low⁃pressure and 250 MPa ultra⁃high pressure abrasive water jet inner cutting technology and equipment could meet the operation requirements.%海上油气生产设施弃置需要配置高效、安全环保的切割处理技术及设备,高压磨料射流井下切割技术用于海上弃井作业优势明显。阐述了国内外磨料射流切割技术在海洋油气生产设施弃置领域的应用与发展现状,对比分析了国内外磨料射流井下切割设备及其性能参数,介绍了国内现有低压与250 MP a超高压磨料射流井下内切割核心技术及配套设备。现场应用结果表明,低压与超高压250 MP a磨料射流井下内切割技术及设备满足作业要求。

  17. Failure Mechanism of the Material Cut by High-pressure Abrasive Water Jet%高压磨料水射流切割中材料破坏机理的分析

    Institute of Scientific and Technical Information of China (English)

    王海宇; 王育立; 康灿

    2012-01-01

    As a kind of cold cutting technology, high-pressure water jet cutting has dlstmcnve advantages over other processing methods. Analysis of failure mode of the material cut by high-pressure abrasive water jet (AWJ) machine and observation under scanning electron microscope (SEM) were carried out. It indicates that there are two types of failure modes generated by AWJ, plastic failure and brittle failure and the surface quality of brittle failure is superior to that of plastic damage area. Analysis of failure mechanism of water jet shows that surface hardening of water jet induces the brittle failure in the initial period and the layer flake morphology which is relatively smooth. When the water jet gets diffused and the energy involved is insufficient to realize surface hardening, the grinding and ploughing function of abrasive roughen the surface.%高压水射流切割是一种冷态切割技术,相比其他加工方式具有其独到的优势。对高压水射流切割试样的实验研究,用扫描电镜对切割断面进行观测,分析了高压水射流对材料的破坏方式。研究表明,射流对固体材料的破坏方式主要有两种:塑性破坏和脆性破坏,脆性破坏区的表面质量优于塑性破坏区。对水射流的破坏机理分析表明,射流对表层金属的硬化作用,导致了在起始阶段内,材料呈现脆性破坏,电镜扫描图上呈现层片状剥离的形貌,切割面相对光滑。在射流能量耗散之后,不足以实现表层硬化,磨料的磨削"、犁耕"使断面粗糙度上升。

  18. Low-pressure water jet and laser composite cutting on Al2O3 ceramic%低压水射流激光复合切割Al2O3陶瓷的研究

    Institute of Scientific and Technical Information of China (English)

    陈春映; 袁根福; 王金华

    2014-01-01

    针对激光切割Al2O3陶瓷存在热裂纹、大量熔渣等问题,提出了低压水射流激光复合切割陶瓷技术,并将这种工艺与普通激光切割进行了对比,结果表明低压水射流激光复合切割陶瓷可以大大减少陶瓷切缝的熔渣、避免热裂纹。主要研究了辅助气体压力、激光脉冲能量和激光重复频率对水射流激光复合切割Al2O3陶瓷质量的影响规律,发现水射流存在时,辅助气体压力主要起到吹除切割头处水珠的作用,激光脉冲能量或激光重复频率增大、烧蚀材料增多,当烧蚀材料不能及时被射流冲除就形成了熔渣的累积,影响陶瓷切割质量。%As the thermal cracks, a large amount of slag etc. exist with laser cutting on Al2O3 ceramic, a technology called low-pressure water jet and laser composite cutting on ceramics was introduced. Compared with ordinary laser cutting, the results show that low-pressure water jet and laser cutting is better, which can greatly reduce the slag and avoid thermal cracks. The influence rules of low-pressure water jet and laser composite cutting on ceramics the different auxiliary gas pressure, laser pulse energy and repeated frequency on were mainly discussed, and found out that under the water jet, the auxiliary gas pressure mainly played the role in blowing the drops away from the cutting head. When the laser pulse energy or the repeated frequency increased, the ablation of the material increased, but if the material cannot take away by the water jet, that would be accumulated to large amount of slag which will impact the quality of ceramic cutting.

  19. 水射流—机械刀具联合破岩的影响因素试验研究%Experimental Research of Influence Factors on Combined Breaking Rock with Water Jet and Mechanical Tool

    Institute of Scientific and Technical Information of China (English)

    江红祥; 杜长龙; 刘送永; 许瑞

    2013-01-01

    为提高机械刀具破岩效率,在水射流—机械刀具联合破岩试验台上研究了水射流参数(射流入射角、喷嘴位置、靶距等)对联合破岩效果的影响.试验结果表明:喷嘴位置在刀具前方时,形成的煤岩碎片块度大,刀具的切削比能耗小,联合破岩效果优于喷嘴布置在刀具的两侧的破岩效果;刀具的切削比能耗与水射流入射角、靶距以及喷嘴和刀具距离的关系均呈抛物线变化,水射流入射角为120°、靶距为喷嘴直径5.5倍左右、喷嘴和刀具距离为切削深度的1.6倍左右时切削比能耗最低.%In order to enhance rock breaking effect of mechanical tool,the influences of water jet parameters(incident angle of water jet,nozzle position,butt distance,etc) on combined breaking rock effect were investigated on the test bed for combined breaking rock with water jet and mechanical tool. The results show that combined breaking rock effect(big rock fragments and low specific energy consumption of mechanical tool) is better when the nozzle on tool position ahead than on tool sides. The relationships among specific energy consumption of mechanical tool with incident angle of water jet,butt distance and the distance between nozzle and tool all have parabolic changes,and the specific energy consumption will be lowest when incident angle of water jet is 120°,butt distance is about 5. 5 times of nozzle diameter,distance between nozzle and tool is about 1. 6 times of depth of cut.

  20. 3D Modelling of a Vectored Water Jet-Based Multi-Propeller Propulsion System for a Spherical Underwater Robot

    Directory of Open Access Journals (Sweden)

    Xichuan Lin

    2013-01-01

    Full Text Available This paper presents an improved modelling method for a water jet‐based multi‐propeller propulsion system. In our previous work, the modelling experiments were only carried out in 2D planes, whose experimental results had poor agreement when we wanted to control the propulsive forces in 3D space directly. This research extends the 2D modelling described in the authors’ previous work into 3D space. By doing this, the model could include 3D space information, which is more useful than that of 2D space. The effective propulsive forces and moments in 3D space can be obtained directly by synthesizing the propulsive vectors of propellers. For this purpose, a novel experimental mechanism was developed to achieve the proposed 3D modelling. This mechanism was designed with the mass distribution centred for the robot. By installing a six‐axis load‐cell sensor at the equivalent mass centre, we obtained the direct propulsive effect of the system for the robot. Also, in this paper, the orientation surface and propulsive surfaces are developed to provide the 3D information of the propulsive system. Experiments for each propeller were first carried out to establish the models. Then, further experiments were carried out with all of the propellers working together to validate the models. Finally, we compared the various experimental results with the simulation data. The utility of this modelling method is discussed at length.