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Sample records for hydraulic jet catapult

  1. An Experimental Investigation of Hydraulic Jet Fracturing Technology with Coiled Tubing

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    To solve the increasingly serious problem of "many wells, but low productivity" in China, the hydraulic jetting fracturing technology with coiled tubing, as a new measure for effectively improving the production rate of individual well and enhancing oil and gas recovery, merits much attention nowa- days. On the basis of study of the hydraulic jetting fracturing mechanism with coiled tubing and numerical simulation of pressure distribution inside the pores, the mechanism of pressure rise inside the pores caused by the pressure boost action within the jetting pore and the hydraulic isolation action is examined, and the influence of main parameters on the pressure distribution inside the pores is analyzed. 3 kinds of operating methods of hydraulic jetting fracturing with coiled tubing are raised with the tubular diameter of coiled tub- ing as an important feature parameter. According to the experimental study, the fracturing mechanism and computational resuks of numerical simulation are both examined. It is considered that under the same pres- sure drop of jet nozzle, the pressure inside the pores increases with the confining pressure nearly at a line- ar state. When the vertical depth of the borehole is rather big and the rupture pressure of the formation is higher, it is recommended to use higher pressure drop of jet nozzle for achieving better pressure boost and hydraulic isolation effect. For the hydraulic jetting fracturing with coiled tubing, the coiled tubing with tu- bular diameter not less than 50. 8 mm (2 in. ) is usually used.

  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. 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.

  4. Combined Thermo-Hydraulic Analysis of a Cryogenic Jet

    CERN Document Server

    Chorowski, M

    1999-01-01

    A cryogenic jet is a phenomenon encountered in different fields like some technological processes and cryosurgery. It may also be a result of cryogenic equipment rupture or a cryogen discharge from the cryostats following resistive transition in superconducting magnets. Heat exchange between a cold jet and a warm steel element (e.g. a buffer tank wall or a transfer line vacuum vessel wall) may result in an excessive localisation of thermal strains and stresses. The objective of the analysis is to get a combined (analytical and experimental) one-dimensional model of a cryogenic jet that will enable estimation of heat transfer intensity between the jet and steel plate with a suitable accuracy for engineering applications. The jet diameter can only be determined experimentally. The mean velocity profile can be calculated from the fact that the total flux of momentum along the jet axis is conserved. The proposed model allows deriving the jet crown area with respect to the distance from the vent and the mean veloc...

  5. 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.

  6. Feeding kinematics, suction, and hydraulic jetting performance of harbor seals (Phoca vitulina).

    Science.gov (United States)

    Marshall, Christopher D; Wieskotten, Sven; Hanke, Wolf; Hanke, Frederike D; Marsh, Alyssa; Kot, Brian; Dehnhardt, Guido

    2014-01-01

    The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina) were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; Pfeeding events (0.18±0.08 s). Subjects feeding in-water used both a suction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events) compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land). Suction was characterized by a significantly smaller gape (1.3±0.23 cm; Pforce recorded was 53.9 kPa. Suction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their opportunistic, generalized feeding ecology and concomitant breadth of diet.

  7. Feeding Kinematics, Suction, and Hydraulic Jetting Performance of Harbor Seals (Phoca vitulina)

    Science.gov (United States)

    Marshall, Christopher D.; Wieskotten, Sven; Hanke, Wolf; Hanke, Frederike D.; Marsh, Alyssa; Kot, Brian; Dehnhardt, Guido

    2014-01-01

    The feeding kinematics, suction and hydraulic jetting capabilities of captive harbor seals (Phoca vitulina) were characterized during controlled feeding trials. Feeding trials were conducted using a feeding apparatus that allowed a choice between biting and suction, but also presented food that could be ingested only by suction. Subambient pressure exerted during suction feeding behaviors was directly measured using pressure transducers. The mean feeding cycle duration for suction-feeding events was significantly shorter (0.15±0.09 s; Psuction and a biting feeding mode. Suction was the favored feeding mode (84% of all feeding events) compared to biting, but biting comprised 16% of feeding events. In addition, seals occasionally alternated suction with hydraulic jetting, or used hydraulic jetting independently, to remove fish from the apparatus. Suction and biting feeding modes were kinematically distinct regardless of feeding location (in-water vs. on-land). Suction was characterized by a significantly smaller gape (1.3±0.23 cm; PSuction and hydraulic jetting where employed 90.5% and 9.5%, respectively, during underwater feeding events. Harbor seals displayed a wide repertoire of behaviorally flexible feeding strategies to ingest fish from the feeding apparatus. Such flexibility of feeding strategies and biomechanics likely forms the basis of their opportunistic, generalized feeding ecology and concomitant breadth of diet. PMID:24475170

  8. Thermal-hydraulic performance of convective boiling jet array impingement

    Science.gov (United States)

    Jenkins, R.; De Brún, C.; Kempers, R.; Lupoi, R.; Robinson, A. J.

    2016-09-01

    Jet impingement boiling is investigated with regard to heat transfer and pressure drop performance using a novel laser sintered 3D printed jet impingement manifold design. Water was the working fluid at atmospheric pressure with inlet subcooling of 7oC. The convective boiling performance of the impinging jet system was investigated for a flat copper target surface for 2700≤Re≤5400. The results indicate that the heat transfer performance of the impinging jet is independent of Reynolds number for fully developed boiling. Also, the investigation of nozzle to plate spacing shows that low spacing delays the onset of nucleate boiling causing a superheat overshoot that is not observed with larger gaps. However, no sensitivity to the gap spacing was measured once boiling was fully developed. The assessment of the pressure drop performance showed that the design effectively transfers heat with low pumping power requirements. In particular, owing to the insensitivity of the heat transfer to flow rate during fully developed boiling, the coefficient of performance of jet impingement boiling in the fully developed boiling regime deteriorates with increased flow rate due to the increase in pumping power flux.

  9. 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.

  10. Bow and catapult internal dynamics

    CERN Document Server

    Denny, M

    2003-01-01

    A simple model of bow and arrow dynamics is presented, which makes clear the physical principles, and reproduces the features obtained via more detailed, but less accessible calculations. We apply this instructive model to determine the efficiency of bows and of torsion-spring catapults.

  11. Bow and catapult internal dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Denny, Mark [4665 Amblewood Drive, Victoria, BC V8Y 1C1 (Canada)

    2003-07-01

    A simple model of bow and arrow dynamics is presented, which makes clear the physical principles, and reproduces the features obtained via more detailed, but less accessible calculations. We apply this instructive model to determine the efficiency of bows and of torsion-spring catapults.

  12. Hydraulic fluids and jet engine oil: pyrolysis and aircraft air quality.

    Science.gov (United States)

    van Netten, C; Leung, V

    2001-01-01

    Incidents of smoke in aircraft cabins often result from jet engine oil and/or hydraulic fluid that leaks into ventilation air, which can be subjected to temperatures that exceed 500 degrees C. Exposed flight-crew members have reported symptoms, including dizziness, nausea, disorientation, blurred vision, and tingling in the legs and arms. In this study, the authors investigated pyrolysis products of one jet engine oil and two hydraulic fluids at 525 degrees C. Engine oil was an important source of carbon monoxide. Volatile agents and organophosphate constituents were released from all the agents tested; however, the neurotoxin trimethyl propane phosphate was not found. The authors hypothesized that localized condensation of pyrolysis products in ventilation ducts, followed by mobilization when cabin heat demand was high, accounted for mid-flight incidents. The authors recommended that carbon monoxide data be logged continuously to capture levels during future incidents.

  13. The new Drop Tower catapult system

    Science.gov (United States)

    von Kampen, Peter; Kaczmarczik, Ulrich; Rath, Hans J.

    2006-07-01

    The Center of Applied Space Technology and Microgravity (ZARM) was founded in 1985 as an institute of the University Bremen, which focuses on research on gravitational and space-related phenomena. In 1988, the construction of the "Drop Tower" began. Since then, the eye-catching tower with a height of 146 m and its characteristic glass roof has become the emblem of the technology centre in Bremen. The Drop Tower Bremen provides a facility for experiments under conditions of weightlessness. Items are considered weightless, when they are in "free fall", i.e. moving without propulsion within the gravity field of the earth. The height of the tower limits the simple "free fall" experiment period to max. 4.74 s. With the inauguration of the catapult system in December 2004, the ZARM is entering a new dimension. This world novelty will meet scientists' demands of extending the experiment period up to 9.5 s. Since turning the first sod on May 3rd, 1988, the later installation of the catapult system has been taken into account by building the necessary chamber under the tower. The catapult system is located in a chamber 10 m below the base of the tower. This chamber is almost completely occupied by 12 huge pressure tanks. These tanks are placed around the elongation of the vacuum chamber of the drop tube. In its centre there is the pneumatic piston that accelerates the drop capsule by the pressure difference between the vacuum inside the drop tube and the pressure inside the tanks. The acceleration level is adjusted by means of a servo hydraulic breaking system controlling the piston velocity. After only a quarter of a second the drop capsule achieves its lift-off speed of 175 km/h. With this exact speed, the capsule will rise up to the top of the tower and afterwards fall down again into the deceleration unit which has been moved under the drop tube in the meantime. The scientific advantages of the doubled experiment time are obvious: during almost 10 s of high

  14. Hydraulics.

    Science.gov (United States)

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  15. Perspectives on Greek and Roman catapults

    Directory of Open Access Journals (Sweden)

    Mark Hassall

    1998-11-01

    Full Text Available Both the Greeks and the Romans showed great ingenuity in developing catapults as artillery weapons. Evidence of how these complicated machines worked comes from surviving descriptions, experimental reconstructions and archaeological remains. Ancient technical drawings are a valuable but relatively neglected source of information about catapult design, and one that poses challenging problems of interpretation.

  16. Vortices catapult droplets in atomization

    Science.gov (United States)

    Jerome, J. John Soundar; Marty, Sylvain; Matas, Jean-Philippe; Zaleski, Stéphane; Hoepffner, Jérôme

    2013-11-01

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vortex; this reattached flow pushes the liquid film down; by now, a new recirculation vortex is being created in the wake of the wave—just where the liquid film is now located; the liquid film is blown up from below by the newly formed recirculation vortex in a manner similar to a bag-breakup event; the resulting droplets are catapulted by the recirculation vortex.

  17. Vortices catapult droplets in atomization

    Energy Technology Data Exchange (ETDEWEB)

    Jerome, J. John Soundar, E-mail: soundar@dalembert.upmc.fr; Zaleski, Stéphane; Hoepffner, Jérôme [Institut Jean Le Rond d' Alembert, UPMC Univ. Paris 06 and CNRS-UMR 7190, F-75005 Paris (France); Marty, Sylvain; Matas, Jean-Philippe [Laboratoire des Écoulements Géophysiques et Industriels (LEGI), Univ. Grenoble Alpes and CNRS - UMR 5519, F-38000 Grenoble (France)

    2013-11-15

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vortex; this reattached flow pushes the liquid film down; by now, a new recirculation vortex is being created in the wake of the wave—just where the liquid film is now located; the liquid film is blown up from below by the newly formed recirculation vortex in a manner similar to a bag-breakup event; the resulting droplets are catapulted by the recirculation vortex.

  18. The fern sporangium: a unique catapult.

    Science.gov (United States)

    Noblin, X; Rojas, N O; Westbrook, J; Llorens, C; Argentina, M; Dumais, J

    2012-03-16

    Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of human-made catapults with one notable exception: The sporangia lack the crossbar that arrests the catapult arm in its returning motion. We show that much of the sophistication and efficiency of the ejection mechanism lies in the two very different time scales associated with the annulus closure.

  19. Catapulting tentacles in a sticky carnivorous plant.

    Directory of Open Access Journals (Sweden)

    Simon Poppinga

    Full Text Available Among trapping mechanisms in carnivorous plants, those termed 'active' have especially fascinated scientists since Charles Darwin's early works because trap movements are involved. Fast snap-trapping and suction of prey are two of the most spectacular examples for how these plants actively catch animals, mainly arthropods, for a substantial nutrient supply. We show that Drosera glanduligera, a sundew from southern Australia, features a sophisticated catapult mechanism: Prey animals walking near the edge of the sundew trigger a touch-sensitive snap-tentacle, which swiftly catapults them onto adjacent sticky glue-tentacles; the insects are then slowly drawn within the concave trap leaf by sticky tentacles. This is the first detailed documentation and analysis of such catapult-flypaper traps in action and highlights a unique and surprisingly complex mechanical adaptation to carnivory.

  20. Catapulting tentacles in a sticky carnivorous plant.

    Science.gov (United States)

    Poppinga, Simon; Hartmeyer, Siegfried Richard Heinrich; Seidel, Robin; Masselter, Tom; Hartmeyer, Irmgard; Speck, Thomas

    2012-01-01

    Among trapping mechanisms in carnivorous plants, those termed 'active' have especially fascinated scientists since Charles Darwin's early works because trap movements are involved. Fast snap-trapping and suction of prey are two of the most spectacular examples for how these plants actively catch animals, mainly arthropods, for a substantial nutrient supply. We show that Drosera glanduligera, a sundew from southern Australia, features a sophisticated catapult mechanism: Prey animals walking near the edge of the sundew trigger a touch-sensitive snap-tentacle, which swiftly catapults them onto adjacent sticky glue-tentacles; the insects are then slowly drawn within the concave trap leaf by sticky tentacles. This is the first detailed documentation and analysis of such catapult-flypaper traps in action and highlights a unique and surprisingly complex mechanical adaptation to carnivory.

  1. 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.

  2. The fern sporangium: an ultrafast natural catapult

    Science.gov (United States)

    Noblin, Xavier; Argentina, Mederic; Westbrook, Jared; Llorens, Coraline; Rojas, Nicolas; Dumais, Jacques

    2012-02-01

    Plants have developed fascinating mechanisms to create ultra fast movements that often reach the upper limit allowed by physical laws. Inspiration for new technologies is one of the reasons for the strong interest for these mechanisms, along with the deep interest of understanding complex, natural systems. The fern sporangium is a capsule that contains the spores, it is surrounded by a row of cells called the annulus which acts as a beam. Due to the water evaporation from its cells, the annulus bends strongly and induces elastic energy storage during an opening phase. The tension in the cells breaks when cavitation bubbles appear in the cells, leading to a fast release of the elastic energy. The fern sporangium then acts as a catapult which ejects rapidly its spores by closing back to the initial closed shape. We have analyzed the slow opening motion and the fast catapulting mechanism. We found that the catapult motion involves two time scales, showing a very original behavior. In man-made catapults, the recoil motion needs to be arrested by a cross bar so that the projectile is released from the arm. We show here that the fern sporangium replaces the essential cross bar by an elegant poroelastic damping, leading to a completely autonomous, efficient device.

  3. Analogy Between Hydraulic Jump in Films Formed by Impinging Liquid Jet and Critical Flow in Internal Flows

    Institute of Scientific and Technical Information of China (English)

    Jaroslaw Mikielewicz

    2003-01-01

    Formulated are simple models for the flow in liquid film, formed by impinging jet, and a two-phase downward flow in pipe. The models are based on simplified equations of mass, momentum and energy. The solutions of such conservation equations may have regular points belonging to one integral curve only as well as turning points can be found amongst them, which refer to extreme values in the appropriate co-ordinate system. The solutions can also have singular points belonging to none or more than one integral curve. Both the turning and singular points have a clear physical meaning. They could be linked to critical flow conditions in the pipe flow or to the so-called hydraulic jump. Analogy existing between critical conditions in the pipe and the flow of liquid films formed by the liquid jet have been shown in the paper.

  4. The fern sporangium: a unique catapult.

    OpenAIRE

    Noblin, X.; Rojas, N. O.; Westbrook, J; Llorens, C.; Argentina, M.; Dumais, J.

    2012-01-01

    International audience; Various plants and fungi have evolved ingenious devices to disperse their spores. One such mechanism is the cavitation-triggered catapult of fern sporangia. The spherical sporangia enclosing the spores are equipped with a row of 12 to 13 specialized cells, the annulus. When dehydrating, these cells induce a dramatic change of curvature in the sporangium, which is released abruptly after the cavitation of the annulus cells. The entire ejection process is reminiscent of ...

  5. Operation history of hydraulic jet pump on teh Chengbei oil field, China. Chengbei yuden ni okeru haidororikku jet pump no shiyo jisseki

    Energy Technology Data Exchange (ETDEWEB)

    Terao, Yoshihiro; Takagi, Sunao

    1989-11-01

    Changbei oil field in China uses hydraulic jet pump(HJP) to cope with the increase of oil production and increase of water content in the oil field. This paper described the practical result. This pump makes high speed jet by driving fluid, and converts the dynamic energy to pressure energy by decelerating with a diffuser to push up oil. Wellheads damaged by sand friction or near the gas cap were removed. The production from March, 1988 to October increased at the rate of 114kl/day at total 8 wellheads. Heavy oil of API specific gravity of 16 degree could be proved. Since the separation of oil and water was inferior, so that the countermeasures were studied but the cause was not known. Troubles or failures of main body, nozzle and throat of HJP were not occurred. Any effect could not be found at a wellhead of water content exceeding 50 to 60% because only water production increased. Consequently, this process could result the increase of oil production with lower cost and without mechanical failures. 2 refs., 7 figs., 7 tabs.

  6. Botany: a record-breaking pollen catapult.

    Science.gov (United States)

    Edwards, Joan; Whitaker, Dwight; Klionsky, Sarah; Laskowski, Marta J

    2005-05-12

    The release of stored elastic energy often drives rapid movements in animal systems, and plant components employing this mechanism should be able to move with similar speed. Here we describe how the flower stamens of the bunchberry dogwood (Cornus canadensis) rely on this principle to catapult pollen into the air as the flower opens explosively. Our high-speed video observations show that the flower opens in less than 0.5 ms--to our knowledge, the fastest movement so far recorded in a plant.

  7. The cable catapult - Putting it there and keeping it there

    Science.gov (United States)

    Forward, Robert L.; Conley, Buford R.; Stanek, Clay; Ramsey, William

    1992-01-01

    The cable catapult is the previously proposed method of using long space tethers for high speed interplanetary transport. A long conductive multistrand cable would be connected to a power supply and pointed in the desired direction. A linear motor would pull itself along the powered cable strands and launch a payload capsule toward a distant planet, where it would be caught and decelerated by another cable catapult positioned there. In this paper it is shown how cable catapults can be used to transport themselves to a distant planet and keep themselves in position near the planet despite the tendency of the payload capsule momentum transfer to push them apart.

  8. Design of Dsppool Based on Catapult C%基于Catapult C的Dsppool设计

    Institute of Scientific and Technical Information of China (English)

    罗锋; 刘新宁

    2009-01-01

    在此使用高级语言进行运算加速模块Dsppool描述,再使用Mentor公司的Catapult C工具完成RTL设计,并为Dsppool模块进行满足APB接口的封装,使之能够作为一个AMBA总线上的Slave模块.实验结果显示,使用硬件描述语言手动设计的Dsppool模块与CatapultC设计的RTL代码功能完全一致,并且综合后性能相当,因为高级语言忽略了硬件设计中的细节,设计速度比直接使用硬件描述语言快几倍到几十倍.

  9. 'Catapult' offshore renewables into commercial use

    Energy Technology Data Exchange (ETDEWEB)

    Block, Elizabeth

    2012-07-01

    In February, the Technology Strategy Board, the UK's government innovation agency, appointed a consortium to set up the Offshore Renewable Energy Catapult centre, with Sterling Pounds 50 million to be spent over five years. (orig.)

  10. TC-13 Mod 0 and Mod 2 Steam Catapult Test Site

    Data.gov (United States)

    Federal Laboratory Consortium — Located on 11,000 feet of test runway, the TC-13 Mod 0 and Mod 2 Steam Catapult Test Site has in-ground catapults identical to those aboard carriers. This test site...

  11. Planetary-scale hydraulic jumps and transonic jet-streaks in the MACDA reanalysis of the Martian atmosphere: a comparison with Earth's lower mesosphere

    Science.gov (United States)

    Dowling, Timothy E.; Bradley, Mary Elizabeth; Lewis, Stephen R.; Read, Peter L.

    2016-10-01

    We have analyzed the Mars MACDA V1.0 global reanalysis on potential-temperature surfaces, θ, over the range θ = 400 to 900 K (~30 to ~60 km). The strongest seasonal wind, the northern-winter polar jet, exhibits two intriguing features: i) transonic jet streaks and ii) the juxtaposition of regions of shooting and tranquil flow, in the sense of Froude-number hydraulics, which suggests a planetary-scale hydraulic jump. Mesoscale bores have been studied on Mars, but to our knowledge the above two features have not been reported elsewhere. To characterize the basic state, we examine scatter plots of Ertel potential vorticity, Q, versus Bernoulli streamfunction, B, and fit the linear model Q/Q0 = 1 - μ0 (B-B0). In autumn, winter and spring, the nondimensionalized correlation parameter, μ'0 = (NH)2 μ0, in mid-latitudes is positive and nearly constant in time. Its value is close to unity at the bottom of the study region and gradually decreases with increasing θ (increasing altitude). In northern summer it swings negative. These attributes match Earth's lower mesosphere (θ = 2000 to 3000 K; ~48 to ~62 km). In southern summer, Ls ~ 270○, a hypsometric flaring of the θ layers, which is not seen in northern summer, is associated with the previously reported reduction of Q to approximately zero across the entire southern hemisphere and northern tropics. Between each winter polar jet and pole, especially in the north, there is a large spread of Q over a small domain of B, which is unlike Earth and may be related to the aforementioned hydraulic jump. We are currently examining 3D Lagrangian fluid trajectories to better characterize the rotating hydraulics of the system as a function of season.

  12. Outburst Prevention Technology with Borehole Hydraulic Jet Through Strata in Floor Gateway%底板巷穿层钻孔水力冲孔防突技术

    Institute of Scientific and Technical Information of China (English)

    刘明举; 郭献林; 李波; 王冕

    2011-01-01

    针对新安矿14211运输巷掘进过程中面临的煤与瓦斯突出问题,为了研究和确定适合新安煤田三软煤层赋存特点的水力冲孔工艺和消突评价体系,使其快速消除工作面突出危险性,提高煤巷掘进速度,采用底板巷穿层钻孔水力冲孔防突措施,按照考察出的冲孔影响半径均匀布置钻孔,排出部分煤体和瓦斯,使煤体卸压增透.试验结果表明,底板巷穿层水力冲孔技术较好地适应和利用了三软煤层的赋存特点,消除了工作面的突出危险性,掘进速度也由之前的40 m/月提高到75m/月,提高了87.5%.%According to coal and gas outburst problems occurred in the heading process of the No.14211 transportation gateway in Xin'an Mine, in order to study and set up the borehole hydraulic jet technique and the outburst evaluation system suitable for the three soft seam deposit features in Xin'an Coalfield, to rapidly eliminate the outburst danger of the heading face and to improve the seam gateway heading speed, the outburst prevention measures with borehole hydraulic jet through the strata in the floor gateway were applied.According the investigation of the borehole hydraulic jet influence radius, a layout of the berehole pattern was evenly set up and a partial coal and gas could be discharged.Thus the seam pressure could be released and the permeability of the seam could be improved.The experiment result showed that the borehole hydraulic jet technology passed through strata in the floor gateway would be well suitable for and utilization of the deposit features of the three soft seam and could eliminate the outburst danger of the heading face.Thus the heading speed could be improved from the previous 40 m/month to 75 m/month and the heading efficiency was improved by 87.5%.

  13. Construct-a-Catapult. Science by Design Series.

    Science.gov (United States)

    Pulis, Lee

    This book is one of four books in the Science-by-Design Series crated by TERC and funded by the National Science Foundation (NSF). It integrates history, physics, mathematics, and technology in its challenge to high school students to design and build a working catapult system. Students investigate elasticity, projectile launching, and learn about…

  14. Numerical Simulation of Working Parameters for Hydraulic Oscillator Jet%射流式水力振荡器工作参数数值模拟

    Institute of Scientific and Technical Information of China (English)

    那枫

    2016-01-01

    通过 CFD 数值模拟方法分析射流式水力振荡器内部复杂流场,尤其在射流式压力脉冲短节内部由射流元件、缸体、活塞、节流盘所组成的复杂流场的速度场、压力场变化情况。运用 Solid-works、Hypermesh、FLUENT 软件,建立合理模型,选择合理的数值计算方法,进行了射流式水力振荡器内部流场数值模拟研究,对优化该工具的结构设计具有指导性意义。%By CFD numerical simulation method,complex flow field inside the Jet hydrodynamic oscillators is analyzed,especially within the pressure pulse jet nipple by Jet components,cylin-ders,pistons,throttle plate consisting of complex flow field velocity,pressure changes.Using Solidworks,Hypermesh,FLUENT software are used to establish a rational model,reasonable se-lection of numerical methods and select reasonable numerical simulation to study jet flow field in hydraulic oscillator for optimization of structural design of the tool,which are of guiding signifi-cance.

  15. Thermo - hydraulic analysis of a cryogenic jet: application to helium recovery following resistive transitions in the LHC

    CERN Document Server

    Chorowski, M; Konopka, G

    1999-01-01

    A resistive transition (quench) of the LHC sector magnets will be followed by cold helium venting to a quench buffer volume of 2000 m3 at ambient temperature. The volume will be composed of eight medium-pressure (2 MPa) gas storage tanks made of carbon steel, which constrains the temperature of the wall to be higher than -50 oC (223 K). Possible spot cooling intensity and thermo-mechanical stresses in the tank wall following helium injection have been analysed previously and the aim of the present study is experimental verification of basic assumptions concerning cryogenic jet parameters and heat transfer between jet crown and tank wall. For this purpose jet diameter, velocity profile and convective heat transfer between jet and steel plate have been measured. A simple jet model description based on momentum conservation has been proposed. Then, the lowest possible temperature of the tank wall which may occur has been assessed.

  16. Concept of an induction-dynamic catapult for a ballistic laser gravimeter

    OpenAIRE

    Bolyukh, V.F.; Vinnichenko, A. I.

    2014-01-01

    A design is proposed for an inductive-dynamic catapult in a ballistic laser gravimeter with a fixed inductor and an electrically conducting armature that moves together with the test object along a vertical axis. The catapult ensures improved accuracy of the gravimeter through direct conversion of electrical into kinetic energy. The electrical circuit of the catapult provides two successive current pulses to the inductor for launching and braking of the armature during the operating cycle.

  17. Catapult launch-associated cardioversion of atrial fibrillation.

    Science.gov (United States)

    Bohnker, B K; Feeks, E F; McEwen, G

    1993-10-01

    A patient is presented with new-onset atrial fibrillation. While being air-evacuated, he cardioverted during the acceleration associated with aircraft carrier catapult launch. This case suggests a possible myocardial response to the kinetic energy produced by the acceleration force, similar to the electrical energy commonly used for cardioversion. Cardioversion using acceleration forces is probably not a clinically useful modality; however, this case demonstrates the importance of acceleration forces on patients during medical evacuation from aircraft carriers.

  18. 基于Catapult C的DCT算法设计

    Institute of Scientific and Technical Information of China (English)

    谢正; 张开锋

    2011-01-01

    以DCT(Discrete Cosine Transform)的实现为例,利用Catapult C探索不同的设计架构,快速设计出性能、面积和功耗之间折衷的最佳实现方案,并与传统的手工编写VHDL代码实现方式进行比较。

  19. 基于Catapult C的DCT算法设计%Design of DCT Algorithm Based on Catapult C

    Institute of Scientific and Technical Information of China (English)

    谢正; 张开锋

    2011-01-01

    以DCT( Discrete Cosine Transform)的实现为例,利用CatapultC探索不同的设计架构,快速设计出性能、面积和功耗之间折衷的最佳实现方案,并与传统的手工编写VHDL代码实现方式进行比较.

  20. Universities, Catapult Centres and the 2014 Hauser Review. Innovation and Growth Factsheet Series. No. 2

    Science.gov (United States)

    Universities UK, 2014

    2014-01-01

    This factsheet, the second in a series on innovation and growth, provides an overview of Catapult centres and how universities engage with them, with reference to the recommendations of the second Hauser review into the future of the Catapult network. The factsheet draws on a review of existing literature as well as the perspectives of businesses,…

  1. Analysis of the Design Criteria for Ancient Greek and Roman Catapults

    DEFF Research Database (Denmark)

    Paasch, Kasper

    2011-01-01

    This paper will give a short overview of use of COMSOL Multiphysics for analyzing ancient Greek and Roman catapults with the main focus on the energy storing torsion springs. Catapults have been known and used in the Greek and Roman world from around 399 BC and a fully standardized design...

  2. Universities, Catapult Centres and the 2014 Hauser Review. Innovation and Growth Factsheet Series. No. 2

    Science.gov (United States)

    Universities UK, 2014

    2014-01-01

    This factsheet, the second in a series on innovation and growth, provides an overview of Catapult centres and how universities engage with them, with reference to the recommendations of the second Hauser review into the future of the Catapult network. The factsheet draws on a review of existing literature as well as the perspectives of businesses,…

  3. A Catapult (Slingshot) Current Sheet Relaxation Model for Substorm Triggering

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.

    2010-12-01

    Based on the results of our superposed epoch analysis of Geotail data, we have proposed a catapult (slingshot) current sheet relaxation model in which earthward flows are produced in the central plasma sheet (CPS) due to the catapult (slingshot) current sheet relaxation, together with the rapid enhancement of Poynting flux toward the CPS in the lobe around X ~ -15 Re about 4 min before the substrom onset. These earthward flows are characterized by plasma pressure decrease and large amplitude magnetic field fluctuations. When these flows reach X ~ 12Re in the magnetotail, they give significant disturbances to the inner magnetosphere to initiate some instability such as a ballooning instability or other instabilities, and the substorm starts in the inner magnetosphere. The occurrence of the magnetic reconnection is a natural consequence of the initial convective earthward flows, because the relaxation of a highly stretched catapult current sheet produces a very thin current at its tailward edge being surrounded by intense magnetic fields which were formerly the off-equatorial lobe magnetic fields. Recently, Nishimura et al. [2010] reported that the substorm onset begins when faint poleward discrete arcs collide with equatorward quiet arcs. The region of earthward convective flows correlatively moves earthward prior to the onset. Thus, this region of the earthward convective flows seems to correspond to the faint poleward discrete arcs. Interestingly, our statistical analysis shows that the earthward convective flows are not produced by the magnetic reconnection, but they are attributed to the dominance of the earthward JxB force over the tailward pressure associated with the progress of the plasma sheet thinning.

  4. The fern cavitation catapult: mechanism and design principles.

    Science.gov (United States)

    Llorens, C; Argentina, M; Rojas, N; Westbrook, J; Dumais, J; Noblin, X

    2016-01-01

    Leptosporangiate ferns have evolved an ingenious cavitation catapult to disperse their spores. The mechanism relies almost entirely on the annulus, a row of 12-25 cells, which successively: (i) stores energy by evaporation of the cells' content, (ii) triggers the catapult by internal cavitation, and (iii) controls the time scales of energy release to ensure efficient spore ejection. The confluence of these three biomechanical functions within the confines of a single structure suggests a level of sophistication that goes beyond most man-made devices where specific structures or parts rarely serve more than one function. Here, we study in detail the three phases of spore ejection in the sporangia of the fern Polypodium aureum. For each of these phases, we have written the governing equations and measured the key parameters. For the opening of the sporangium, we show that the structural design of the annulus is particularly well suited to inducing bending deformations in response to osmotic volume changes. Moreover, the measured parameters for the osmoelastic design lead to a near-optimal speed of spore ejection (approx. 10 m s(-1)). Our analysis of the trigger mechanism by cavitation points to a critical cavitation pressure of approximately -100 ± 14 bar, a value that matches the most negative pressures recorded in the xylem of plants. Finally, using high-speed imaging, we elucidated the physics leading to the sharp separation of time scales (30 versus 5000 µs) in the closing dynamics. Our results highlight the importance of the precise tuning of the parameters without which the function of the leptosporangium as a catapult would be severely compromised.

  5. Multi-elemental analysis of jet engine lubricating oils and hydraulic fluids and their implication in aircraft air quality incidents.

    Science.gov (United States)

    van Netten, C

    1999-05-07

    The flight crews of aircraft often report symptoms including dizziness, nausea, disorientation, blurred vision and tingling in legs and arms. Many of these incidents have been traced to contamination of cabin air with lubricating oil, as well as hydraulic fluid, constituents. Considering that these air contaminants are often subjected to temperatures in excess of 500 degrees C, a large number of different exposures can be expected. Although the reported symptoms are most consistent with exposures to volatile organic compounds, carbon monoxide, and the organophosphate constituents in these oils and fluids, the involvement of these agents has not been clearly demonstrated. Possible exposure to toxic elements, such as lead, mercury, thallium and others, have not been ruled out. In order to assess the potential of exposure to toxic elements a multi-elemental analysis was done on two hydraulic fluids and three lubricating oils which have been implicated in a number of air quality incidents. A secondary objective was to establish if the multi-elemental concentrations of the fluids tested are different enough to allow such an analysis to be used as a possible method of identifying the source of exposure that might have been present during aircraft air quality incidents. No significant concentrations of toxic elements were identified in any of the oils or hydraulic fluids. The elemental compositions of the samples were different enough to be used for identification purposes and the measurement of only three elements was able to achieve this. Whether these findings have an application, in aircraft air quality incident investigations, needs to be established with further studies.

  6. Capillary-Inertial Colloidal Catapult upon Drop Coalescence

    Science.gov (United States)

    Chavez, Roger; Liu, Fangjie; Feng, James; Chen, Chuan-Hua

    2014-11-01

    To discharge micron-sized particles such as colloidal contaminants and biological spores, an enormous power density is needed to compete against the strong adhesive forces between the small particles and the supporting surface as well as the significant air friction exerted on the particles. Here, we demonstrate a colloidal catapult that achieves such a high power density by extracting surface energy released upon drop coalescence within an extremely short time period, which is governed by the capillary-inertial process converting the released surface energy into the bulk inertia of the merged drop. When two drops coalesce on top of a spherical particle, the resulting capillary-inertial oscillation is perturbed by the solid particle, giving rise to a net momentum eventually propelling the particle to launch from the supporting surface. The measured launching velocity follows a scaling law that accounts for the redistribution of the momentum of the merged drop onto the particle-drop complex, and is therefore proportional to the capillary-inertial velocity characterizing the coalescing drops. The interfacial flow process associated with the colloidal catapult is elucidated with both high-speed imaging and phase-field simulations.

  7. The Applications of Dry Jet Mixing in the Coastal Areas of Hydraulic Engineering%粉喷桩在沿海地区水利工程中的的应用

    Institute of Scientific and Technical Information of China (English)

    戴恩运

    2013-01-01

      在沿海地区水利工程中,水泥粉喷搅拌桩是地基与基础处理常用的一种方法。本文通过作者的工作实践,并结合工程实例对粉喷桩在沿海地区水利工程中的应用进行简单的阐述与分析。%In the coastal areas of hydraulic engineering, the c-ement powder jet mixing pile is a common method of the sub-grade and the basis of processing. In this article, the author ba-ses on the working practices, briefly elaborates and analysis th-e applications of Dry Jet Mixing in the coastal areas of hydrau-lic engineering.

  8. 舰载机不同弹射系统的弹射过程%Catapult Process of Different Catapult Systems for Carrier-Based Aircraft

    Institute of Scientific and Technical Information of China (English)

    甄子洋; 江驹; 王新华; 朱熠

    2012-01-01

    针对目前世界上最典型的两种舰载机弹射系统:蒸汽弹射系统和电磁弹射系统,对比研究了不同弹射系统的结构原理、数学模型、弹射性能等问题.分析了常用的蒸汽弹射装置和电磁装置的组成部件及其功用,给出对比分析结果;根据蒸汽弹射装置和电磁弹射装置的运动学特性,获得两种弹射装置的数学模型,推导出它们的非线性运动学方程,并给出对比分析结果;针对两种不同的弹射系统,构建了舰载机在舰面加速段的弹射过程的Matlab数值仿真模型,通过仿真研究,分析了不同弹射系统中对弹射性能起主要影响作用的关键因素,并根据仿真结果进行了对比分析.%The structure, principle, mathematical models and performance were studied for the two typical methods, steam catapult and Electromagnetic Aircraft Launch System ( EMALS) , for catapult launch of carrier-based aircraft. The compositions of steam catapult and EMALS were analyzed. The functions of the different parts of the catapult systems were also discussed. According to the kinematical characteristics of steam catapult and EMALS, the mathematical models were established, their nonlinear kinematical equations were deduced and the comparative analysis reslult was given. Simulations were made for the two catapult methods on the speeding stage of the aircraft. The main factors that have effect on catapult launch performance were analysed for different catapult methods by using the simulation result. Comparison of the two catapult launch systems was also made.

  9. Capillary-inertial colloidal catapults upon drop coalescence

    Science.gov (United States)

    Chavez, Roger L.; Liu, Fangjie; Feng, James J.; Chen, Chuan-Hua

    2016-07-01

    Surface energy released upon drop coalescence is known to power the self-propelled jumping of liquid droplets on superhydrophobic solid surfaces, and the jumping droplets can additionally carry colloidal payloads toward self-cleaning. Here, we show that drop coalescence on a spherical particle leads to self-propelled launching of the particle from virtually any solid surface. The main prerequisite is an intermediate wettability of the particle, such that the momentum from the capillary-inertial drop coalescence process can be transferred to the particle. By momentum conservation, the launching velocity of the particle-drop complex is proportional to the capillary-inertial velocity based on the drop radius and to the fraction of the liquid mass in the total mass. The capillary-inertial catapult is not only an alternative mechanism for removing colloidal contaminants, but also a useful model system for studying ballistospore launching.

  10. Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping

    OpenAIRE

    Astley, Henry C.; Roberts, Thomas J.

    2011-01-01

    Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplana...

  11. Principles of laser microdissection and catapulting of histologic specimens and live cells.

    Science.gov (United States)

    Vogel, Alfred; Horneffer, Verena; Lorenz, Kathrin; Linz, Norbert; Hüttmann, Gereon; Gebert, Andreas

    2007-01-01

    Rapid contact- and contamination-free procurement of specific samples of histologic material for proteomic and genomic analysis as well as separation and transport of living cells can be achieved by laser microdissection (LMD) of the sample of interest followed by a laser-induced forward transport process [laser pressure "catapulting," (LPC)] of the dissected material. We investigated the dynamics of LMD and LPC with focused and defocused laser pulses by means of time-resolved photography. The working mechanism of microdissection was found to be plasma-mediated ablation. Catapulting is driven by plasma formation, when tightly focused pulses are used, and by ablation at the bottom of the sample for moderate and strong defocusing. Driving pressures of several hundred megapascals accelerate the specimen to initial velocities of 100-300 m/s before it is rapidly slowed down by air friction. With strong defocusing, driving pressure and initial flight velocity decrease considerably. On the basis of a characterization of the thermal and optical properties of the histologic specimens and supporting materials used, we calculated the temporal evolution of the heat distribution in the sample. After laser microdissection and laser pressure catapulting (LMPC), the samples were inspected by scanning electron microscopy. Catapulting with tightly focused or strongly defocused pulses results in very little collateral damage, while slight defocusing involves significant heat and UV exposure of up to about 10% of the specimen volume, especially if samples are catapulted directly from a glass slide. Time-resolved photography of live-cell catapulting revealed that in defocused catapulting strong shear forces originate from the flow of the thin layer of culture medium covering the cells. By contrast, pulses focused at the periphery of the specimen cause a fast rotational movement that makes the specimen wind its way out of the culture medium, thereby undergoing much less shear stresses

  12. Biodynamic Assessment of Pilot Knee-Board Configurations During Simulated T-38 Catapult Acceleration

    Science.gov (United States)

    2015-04-01

    0041 Biodynamic Assessment of Pilot Knee -Board Configurations During Simulated T-38 Catapult Acceleration Mr. Chris Perry Mr. Chris...to April 2015 4. TITLE AND SUBTITLE Biodynamic Assessment of Pilot Knee -Board Configurations During Simulated T-38 Catapult Acceleration 5a...and converted to AVI format, and stored in the RH Collaborative Biomechanics Data Bank. Photographs were taken of the test set-up prior to each test

  13. Development of a New Specification for Aircraft Catapult Lubricant, LA7, NSN 9150-01-430-2884

    Science.gov (United States)

    2013-09-30

    DEVELOPMENT OF A NEW SPECIFICATION FOR AIRCRAFT CATAPULT LUBRICANT, LA7, NSN 9150-01-430-2884 NF&LCFT REPORT 441/13-009 30 September 2013...Page Table 1. Proposed Requirements For A Dedicated Mineral Oil Based Catapult Lubricant. ............. 21 LIST OF FIGURES Figure...September 2013 Page v EXECUTIVE SUMMARY The steam driven shipboard aircraft catapult systems have traditionally used qualified aviation

  14. Catapult effect in pole vaulting: is muscle coordination determinant?

    Science.gov (United States)

    Frère, Julien; Göpfert, Beat; Hug, François; Slawinski, Jean; Tourny-Chollet, Claire

    2012-02-01

    This study focused on the phase between the time of straightened pole and the maximum height (HP) of vaulter and aimed at determining the catapult effect in pole vaulting on HP. Seven experienced vaulters performed 5-10 vaults recorded by two video cameras, while the surface electromyography (sEMG) activity of 10 upper limbs muscles was recorded. HP was compared with an estimated maximum height (HP(est)) allowing the computation of a push-off index. Muscle synergies were extracted from the sEMG activity profiles using a non-negative matrix factorization algorithm. No significant difference (p>0.47) was found between HP(est) (4.64±0.21m) and HP (4.69±0.23m). Despite a high inter-individual variability in sEMG profiles, two muscle synergies were extracted for all the subjects which accounted for 96.1±2.9% of the total variance. While, the synergy activation coefficients were very similar across subjects, a higher variability was found in the muscle synergy vectors. Consequently, whatever the push-off index among the pole vaulters, the athletes used different muscle groupings (i.e., muscle synergy vectors) which were activated in a similar fashion (i.e., synergy activation coefficients). Overall, these results suggested that muscle coordination adopted between the time of straightened pole and the maximum height does not have a major influence on HP.

  15. Catapult current sheet relaxation model confirmed by THEMIS observations

    Science.gov (United States)

    Machida, S.; Miyashita, Y.; Ieda, A.; Nose, M.; Angelopoulos, V.; McFadden, J. P.

    2014-12-01

    In this study, we show the result of superposed epoch analysis on the THEMIS probe data during the period from November, 2007 to April, 2009 by setting the origin of time axis to the substorm onset determined by Nishimura with THEMIS all sky imager (THEMS/ASI) data (http://www.atmos.ucla.edu/~toshi/files/paper/Toshi_THEMIS_GBO_list_distribution.xls). We confirmed the presence of earthward flows which can be associated with north-south auroral streamers during the substorm growth phase. At around X = -12 Earth radii (Re), the northward magnetic field and its elevation angle decreased markedly approximately 4 min before substorm onset. A northward magnetic-field increase associated with pre-onset earthward flows was found at around X = -17Re. This variation indicates the occurrence of the local depolarization. Interestingly, in the region earthwards of X = -18Re, earthward flows in the central plasma sheet (CPS) reduced significantly about 3min before substorm onset. However, the earthward flows enhanced again at t = -60 sec in the region around X = -14 Re, and they moved toward the Earth. At t = 0, the dipolarization of the magnetic field started at X ~ -10 Re, and simultaneously the magnetic reconnection started at X ~ -20 Re. Synthesizing these results, we can confirm the validity of our catapult current sheet relaxation model.

  16. Disorienting effects of aircraft catapult launchings. II. Visual and postural contributions.

    Science.gov (United States)

    Cohen, M M

    1976-01-01

    Gx accelerations approximating those encountered in aircraft catapult launchings were generated on the human centrifuge Dynamic Flight Simulator at the Naval Air Development Center. Each of four catapult-experienced Naval aviators continuously oriented himself to the gravitational vertical both before and after exposure to the accelerations under two conditions: a) while he sat in total darkness, and b) while he viewed a small target projected at eye level in his mid-sagittal plane. The accelerations produce changes of pitch orientation that were affected by the presence or absence of the target, and the changes of orientation persisted well after the accelerations were terminated. Visual and postural illusions and their contributions to the disorientation are discussed, and the disorientation is related to certain water-collision accidents that have been reported to occur following aircraft catapult launchings at night.

  17. Design of image correction algorithm based on Catapult C Synthesis%基于 Catapult C Synthesis 的图像校正算法设计

    Institute of Scientific and Technical Information of China (English)

    李杨

    2016-01-01

    The jitter of remote sensor during exercise will cause the image position shift .To settle this problem ,a real‐time image correction algorithm is proposed .However ,the design of algorithm by using HDL has great difficulty and it leads to long development cycle .Therefore ,the design of algorithm is achieved by adopting C language .Then the abstract C algorithm is translated to RLT code by means of Calypto’s Catapult C Synthesis tools .Furthermore ,a co‐simulation test of C/C+ + and RLT is carried out in Catapult C Synthesis tools .It’s also verified in the platform of XC5VLX110T .The results of Simulation test and hardware verification show that the algorithm designed by applying Catapult C Synthesis tools can meet the design requirements both in timing and performance .And it can correct the shifted image in real‐time .%为解决遥感相机在运动过程中的抖动造成的图像位置偏移问题,提出了一种实时图像校正算法。由于在FPGA中采用HDL进行算法设计难度大、开发周期长,故设计中采用了C语言进行算法设计,然后借助Calypto公司的Catapult C Synthesis工具将抽象的C设计转换成硬件RTL代码。在Catapult C Synthesis中对设计的算法进行了C/C++、RLT协同仿真测试,并在Xilinx XC5VLX110T型FPGA上进行了验证。仿真测试及硬件验证结果表明,采用Catapult C Synthesis设计的算法在时序、性能方面均满足设计要求,能够对偏移的图像进行实时校正。

  18. Catapult mechanism renders the chaperone action of Hsp70 unidirectional.

    Science.gov (United States)

    Gisler, S M; Pierpaoli, E V; Christen, P

    1998-06-19

    Molecular chaperones of the Hsp70 type promote the folding and membrane translocation of proteins. The interaction of Hsp70s with polypeptides is linked to ATP binding and hydrolysis. We formed complexes of seven different fluorescence-labeled peptides with DnaK, the Hsp70 homolog of Escherichia coli, and determined the rate of peptide release under two different sets of conditions. (1) Upon addition of ATP to nucleotide-free peptide.DnaK complexes, all tested peptides were released with similar rate constants (2.2 s-1 to 6.7 s-1). (2) In the binding equilibrium of peptide and ATP-liganded DnaK, the dissociation followed one or two-step reactions, depending on the amino acid sequence of the peptide. For the monophasic reactions, the dissociation rate constants diverged by four orders of magnitude from 0.0004 s-1 to 5.7 s-1; for the biphasic reactions, the rate constants of the second, slower isomerization step were in the range from 0.3 s-1 to 0.0005 s-1. The release of the different peptides in case (1) is 1.4 to 14,000 times faster than in case (2). Apparently, binding of ATP induces a transient state of the chaperone which ejects target peptides before the final state of ATP-liganded DnaK is reached. This "catapult" mechanism provides the chaperone cycle with a mode of peptide release that does not correspond with the reverse of peptide binding. By allowing the conformation of the outgoing polypeptide to differ from that of the incoming polypeptide, a futile cycle with respect to conformational work exerted on the target protein is obviated.

  19. Experimental and Analysis for Self-excited Pressure Oscillations and Noise of Hydraulic Jet Pipe Servo-valve%液压射流管伺服阀自激振荡和噪声实验与分析

    Institute of Scientific and Technical Information of China (English)

    邹贤珍

    2016-01-01

    在液压流场中,液压伺服阀的高频噪声主要来自于自身的震荡。采用压电式动态压力传感器和扩音器对液压射流管伺服阀的自激振荡和噪声进行检测。试验中,将伺服阀的进口压力控制在11~21 MPa。为了将实验数据精准化,利用FFT和小波分析法对压力震荡信号和噪声信号进行处理。根据分析结果找出自激振荡和噪声产生的原因,并为降低液压伺服阀的自激振荡和噪声提供了方法。%In the hydraulic flow field, the high frequency noise of the hydraulic servo-valve is mainly derived from its own shock. Using the piezoelectric dynamic pressure sensor and amplifier, hydraulic jet pipe servo-valve self-excited vibration and noise were de-tected.In the test, the inlet pressure of the servo-valve was controlled in 11~21 MPa.In order to make the experimental data accurate, FFT and wavelet analysis method were used to deal with the pressure oscillation signal and noise signal.According to the analysis re-sults, the causes of the self-excited oscillation and noise were found out.It provides method for reducing vibration and noise of hydrau-lic servo-valve.

  20. Low Acceleration Overload Catapult Technique for Throwing the Small Scout Robot

    Directory of Open Access Journals (Sweden)

    Jianzhong Wang

    2016-09-01

    Full Text Available The small scout robot is generally thrown into the war zone by soldier. The short thrown distance and the danger of soldier exposed to the enemy limit the application of the small scout robot. So this paper presents a type of low acceleration overload catapult device of no flash, no smoke and no sound. It can throw the small scout robot covertly to long distances with low acceleration overload, and avoid the danger that soldier be exposed to the enemy when artificial throwing. The high and low pressure chambers of the catapult device achieve the low acceleration overload launching, and eliminate the risk of robot damaged by huge acceleration overload. The covert launching of no flash, no smoke and no sound is achieved by the piston to seal the gun propellant gas in barrel. Based on the interior ballistic model, the interior ballistic performance is calculated. The experiment for measuring the acceleration overload of the projectile is achieved by using the catapult device prototype and the measurement system developed by authors. The simulation and test results show that this catapult device can meet the requirement to throw the small scout robot into the war zone.

  1. Evidence for a vertebrate catapult: elastic energy storage in the plantaris tendon during frog jumping.

    Science.gov (United States)

    Astley, Henry C; Roberts, Thomas J

    2012-06-23

    Anuran jumping is one of the most powerful accelerations in vertebrate locomotion. Several species are hypothesized to use a catapult-like mechanism to store and rapidly release elastic energy, producing power outputs far beyond the capability of muscle. Most evidence for this mechanism comes from measurements of whole-body power output; the decoupling of joint motion and muscle shortening expected in a catapult-like mechanism has not been demonstrated. We used high-speed marker-based biplanar X-ray cinefluoroscopy to quantify plantaris muscle fascicle strain and ankle joint motion in frogs in order to test for two hallmarks of a catapult mechanism: (i) shortening of fascicles prior to joint movement (during tendon stretch), and (ii) rapid joint movement during the jump without rapid muscle-shortening (during tendon recoil). During all jumps, muscle fascicles shortened by an average of 7.8 per cent (54% of total strain) prior to joint movement, stretching the tendon. The subsequent period of initial joint movement and high joint angular acceleration occurred with minimal muscle fascicle length change, consistent with the recoil of the elastic tendon. These data support the plantaris longus tendon as a site of elastic energy storage during frog jumping, and demonstrate that catapult mechanisms may be employed even in sub-maximal jumps.

  2. INSEAN REPORT DESCRIBING THE DESIGN OF THE CRANE AND THE CATAPULT SYSTEM FOR GUIDED DITCHING TESTS

    OpenAIRE

    Iafrati, Alessandro

    2012-01-01

    The present report describes the key points of the design of the facility to be used for the guided ditching test in T4.1. The system is made by three main components: guide, trolley, acceleration and release system (catapult). Each component is illustrated separately in the following.

  3. Open Innovation, Triple Helix and Regional Innovation Systems: Exploring CATAPULT Centres in the UK

    Science.gov (United States)

    Kerry, Christopher; Danson, Michael

    2016-01-01

    Through the lens of UK CATAPULT Centres this conceptual paper presents an examination of the links between open innovation, the Triple Helix model and regional innovation systems. Highlighting the importance of boundary-spanning intermediaries, the combined role of these concepts is explored in detail. A conceptual model is then proposed which…

  4. The Cell Therapy Catapult: growing a U.K. cell therapy industry generating health and wealth.

    Science.gov (United States)

    Thompson, Keith; Foster, Emma Palmer

    2013-12-01

    In a recent report on the regenerative medicine sector, the U.K. House of Lords made several recommendations to enable the United Kingdom to become a global leader in this important industry. Its recommendations in this regard were many and various, covering the regulatory system, clinical trials, manufacturing, funding, approval, and reimbursement. In its mission to tackle what it sees as three main types of barriers to the development of the cell therapy industry in the United Kingdom, the Cell Therapy Catapult is tackling many of these issues. Established as a center of excellence in the United Kingdom in 2012, the Cell Therapy Catapult is a research organization expected to grow to a team of around 100 experts. Its core financing of £ 70 million over the next 5 years is provided by the Technology Strategy Board, the United Kingdom's innovation agency, and with additional contract research income and access to collaborative funds, the Catapult expects to build up to annual revenues of around £ 30 million. Along with its sister Catapult programs in other areas of the economy, the Cell Therapy Catapult was established after identification of the massive early-stage expertise the country has, as well as an acute market failure-the lack of expertise to translate early-stage cell therapy research into commercial success. In this article, in addition to showing our progress so far, we will discuss the hurdles the industry faces-grouped into business, manufacturing/supply chain issues, and clinical/regulatory issues-and what we are doing to help the United Kingdom leap over them.

  5. Advanced Performance Hydraulic Wind Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  6. The game of catapult to understand the design of experiments: one proposal of playful approach for teaching

    Directory of Open Access Journals (Sweden)

    Noel Torres Júnior

    2014-08-01

    Full Text Available This paper proposes the use of the Catapult game for teaching design of experiments. This game consists of a small catapult capable of launching small objects. This can have different settings, so up to five control variables can be changed. The possibility of introducing different adjustments to the catapult allows driving of several types of treatments and the use of various DOE techniques. In this direction, one 2k factorial experiment was performed and is presented. Moreover, the text addresses the DOE through the Multiple Linear Regression using the regression coefficient R2 as a measure for assessing the significance of the factors and the interaction between them. Despite the simplicity of the catapult device, several existing activities in conducting industrial experiments are present in this game. This work provides several important concepts of this technique through play.

  7. Scaling approach and thermal-hydraulic analysis in the reactor cavity cooling system of a high temperature gas -cooled reactor and thermal-jet mixing in a sodium fast reactor

    Science.gov (United States)

    Omotowa, Olumuyiwa A.

    This dissertation develops and demonstrates the application of the top-down and bottom-up scaling methodologies to thermal-hydraulic flows in the reactor cavity cooling system (RCCS) of the high temperature gas reactor (HTGR) and upper plenum of the sodium fast reactor (SFR), respectively. The need to integrate scaled separate effects and integral tests was identified. Experimental studies and computational tools (CFD) have been integrated to guide the engineering design, analysis and assessment of this scaling methods under single and two-phase flow conditions. To test this methods, two applicable case studies are considered, and original contributions are noted. Case 1: "Experimental Study of RCCS for the HTGR". Contributions include validation of scaling analysis using the top-down approach as guide to a ¼-scale integral test facility. System code, RELAP5, was developed based on the derived scaling parameters. Tests performed included system sensitivity to decay heat load and heat sink inventory variations. System behavior under steady-state and transient scenarios were predicted. Results show that the system has the capacity to protect the cavity walls from over-heating during normal operations and provide a means for decay heat removal under accident scenarios. A full width half maximum statistical method was devised to characterize the thermal-hydraulics of the non-linear two-phase oscillatory behavior. This facilitated understanding of the thermal hydraulic coupling of the loop segments of the RCCS, the heat transfer, and the two-phase flashing flow phenomena; thus the impact of scaling overall. Case 2: "Computational Studies of Thermal Jet Mixing in SFR". In the pool-type SFR, susceptible regions to thermal striping are the upper instrumentation structure and the intermediate heat exchanger (IHX). We investigated the thermal mixing above the core to UIS and the potential impact due to poor mixing. The thermal mixing of dual-jet flows at different

  8. 一种多层长井段油水井解堵水力喷射棒的研制%Development of a Kind of Hydraulic Jet Bar for Multilayer Long Interval Oil-water Well Plug Removal

    Institute of Scientific and Technical Information of China (English)

    杜勇; 李军; 刘江涛; 滕学伟; 宾永锋

    2012-01-01

    由于常规水射流工具存在处理范围小、重复起下管柱作业等问题,使其在多层长井段油水井中应用效果较差,一定程度上影响了处理效果。为此,研制了一种适用于多层长井段油水井解堵水力喷射棒。该喷射棒在其底部安装了喷嘴,围绕喷头本体螺旋设置喷嘴,扩大了处理范围。它可根据不同井段长度的需要来设计喷头本体的长度,螺旋设置各种喷嘴,使其用于较短井段时,其水力冲击更均匀,效果更好,可实现对地层的综合处理。现场应用结果表明,该喷射棒与常规工具相比,提高了处理范围,且处理效果好;有效解决了长井段均匀酸化问题,为油水井解除近井污染、实现增产增注提供了技术支持。%The small treatment scope of conventional water jet tool and repeated trip runs give rise to its poor application effect in multilayer long interval oil-water well. This affects the effect of treatment in some degree. Therefore, a type of hydraulic jet bar suitable for muhilayer long interval oil-water well plug removal was developed. The nozzle was installed on the bottom of the bar and it was set up helically around the nozzle body, thus enlarging the scope of treatment. The length of the nozzle body can be designed according to the requirement of dif- ferent well interval lengths, and various nozzles can be set up helically. When it is applied to relatively short inter- vals, the hydraulic impact is more even with a better effect. The comprehensive treatment of formation can be a- chieved. The field application shows that compared with conventional tools, the jet bar has improved the scope of treatment with a better effect. The acidization problem of long intervals has been solved effectively, providing the technological support for eliminating near wellbore pollution in oil-water well and achieving yield and injection increase.

  9. Characteristics of solid aerosols produced by optical catapulting studied by laser-induced breakdown spectroscopy

    Science.gov (United States)

    Fortes, F. J.; Laserna, J. J.

    2010-08-01

    Optical catapulting (OC) constitutes an effective method to transport small amounts of different materials in the form of a solid aerosol. In this report, laser-induced breakdown spectroscopy (LIBS) is used for the analysis of those aerosols produced by OC. For this purpose, materials were catapulted using a Q-switch Nd:YAG laser. A second Q-switch Nd:YAG laser was used for LIBS analysis of the ejected particles. Data processing of aerosols was conducted using conditional data analysis. Also, the standard deviation method was used for the qualitative identification of the ejected particles. Two modes of interaction in OC (OC with focused or defocused pulses) have been evaluated and discussed. LIBS demonstrates that the distribution (spreading) of the ejected particles along the propagation axis increased as a function of the interpulse delay time. The mass density and the thickness of the target also play an important role in OC-LIBS.

  10. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  11. HYDRAULIC SERVO

    Science.gov (United States)

    Wiegand, D.E.

    1962-05-01

    A hydraulic servo is designed in which a small pressure difference produced at two orifices by an electrically operated flapper arm in a constantly flowing hydraulic loop is hydraulically amplified by two constant flow pumps, two additional orifices, and three unconnected ball pistons. Two of the pistons are of one size and operate against the additional orifices, and the third piston is of a different size and operates between and against the first two pistons. (AEC)

  12. Application of hydraulic pulse cavitating jet technology in unconventional well drilling%水力脉冲空化射流技术在非常规钻井中的应用

    Institute of Scientific and Technical Information of China (English)

    辛建华

    2012-01-01

    For some unconventional wells, due to old stratum and poor drillability, it takes longer drilling period and encounters more complex situation, including obvious decline of mechanical drilling rate and soaring drilling cost. Based on the drilling prac-tice of unconventional wells, it is found that conventional drilling technique cannot slove the problems of low mechanical drilling rate and long drilling period. Through research, oil experts found that, under the conditions of fixed hydraulic parameters, the use of pulse jet and cavitating jet could have a greater impact load, improve the efficiency of rock clearing and rock breaking, and success-fully resolve the problem of low mechanical drilling rate and long drilling period. By tracking and comparative analysis of the appli-cation of hydraulic pulse cavitating jet technology in the drilling of unconventional wells, this paper researched on the feasibility of enhancing mechanical drilling rate by the technology and explored the means to improve the tools structure of the technology, hy-draulic parameters, drilling tools combination and the adaptability of the technology to stratum. All the researches above were of practical meanings in making technical preparation for the improvement of mechanical drilling rate of unconventional wells.%部分非常规井由于地层古老,岩性致密,可钻性差,钻井周期长,钻井过程中遇到的复杂情况增多,机械钻速下降幅度明显增大,同时钻井成本也急剧增加。从非常规钻井施工实际不难发现,采用传统钻井工艺和方式不能解决钻井机械钻速低,钻井周期长等难题。目前,石油专家通过探索研究发现,在水力参数不变的条件下,利用脉冲射流和空化射流能够产生较大的冲击载荷,提高清岩和破岩效率,从而顺利解决了钻井机械钻速低,钻井周期长等难题。通过跟踪、对比分析水力空化射流钻井技术在非常规钻井中的应

  13. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  14. Spinning hydraulic jump

    Science.gov (United States)

    Abderrahmane, Hamid; Kasimov, Aslan

    2013-11-01

    We report an experimental observation of a new symmetry breaking of circular hydraulic jump into a self-organized structure that consists of a spinning polygonal jump and logarithmic-spiral waves of fluid elevation downstream. The waves are strikingly similar to spiral density waves in galaxies. The fluid flow exhibits counterparts of salient morphological features of galactic flows, in particular the outflow from the center, jets, circum-nuclear rings, gas inflows toward the galactic center, and vortices. The hydrodynamic instability revealed here may have a counterpart that plays a role in the formation and sustainability of spiral arms in galaxies.

  15. Basic hydraulics

    CERN Document Server

    Smith, P D

    1982-01-01

    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  16. Mechanical Analysis and Field Application of Coiled Tubing Hydraulic Jet Fracturing String%连续管水力喷射压裂管柱力学分析及现场应用

    Institute of Scientific and Technical Information of China (English)

    王鹏; 王思淇; 张倩

    2016-01-01

    To address the stability issue of coiled tubing operation, the stress and elongation of two kinds of hy⁃draulic jet annulus sand delivery fracturing string have been analyzed in the whole process of operation in Daqing oil⁃field�The main research include: (1) Stress and deformation analysis of the coiled tubing hydraulic jet fracturing string in the whole operation, and the corresponding mathematical model; (2) Analysis on the two common packer K344 and Y211 during fracturing; processing methods of the boundary conditions at the bottom of the fracturing string during the setting of different packers; (3) Calculation of the deformation and stress of the coiled tubing fracturing string during fracturing operation of Well Gulongnan P , and comparison with the field measured data�Analysis results showed that the mechanical model results have a small deviation with the measured data�The research results could provide theoretical guidance for coiled tubing hydraulic jet fracturing operation design and construction.%连续管水力喷射压裂技术结合了水力喷射射孔定点压裂的优越性与连续管的拖动灵活性,极大地提高了水力喷射压裂作业的工作效率。为解决该技术存在的连续管作业稳定性较差的问题,以大庆油田2种水力喷射环空加砂压裂工艺管柱为例,对管柱进行了全作业过程受力分析及伸长量分析,主要包括:(1)分析管柱全作业过程受力及变形,并给出了相应的计算模型;(2)分析K344和Y2112种常用封隔器压裂作业工况,给出了不同封隔器坐封时压裂管柱底部边界条件处理方法;(3)实例计算分析古龙南P井连续管压裂作业时管柱受力变形,并与现场实测数据进行了对比分析。分析结果表明:力学计算模型计算结果与现场实测数据偏差较小。研究成果能够为连续管水力喷射压裂作业设计施工提供理论指导。

  17. The Technical Analysis of Unmanned Aircraft Catapult Launch%无人机弹射起飞技术分析

    Institute of Scientific and Technical Information of China (English)

    孙志宏

    2014-01-01

    针对无人机起飞安全问题,介绍了利用弹射架弹射起飞方式来提高无人机起飞安全系数,并详细阐述了弹射架种类及工作原理。%Aiming at the Security issues of Unmanned aircraft take off , the paper introduces that improving the safety factor of Un-manned Aircraft take off by using the technology of Catapult Launch , also introduces the Catapult Launch's species and principle .

  18. Pilot disorientation during aircraft catapult launchings at night - Historical and experimental perspectives

    Science.gov (United States)

    Cohen, Malcolm M.

    1992-01-01

    A review is presented of the investigations conducted into, and the recommendations made to avoid fatal A-7 Corsair II aircraft accidents during night carrier launchings in which the aircraft was apparently flown into the water. The investigating boards conjectured that the pilots were distracted from their normal cockpit procedures and that the distraction was of an insidious nature not previously experienced or expected in the night catapult/departure environment. A conference to discuss these accidents focused on aerodynamic and human factors analyses of the problem, with the goal of producing several recommendations for its resolution.

  19. Low Acceleration Overload Catapult Technique for Throwing the Small Scout Robot

    OpenAIRE

    Jianzhong Wang; Jiadong Shi; Tao Jiang

    2016-01-01

    The small scout robot is generally thrown into the war zone by soldier. The short thrown distance and the danger of soldier exposed to the enemy limit the application of the small scout robot. So this paper presents a type of low acceleration overload catapult device of no flash, no smoke and no sound. It can throw the small scout robot covertly to long distances with low acceleration overload, and avoid the danger that soldier be exposed to the enemy when artificial throwing. The high and lo...

  20. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  1. The UAV Airfoil Aerodynamic Interference of Missile Launched from Rail-catapult Integrated Launcher%无人机导弹滑弹一体式发射对机翼的气动干扰

    Institute of Scientific and Technical Information of China (English)

    王博; 马贵春; 陈阳; 董浩

    2016-01-01

    无人机机载导弹发射产生的尾喷流对机翼的气动干扰影响载机飞行安全。本研究以Fluent软件为基础,采用二维非结构动网格技术并选择标准k-ω二方程湍流模型,对导弹沿导轨弹射滑行后点火和直接点火的发射过程分别进行数值模拟,并对两组结果进行对比。结果表明:滑弹一体式发射装置在一定程度上降低导弹尾喷流对机翼的气动影响。该研究为无人机导弹滑弹一体式发射装置的研究提供一定参考。%When airborne missile launched from UAV , its exhaust jet has an impact on UAV airfoil and safety .This study is based on two-dimensional unstructured dynamic grids and standard k-omega tow-equation turbulence model of the software Fluent .In this research differ-ence between missile ignition firing and ignition firing after ejection was analyzed , and these two results were compared .The results show that the rail-catapult integrated launcher can reduce aerodynamic influence on airfoil caused by missile exhaust jet stream .The results will provide certain reference for research of rail-catapult integrated missile launcher of UAV .

  2. Targeting pancreatic islets with phage display assisted by laser pressure catapult microdissection.

    Science.gov (United States)

    Yao, Virginia J; Ozawa, Michael G; Trepel, Martin; Arap, Wadih; McDonald, Donald M; Pasqualini, Renata

    2005-02-01

    Heterogeneity of the microvasculature in different organs has been well documented by multiple methods including in vivo phage display. However, less is known about the diversity of blood vessels within functionally distinct regions of organs. Here, we combined in vivo phage display with laser pressure catapult microdissection to identify peptide ligands for vascular receptors in the islets of Langerhans in the murine pancreas. Protein database analyses of the peptides, CVSNPRWKC and CHVLWSTRC, showed sequence identity to two ephrin A-type ligand homologues, A2 and A4. Confocal microscopy confirmed that most immunoreactivity of CVSNPRWKC and CHVLWSTRC phage was associated with blood vessels in pancreatic islets. Antibodies recognizing EphA4, a receptor for ephrin-A ligands, were similarly associated with islet blood vessels. Importantly, binding of both islet-homing phage and anti-EphA4 antibody was strikingly increased in blood vessels of pancreatic islet tumors in RIP-Tag2 transgenic mice. These results indicate that endothelial cells of blood vessels in pancreatic islets preferentially express EphA4 receptors, and this expression is increased in tumors. Our findings show in vivo phage display and laser pressure catapult microdissection can be combined to reveal endothelial cell specialization within focal regions of the microvasculature.

  3. Production of aerosols by optical catapulting: Imaging, performance parameters and laser-induced plasma sampling rate

    Science.gov (United States)

    Abdelhamid, M.; Fortes, F. J.; Fernández-Bravo, A.; Harith, M. A.; Laserna, J. J.

    2013-11-01

    Optical catapulting (OC) is a sampling and manipulation method that has been extensively studied in applications ranging from single cells in heterogeneous tissue samples to analysis of explosive residues in human fingerprints. Specifically, analysis of the catapulted material by means of laser-induced breakdown spectroscopy (LIBS) offers a promising approach for the inspection of solid particulate matter. In this work, we focus our attention in the experimental parameters to be optimized for a proper aerosol generation while increasing the particle density in the focal region sampled by LIBS. For this purpose we use shadowgraphy visualization as a diagnostic tool. Shadowgraphic images were acquired for studying the evolution and dynamics of solid aerosols produced by OC. Aluminum silicate particles (0.2-8 μm) were ejected from the substrate using a Q-switched Nd:YAG laser at 1064 nm, while time-resolved images recorded the propagation of the generated aerosol. For LIBS analysis and shadowgraphy visualization, a Q-switched Nd:YAG laser at 1064 nm and 532 nm was employed, respectively. Several parameters such as the time delay between pulses and the effect of laser fluence on the aerosol production have been also investigated. After optimization, the particle density in the sampling focal volume increases while improving the aerosol sampling rate till ca. 90%.

  4. Bias determination for space accelerometers using the ZARM Catapult system - experimental setup and data analysis

    Science.gov (United States)

    Selig, Hanns; Santos Rodrigues, Manuel; Touboul, Pierre; Liorzou, Françoise

    2012-07-01

    Accelerometers for space applications - like the electrostatic differential accelrometer for the MICROSCOPE mission for testing the equivalence principle in space - have to be tested and qualified in μg-conditions in order to demonstrate the system operation and to determine the characteristic sensor parameters. One important characteristic property is the sensor bias. In principle one can determine the sensor bias directly by using the ZARM catapult system as test platform. Even in the evacuated drop tube the residual air pressure results in an air friction that depends on the capsule velocity. At the apex (highest point of the capsule trajectory) the acceleration (relative to the gravitational acceleration g) becomes zero due to the zero velocity at the apex. The direct measurement of the vertical linear acceleration sensor bias is affected by some additional effects that have to be understood in order to be able to determine the sensor bias. Two catapult campaigns have been carried out to demonstrate the principles of the bias determination using a SuperStar accelerometer (Onera). The presentation gives an overview on the experimental setup and on the corresponding data analysis.

  5. Multi-agent Based Hierarchy Simulation Models of Carrier-based Aircraft Catapult Launch

    Institute of Scientific and Technical Information of China (English)

    Wang Weijun; Qu Xiangju; Guo Linliang

    2008-01-01

    With the aid of multi-agent based modeling approach to complex systems,the hierarchy simulation models of carrier-based aircraft catapult launch are developed.Ocean,carrier,aircraft,and atmosphere are treated as aggregation agents,the detailed components like catapult,landing gears,and disturbances are considered as meta-agents,which belong to their aggregation agent.Thus,the model with two layers is formed i.e.the aggregation agent layer and the meta-agent layer.The information communication among all agents is described.The meta-agents within one aggregation agent communicate with each other directly by information sharing,but the meta-agents,which belong to different aggregation agents exchange their information through the aggregation layer fast,and then perceive it from the sharing environment,that is the aggregation agent.Thus,not only the hierarchy model is built,but also the environment perceived by each agent is specified.Meanwhile,the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system (MAS) is resolved.Each agent involved in carrier-based aircraft catapult launch is depicted,with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier,aircraft,and landing gears.The models of reactive agents among them are derived based on tensors,and the perceived messages and inner frameworks of each agent are characterized.Finally,some results of a simulation instance are given.The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely.The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system.This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent,and it is convenient to expand,maintain,and reuse

  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. Pollen Dispersal by Catapult: Experiments of Lyman J. Briggs on the Flower of Mountain Laurel

    Science.gov (United States)

    Nimmo, John R.; Hermann, Paula M.; Kirkham, M. B.; Landa, Edward R.

    2014-09-01

    The flower of Kalmia latifolia L. employs a catapult mechanism that flings its pollen to considerable distances. Physicist Lyman J. Briggs investigated this phenomenon in the 1950s after retiring as longtime director of the National Bureau of Standards, attempting to explain how hydromechanical effects inside the flower's stamen could make it possible. Briggs's unfinished manuscript implies that liquid under negative pressure generates stress, which, superimposed on the stress generated from the flower's growth habit, results in force adequate to propel the pollen as observed. With new data and biophysical understanding to supplement Briggs's experimental results and research notes, we show that his postulated negative-pressure mechanism did not play the exclusive and crucial role that he credited to it, though his revisited investigation sheds light on various related processes. Important issues concerning the development and reproductive function of Kalmia flowers remain unresolved, highlighting the need for further biophysical advances.

  8. Heterosis, the catapult effect and establishment success of a colonizing bird.

    Science.gov (United States)

    Drake, John M

    2006-06-22

    The genetic basis of population colonization is poorly understood, particularly in animals. Here, I introduce the idea of a 'catapult effect' to explain how the effects of transient increases in fitness can be retained in population demography diminishing the chance of extinction. I tested this idea using information on historical introductions of hybrid and non-hybrid pheasants in the United States. I found that hybrid pheasants were 2.2 times more likely to establish than non-hybrid strains. Analysis of fitness components failed to support the alternative that the increased odds of establishment resulted from increased genetic variation conferring permanent fitness benefits through directional selection or by purging deleterious alleles. These results show that even ephemeral increases in fitness can affect the persistence of small populations.

  9. Physicochemical characterization of wet microalgal cells disrupted with instant catapult steam explosion for lipid extraction.

    Science.gov (United States)

    Cheng, Jun; Huang, Rui; Li, Tao; Zhou, Junhu; Cen, Kefa

    2015-09-01

    Instant catapult steam explosion (ICSE) was employed to disrupt wet microalgal cells for efficient lipid extraction. Physicochemical properties of exploded cells were investigated through SEM, TEM, FTIR, and TGA. The exploded cells increased in fractal dimension (1.53-1.65) when preheat time was prolonged from 0 min to 5 min and in surface pore area when steam pressure was increased. Meanwhile, the exploded cells decreased in mean size (1.69-1.44 μm) when the filling ratio of wet microalgal biomass in the preheat chamber decreased (75-12.5%). Flash evaporation and volume expansion exploded the cell walls and released the cytoplasm of the microalgal cells. These phenomena decreased the carbohydrate content and increased the lipid content in the exploded biomass. However, ICSE treatment did not change the lipid compositions in the microalgal cells. Using isopropanol as a cosolvent significantly increased the yield of lipids extracted with hexane from the exploded wet microalgal biomass.

  10. Disorienting effects of aircraft catapult launchings: III. Cockpit displays and piloting performance.

    Science.gov (United States)

    Cohen, M M

    1977-09-01

    Accelerations closely approximating those encountered in catapult launchings of carrier-based aircraft were generated on the Naval Air Development Center's human centrifuge Dynamic Flight Simulator. Flight instruments, controls, and flight dynamics of an A-7 aircraft were provided to four experienced Naval Aviators, who exercised closed-loop control of a simulated climbout immediately after they were exposed to the accelerations. Four experimental conditions were employed for each aviator: 1) no operational flight instruments, 2) conventional flight instruments, 3) a single carrier takeoff director display operating concurrently. Measures of flight parameters, including indicated airspeed, angle of attack, rate of climb, altitude, pitch attitude, and pitch trim adjustment were monitored throughout the simulation. Subjective reactions and piloting performance were examined under each of the four conditions. Results indicate that the carrier takeoff director display significantly reduced pilot workload and enhanced performance during the climbout.

  11. Assessment and regression analysis on instant catapult steam explosion pretreatment of corn stover.

    Science.gov (United States)

    Liu, Chen-Guang; Liu, Li-Yang; Zi, Li-Han; Zhao, Xin-Qing; Xu, You-Hai; Bai, Feng-Wu

    2014-08-01

    Instant catapult steam explosion (ICSE) offers enormous physical force on lignocellulosic biomass due to its extremely short depressure duration. In this article, the response surface methodology was applied to optimize the effect of working parameters including pressure, maintaining time and mass loading on the crystallinity index and glucose yield of the pretreated corn stover. It was found that the pressure was of essential importance, which determined the physical force that led to the morphological changes without significant chemical reactions, and on the other hand the maintaining time mainly contributed to the thermo-chemical reactions. Furthermore, the pretreated biomass was assessed by scanning electron microscope, X-ray diffraction and Fourier transform infrared spectra to understand mechanisms underlying the ICSE pretreatment.

  12. Two-axis hydraulic joint for high speed, heavy lift robotic operations

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, M.R.; Robinett, R.D.; Phelan, J.R.; VanZuiden, D.M.

    1994-04-01

    A hydraulically driven universal joint was developed for a heavy lift, high speed nuclear waste remediation application. Each axis is driven by a simple hydraulic cylinder controlled by a jet pipe servovalve. Servovalve behavior is controlled by a force feedback control system, which damps the hydraulic resonance. A prototype single joint robot was built and tested. A two joint robot is under construction.

  13. Chemical characterization of single micro- and nano-particles by optical catapulting-optical trapping-laser-induced breakdown spectroscopy

    Science.gov (United States)

    Fortes, Francisco J.; Fernández-Bravo, Angel; Javier Laserna, J.

    2014-10-01

    Spectral identification of individual micro- and nano-sized particles by the sequential intervention of optical catapulting, optical trapping and laser-induced breakdown spectroscopy is presented. The three techniques are used for different purposes. Optical catapulting (OC) serves to put the particulate material under inspection in aerosol form. Optical trapping (OT) permits the isolation and manipulation of individual particles from the aerosol, which are subsequently analyzed by laser-induced breakdown spectroscopy (LIBS). Once catapulted, the dynamics of particle trapping depends both on the laser beam characteristics (power and intensity gradient) and on the particle properties (size, mass and shape). Particles are stably trapped in air at atmospheric pressure and can be conveniently manipulated for a precise positioning for LIBS analysis. The spectra acquired from the individually trapped particles permit a straightforward identification of the material inspected. Variability of LIBS signal for the inspection of Ni microspheres was 30% relative standard deviation. OC-OT-LIBS permits the separation of particles in a heterogeneous mixture and the subsequent analysis of the isolated particle of interest. In order to evaluate the sensitivity of the approach, the number of absolute photons emitted by a single trapped particle was calculated. The limit of detection (LOD) for Al2O3 particles was calculated to be 200 attograms aluminium.

  14. 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.

  15. 弹射药筒局部热处理%Local Thermal Treatment on Catapult Cartridge

    Institute of Scientific and Technical Information of China (English)

    闻国民; 杨国义; 牛俊杰; 魏军伟; 陈全明

    2014-01-01

    针对弹射药筒局部热处理的质量性能要求,对感应加热技术进行研究。基于加热时间、温度和升温速度对筒壁的影响,从频率选择、感应器和工装设计3个方面进行分析,得到频率、功率和时间参数。分析结果表明:该方法使工件的抗拉强度、延伸率达到了要求,产品性能稳定,并能有效控制药筒口部的物理性能。%The technology of induction heating fusing had been researched in allusion to the demand of quality and property of the local thermal treatment on catapult cartridge. In view of the effect on cylinder wall about heating time, temperature and the rate of warming, parameter of frequency, temperature and time had been found according to the analysis in these three points including frequency selection, sensors and equipment design. Interrelated analyses concluded that these measures ensured the tensile strength and elongation, and made the performance stable. Also, physical properties of cartridge mouth had been controlled effectively.

  16. Catapult-like release of mitochondrial DNA by eosinophils contributes to antibacterial defense.

    Science.gov (United States)

    Yousefi, Shida; Gold, Jeffrey A; Andina, Nicola; Lee, James J; Kelly, Ann M; Kozlowski, Evelyne; Schmid, Inès; Straumann, Alex; Reichenbach, Janine; Gleich, Gerald J; Simon, Hans-Uwe

    2008-09-01

    Although eosinophils are considered useful in defense mechanisms against parasites, their exact function in innate immunity remains unclear. The aim of this study is to better understand the role of eosinophils within the gastrointestinal immune system. We show here that lipopolysaccharide from Gram-negative bacteria activates interleukin-5 (IL-5)- or interferon-gamma-primed eosinophils to release mitochondrial DNA in a reactive oxygen species-dependent manner, but independent of eosinophil death. Notably, the process of DNA release occurs rapidly in a catapult-like manner--in less than one second. In the extracellular space, the mitochondrial DNA and the granule proteins form extracellular structures able to bind and kill bacteria both in vitro and under inflammatory conditions in vivo. Moreover, after cecal ligation and puncture, Il5-transgenic but not wild-type mice show intestinal eosinophil infiltration and extracellular DNA deposition in association with protection against microbial sepsis. These data suggest a previously undescribed mechanism of eosinophil-mediated innate immune responses that might be crucial for maintaining the intestinal barrier function after inflammation-associated epithelial cell damage, preventing the host from uncontrolled invasion of bacteria.

  17. Pollen dispersal by catapult: Experiments of Lyman J. Briggs on the flower of mountain laurel

    Science.gov (United States)

    Nimmo, John R.; Hermann, Paula M.; Kirkham, M.B.; Landa, Edward R.

    2014-01-01

    The flower of Kalmia latifolia L. employs a catapult mechanism that flings its pollen to considerable distances. Physicist Lyman J. Briggs investigated this phenomenon in the 1950s after retiring as longtime director of the National Bureau of Standards, attempting to explain how hydromechanical effects inside the flower’s stamen could make it possible. Briggs’s unfinished manuscript implies that liquid under negative pressure generates stress, which, superimposed on the stress generated from the flower’s growth habit, results in force adequate to propel the pollen as observed. With new data and biophysical understanding to supplement Briggs’s experimental results and research notes, we show that his postulated negative-pressure mechanism did not play the exclusive and crucial role that he credited to it, though his revisited investigation sheds light on various related processes. Important issues concerning the development and reproductive function of Kalmia flowers remain unresolved, highlighting the need for further biophysical advances.

  18. 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.

  19. Analytical Study on Impingement Heat Transfer with Single—Phase Free—Surface Circular Liquid Jets

    Institute of Scientific and Technical Information of China (English)

    C.F.Ma; T.Masuoka; 等

    1996-01-01

    An analytical research was conducted to study heat transfer from horizontal surfaces to normally impinging circular jets under arbitrary-heat-flux conditions.The laminar thermal and hydraulic bound ary layers were divided into five regions of flow.General expressions of heat transfer coefficients were obtained in all the four regions of stagnation and wall jet zones before the hydraulic jump.

  20. Implement complex DSP Algorithm rapidly by Mentor High level Synthesis tool (Catapult Synthesis)%利用Mentor高层次综合技术(Catapult Synthesis)快速实现复杂DSP算法

    Institute of Scientific and Technical Information of China (English)

    游余新

    2007-01-01

    为了满足产品上市时间和功能丰富性的要求,越来越多的先进设计公司开始提高设计的抽象层次进行复杂的DSP硬件设计,从RTL级提高到C/C++,以保持产品的持续领先地位.Mentor Graphics的高层次综合工具(Catapult Synthesis)是第一个综合标准的ANSI C++的产品,它可无误地生成针对ASIC/FPGA的高质量RTL代码,且速度比手工编码的快10-20倍.本文以FIR的实现为例,利用Catapult Synthesi s快速探索不同的设计架构,快速地找到性能、面积和功耗之间折衷的最佳实现方案,使得真正的IP复用成为可能,并以图表方式给出不同约束下的面积、延迟和吞吐率(36、3、1时钟周期)的性能,同时提供了集成的验证和综合流程,极大地提高了设计效率.

  1. 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...

  2. Hydraulic conductivity and diffusion characterization of GCLs

    Energy Technology Data Exchange (ETDEWEB)

    Mukunoki, T.; Rowe, R.K.; Li, H.M.; Sangam, H.P.; Hurst, P.; Bathurst, R.J. [Queen' s Univ., Kingston, ON (Canada)]|[Royal Military Coll. of Canada, Kingston, ON (Canada); Badv, K. [Urmia Univ. (Iran, Islamic Republic of)

    2003-07-01

    This paper reports on the characterization of the hydraulic conductivity and diffusion of a geosynthetic clay liner (GCL) installed at a site off the southeast coast of Baffin Island, in the Canadian Arctic, following different levels of freeze-thaw exposure and under low temperature conditions. The authors presented a summary of the results obtained for hydraulic conductivity tests on GCLs subjected to freeze-thaw cycles, and specimens permeated with jet fuel (Arctic diesel). They also reported on diffusion tests conducted at 22 Celsius and 5 Celsius, followed by a discussion of the effect of temperature. The results indicate that there is no significant impact on GCL performance due to freeze-thaw cycles, permeation by jet fuel or diffusion at the lower temperatures expected in the north for the short term (up to approximately four years). Additional studies are needed to confirm long term behaviour. 24 refs., 2 tabs., 4 figs.

  3. Outline of a Twenty-Five Year Plan for Development and Deployment of A Catapult for A Third Generation Space Shuttle

    Science.gov (United States)

    Russell, John M.

    2002-01-01

    This report reviews the rationale for catapult assist in the launching a third generation space shuttle. It then furnishes lists of early design decisions, questions whose answers are prerequisite to later design decisions, preliminary inventories of carriage levitation and carriage propulsion concepts, phases of the project and major milestones, and some sources of expertise to support the project.

  4. 舰载机蒸汽弹射动力学仿真分析%Dynamics Simulation of Carrier-based Aircraft Steam Catapult

    Institute of Scientific and Technical Information of China (English)

    张雷; 冯蕴雯; 薛小锋; 冯元生

    2012-01-01

    This article illustrates the need for a steam catapult device applications. Proposed the dynamics simulation model of carrier- based aircraft steam catapult on the basis of comprehensive consideration of the thermodynamic model, the traction release device mathematical model , aircraft kinetics model and landing gear jump and other factors. Based on C - 13 catapult and a certain type of aircraft,a simulation analysis is presented. The results,which are compared with test data,provide a useful reference for the design of carrier- based aircraft steam catapult system and experimental verification.%阐明了蒸汽弹射装置应用的必要性.在综合考虑热力学模型、牵引释放装置数学模型、舰载机动力学模型以及起落架突伸等因素的基础上,提出了舰载机蒸汽弹射动力学仿真分析模型.以C-13型弹射器和某型飞机为例进行了仿真分析,并与相关实验数据进行对比分析,其分析结果可为舰栽机蒸汽弹射系统设计以及试验验证提供有益参考.

  5. Direct polymerase chain reaction amplification of formalin-fixed, paraffin-wax-embedded tissue after automated sequential laser microdissection and pressure catapulting.

    Science.gov (United States)

    O'Kane, S L; Garimella, V; Sivarajasingham, N; Drew, P J; Cawkwell, L

    2007-02-01

    A robust method to facilitate rapid laser microdissection and pressure catapulting (LMPC) coupled with direct polymerase chain reaction (dPCR) to eliminate the need for extraction of DNA before a PCR-based assay is described. This sequential LMPC-dPCR method is rapid and decreases the number of processing steps, reducing the chance of tissue loss and contamination.

  6. HYDRAULICS, LOUISA COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic analysis for estimating flood stages for a flood insurance study. It...

  7. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  8. 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.

  9. NUMERICAL SIMULATION OF 3-D AERATED JET BEHIND FLIP BUCKET OF OVERFLOW DAM

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Aerated jet,such as the jet flow behind the flip bucket of an overflow dam, widely exists in hydraulic engineering. Up to now the model test and prototype observation have been two main methods of studying the aerated jet for a special hydraulic project. In this paper, a three-dimensional mathematical model for the aerated jet was established. It seems that the suggested model has high predictive power by comparison with the results of model tests and prototype observations, which is very useful in the study of energy dissipation and jet flow atomization.

  10. 径向射流水力压裂技术在高瓦斯矿井立井揭煤中的应用%Application of Radial Jet Hydraulic Pressurized Fracturing Technology to Seam Opening of High Gassy Mine Shaft

    Institute of Scientific and Technical Information of China (English)

    李翔; 刘林松

    2016-01-01

    Nansu Mine Income Ventilation Shaft of Zhaozhuang Mine had a designed depth of 784.5 m. When the mine shaft construction was at a depth of 724.17 m ,the mine shaft sinking was stopped. The radial jet hydraulic pressurized fracturing technology was applied to the seam opening operation of an underneath No.3 seam (high gassy seam ). After the hydraulic pressurized fracturing ,the gas pre-drainage was only conducted with 35 days and the seam had the seam opening conditions. The practices showed that the fracturing technology could play a well role to the seam permeability improved ,stress released and seam pressure bump elimination. In comparison with the conventional seam opening meth‐od ,the fracturing technology could safely and rapidly make the seam with the seam opening condi‐tions.%赵庄矿南苏进风立井设计深度784.5 m。井筒施工至724.17 m深处时,停止掘进,应用径向射流水力压裂技术,对下部的3号煤层(高瓦斯煤层)进行揭煤作业。水力压裂后,仅预抽35 d ,便使煤层具备揭煤条件。实践表明,该项技术对煤层增透、应力释放、消突可起到很好的作用,与传统揭煤方法相比,能安全快速地使煤层具备揭煤条件。

  11. 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.

  12. 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.

  13. 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...

  14. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  15. Ditching Tests with a 1/12-Scale Model of the Army A-26 Airplane in Langley Tank No. 2 and on an Outdoor Catapult

    Science.gov (United States)

    Jarvis, George A.; Hoffman, Edward L.

    1947-01-01

    Tests were conducted in calm water in Langley tank no. 2 and in calm and rough water at an outdoor catapult in order to determine the best way to make a forced landing of an Army A-26 airplane and to determine its probable ditching behavior. These tests were requested by the Air Materiel Command, Army Air Forces, in their letter of March 26, 1943, WEL:AW:50.

  16. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  17. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  18. 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.

  19. Analysis of dynamic characteristics of catapult launch for a carrier-based aircraft with sudden load discharge%考虑载荷突卸的舰载机弹射起飞动力学分析

    Institute of Scientific and Technical Information of China (English)

    朱齐丹; 李新飞; 喻勇涛

    2012-01-01

    In order to study dynamic characteristics of catapult launch for a carrier-based aircraft, a simplified dynamic model of catapult launch with sudden load discharge of nose gear was constructed. Fast vibration in the vertical direction of nose gear caused by the sudden discharge of the holdback load in the beginning of catapult launch was studied, and the dynamic reason of this phenomenon was analyzed. The rules of fast extension of nose landing gear caused by the sudden discharge of the catapult bridle load at the end of catapult launch was researched, and the influence of all parameters on the extension of nose landing gear was analyzed. Two important conclusions were obtained: in order to reduce the vibration peak value of the strain of nose landing gear during catapult launch, the holdback and catapult bridle lengths should be increased appropriately, and the maximum holdback breaking load is suggested to increase properly. Secondly, in order to decrease the difficulties of catapult launch, the catapult bridle length is recommended to decrease moderately.%为了分析舰载机弹射起飞过程中的动力学特点,建立了一种考虑前起落架载荷突卸的弹射起飞动力学模型.研究了在弹射开始时由于牵制载荷突卸而引起的前起落架沿着垂直方向的快速振动现象,并分析了该现象的动力学成因;研究了在弹射末端由于弹射杆载荷突卸而引起的前起落架的快速突伸规律,分析了各种参数对前起落架突伸的影响.结果分析表明:为了减小前起落架支柱受力的波动峰值,应适当增加弹射杆长度和牵制杆长度,及牵制杆最大破坏力值;但为了降低弹射起飞难度,应适当减小弹射杆长度.

  20. From the elastica compass to the elastica catapult: an essay on the mechanics of soft robot arm

    Science.gov (United States)

    Armanini, C.; Dal Corso, F.; Misseroni, D.; Bigoni, D.

    2017-02-01

    An elastic rod is clamped at one end and has a dead load attached to the other (free) end. The rod is then slowly rotated using the clamp. When the load is smaller than the buckling value, the rod describes a continuous set of quasi-static forms and its end traces a (smooth, convex and simple) closed curve, which would be a circle if the rod were rigid. The closed curve is analytically determined through the integration of the Euler's elastica, so that for sufficiently small loads the mechanical system behaves as an `elastica compass'. For loads higher than that of buckling, the elastica reaches a configuration from which a snap-back instability occurs, realizing a sort of `elastica catapult'. The whole quasi-static evolution leading to the critical configuration for snapping is calculated through the elastica and the subsequent dynamic motion simulated using two numerical procedures, one ad hoc developed and another based on a finite-element scheme. The theoretical results are then validated on a specially designed and built apparatus. An obvious application of the present model would be in the development of soft robotic limbs, but the results are also of interest for the optimization analysis in pole vaulting.

  1. FEMA DFIRM Hydraulic Structures

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer and accompanying attribute table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the...

  2. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on......-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical...... modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research...

  3. Constant-Pressure Hydraulic Pump

    Science.gov (United States)

    Galloway, C. W.

    1982-01-01

    Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

  4. 技术与创新中心在解决创新的"死亡之谷"问题中的作用——基于对英国Catapults项目实施效果的实证分析%Technology Innovation Centre and Its Role in Addressing the Valley of Death—— Analysis of the Effects of Catapults Program in UK

    Institute of Scientific and Technical Information of China (English)

    李振兴

    2015-01-01

    Catapults program is started and funded by UK government to address the "Valley of Death" of innovation. To date, seven Catapults such as High Value Manufacture Catapult were set up and open to public, another two Catapults named Energy System and Precise Medicine Catapult are under the way to open. The reason of Valley of Death and the unique role of Catapults playing in addressing the Valley of Death were introduced; the economics background of Catapults program and necessity of implementing Catapults program as a public policy tool were analyzed. Cases were given to illustrate how Catapults may help the business development, especially the commercialization of research and development driven by innovation.%为解决创新的"死亡之谷"难题,英国近年投入巨资建设新的技术与创新中心(Catapults).本文从"死亡之谷"的形成原因出发,介绍了技术与创新中心在破解"死亡之谷"难题中发挥的独特作用,并基于已经建成的七个Catapults 的实证,分析了Catapults 项目实施的经济学背景以及作为公共创新政策工具的必要性,通过案例分析介绍了Catapults 在实际运行中如何促进产业发展特别是促进研究商业化和创新发展,供决策参考.

  5. 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.

  6. Kilowatt Isotope Power System: component test report for the ground demonstration system jet condenser orifice performance. 77-KIPS-103

    Energy Technology Data Exchange (ETDEWEB)

    Brainard, E.L.

    1977-11-08

    The purpose of these tests was to determine which orifice elements achieved satisfactory hydraulic and thermal performance prior to their incorporation into the Jet Condenser Assembly. Requirements were as set forth within the Kilowatt Isotope Power System (KIPS) Component Test Procedure number 414 for the Jet Condenser Orifice Performance testing. The results of the performance testing conducted on the Jet Condenser Orifices are presented. Part Number 720841 Jet Condenser Orifice Nozzle successfully completed the orifice screening tests.

  7. Trend of hydraulic units

    Energy Technology Data Exchange (ETDEWEB)

    Deshimaru, Jun' ichi

    1988-11-01

    The gear, vane and piston pumps occupy a more then 90% share in the hydraulic pumps. Comparatively large pumps are mainly variable delivery piston pumps. The piston pumps are comparatively high in output density (output per unit weight), indicating the hydraulic pump in performance, and tend to become higher and higher in it. Though they are mainly 210 to 350kgf/cm/sup 2/ in rated pressure, some of them come to surpass 400kgf/cm/sup 3/ in it. While the progress in computation also requires the high speed operation, high accuracy and other severe conditions for the hydraulic units, which accordingly and increasingly intensify the requirement for hydraulic oil in abrasion resistibility, oxidation stability and response characteristics. While cavitation comes to easily occur, which considerably and disadvantageously influences hydraulic oil in life through degradation, noise level and respondingness. From now on, the development of high performance oil and study of mechanical structure are important. 19 references, 9 figures, 2 tables.

  8. Hydraulics of a multiple slit-type energy dissipater

    Institute of Scientific and Technical Information of China (English)

    吴建华; 姚莉; 马飞; 吴伟伟

    2014-01-01

    With the constructions of high dam projects in China, the energy dissipation downstream of a dam becomes a serious concern. In this study, a multiple slit-type energy dissipater, with different reduction size slits in the outlet, is developed on the basis of conventional slit-type energy dissipaters, aiming to enhance the energy dissipation through the turbulence and the friction between the different layers of the jet flow and the air entrainment due to the increased surface of the flow to the air. The hydraulic characteristics of the energy dissipater are experimentally investigated by means of three sets of physical models in nine cases, to characterize the geometric parameters with suitable performance. The main concerns are the flow regime, the jet flow trajectory, the energy dissipation, the cavitation characteristics, and the flow choking. The results indicate that the dissipater enjoys a high energy dissipation ratio with suitable hydraulic performance comparing with the conventional slit-type energy dissipaters.

  9. Ditching Tests of a 1/9-Size Model of the Army P-38 Airplane in Langley Tank No. 2 and at the Outdoor Catapult

    Science.gov (United States)

    Jarvis, George A.; Cederborg, Gibson A.

    1946-01-01

    A dynamically similar model of the Army P-38 airplane was tested to determine the best way to land this airplane on the water and to determine its probable ditching performance. The tests consisted of ditching the model at various landing attitudes, flap settings, speeds, weights, and conditions of simulated damage. The model was ditched in calm water from the tank towing carriage and a few ditching were made in both calm and rough water at the outdoor catapult. The performance of the model was determined by making visual observations, by recording lengths of run and time histories of decelerations, and by taking motion pictures of the ditchings.

  10. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  11. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew

    2006-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  12. Popeye Project: Hydraulic umbilical

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, K.G.; Williams, V.T.

    1996-12-31

    For the Popeye Project, the longest super-duplex hydraulic umbilical in the world was installed in the Gulf of Mexico. This paper reports on its selection and project implementation. Material selection addresses corrosion in seawater, water-based hydraulic fluid, and methanol. Five alternatives were considered: (1) carbon-steel with traditional coating and anodes, (2) carbon-steel coated with thermally sprayed aluminum, (3) carbon-steel sheathed in aluminum, (4) super-duplex, and (5) titanium. The merits and risks associated with each alternative are discussed. The manufacture and installation of the selected umbilical are also reported.

  13. 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...

  14. SIMULATION OF FLUID FLOW IN CHANNEL OF A NOVEL HYDRAULIC SHOCK GENERATOR

    Institute of Scientific and Technical Information of China (English)

    Fu Xin; Yang Huayong

    2000-01-01

    In order to improve the engineering performance of a novel hydraulic shock generator,the fluid flow inside its complex passages is numerically investigated.The effects of the inlet flow velocity upon the turbulence intensity of the jet flow are analyzed.The calculated pressure loss is experimentally verified with the consideration of temperature determined viscosity shifting.The results are used as the reference in the further development of the hydraulic shock generator

  15. Hydraulic Arm Modeling via Matlab SimHydraulics

    OpenAIRE

    Věchet, Stanislav; Krejsa, Jiří

    2009-01-01

    System modeling is a vital tool for cost reduction and design process speed up in most engineering fields. The paper is focused on modeling of hydraulic arm as a part of intelligent prosthesis project, in the form of 2DOF open kinematic chain. The arm model combines mechanical, hydraulic and electric subsystems and uses Matlab as modeling tool. SimMechanics Matlab extension is used for mechanical part modeling, SimHydraulics toolbox is used for modeling of hydraulic circuit used for actuating...

  16. HYDRAULICS, TUSCARAWAS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic procedures for estimating flood discharges for a flood insurance...

  17. Hydraulic hoist-press

    Energy Technology Data Exchange (ETDEWEB)

    Babayev, Z.B.; Abashev, Z.V.

    1982-01-01

    The efficiency expert of the Angrenskiy production-technological administration of the production association Sredazugol A. V. Bubnov has suggested a hydraulic hoist-press for repairing road equipment which is a device consisting of lifting mechanism, press and test stand for verifying the high pressure hoses and pumps.

  18. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  19. Water Treatment Technology - Hydraulics.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  20. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on-going...

  1. Numerical Analysis of Pelton Nozzle Jet Flow Behavior Considering Elbow Pipe

    Science.gov (United States)

    Chongji, Zeng; Yexiang, Xiao; Wei, Xu; Tao, Wu; Jin, Zhang; Zhengwei, Wang; Yongyao, Luo

    2016-11-01

    In Pelton turbine, the dispersion of cylindrical jet have a great influence on the energy interaction of jet and buckets. This paper simulated the internal flow of nozzle and the downstream free jet flow at 3 different needle strokes. The nozzle model consists of the elbow pipe and the needle rod which supported by 4 ribs. Homogenous model and SST k-ω model were adopted to simulate the unsteady two-phase jet flow. The development of free flow, including a contraction process followed by an expansion process, was analysed detailed as well as the influence of the nozzle geometry on the jet flow pattern. The increase of nozzle opening results in a more dispersion jet, which means a higher hydraulic loss. Upstream bend and ribs induce the secondary flow in the jet and decrease the jet concentration.

  2. 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.

  3. AERATION EFFECT OF SUBMERGED JET ON HYDRAULIC CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A water-air two-phase turbulence mathematical model was proposed, The mass-weighted average was adoptedfor velocity, air mass fraction and turbulent parameters. Thealgebraic stress equation was used to calculate the Reynoldsstress. The pulsating flux of air mass fraction was simulatedby employing the concept of the eddy viscosity. The numericalsimulation of aerated flow in plunge pool shows that, for the same depth, aeration may decrease the time-averaged pressureon pool floor and increase slightly the turbulent intensity. Thecomputed concentration and pressure distributions coincidewith the experimental data.

  4. Editorial on Future Jet Technologies

    Science.gov (United States)

    Gal-Or, Benjamin

    2014-12-01

    The jet engine is the prime flight controller in post-stall flight domains where conventional flight control fails, or when the engine prevents catastrophes in training, combat, loss of all airframe hydraulics (the engine retains its own hydraulics), loss of one engine, pilot errors, icing on the wings, landing gear and runway issues in takeoff and landing and in bad-whether recoveries. The scientific term for this revolutionary technology is "jet-steering", and in engineering practice - "thrust vectoring", or "TV". Jet-Steering in advanced fighter aircraft designs is integrated with stealth technology. The resulting classified Thrust-Vectoring-Stealth ("TVS") technology has generated a second jet-revolution by which all Air-&-Sea-Propulsion Science and R&D are now being reassessed. Classified F-22, X-47B/C and RQ-180 TVS-vehicles stand at the front of this revolution. But recent transfers of such sensitive technologies to South Korea and Japan [1-5], have raised various fundamental issues that are evaluated by this editorial-review. One, and perhaps a key conclusion presented here, means that both South Korea and Japan may have missed one of their air-&-sea defenses: To develop and field low-cost unmanned fleets of jet-drones, some for use with expensive, TVS-fighter aircraft in highly congested areas. In turn, the U.S., EU, Russia and China, are currently developing such fleets at various TVS levels and sizes. China, for instance, operates at least 15,000 drones ("UAVs") by 2014 in the civilian sector alone. All Chinese drones have been developed by at least 230 developers/manufacturers [1-16]. Mobile telecommunication of safe links between flyers and combat drones ("UCAVs") at increasingly deep penetrations into remote, congested areas, can gradually be purchased-developed-deployed and then operated by extant cader of tens of thousands "National Champion Flyers" who have already mastered the operation of mini-drones in free-to-all sport clubs under national

  5. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  6. HYDRAULIC ELEVATOR INSTALLATION ESTIMATION FOR THE WATER SOURCE WELL SAND-PACK CLEANING UP

    Directory of Open Access Journals (Sweden)

    V. V. Ivashechkin

    2016-01-01

    Full Text Available The article offers design of a hydraulic elevator installation for cleaning up water-source wells of sand packs. It considerers the installation hydraulic circuit according to which the normal pump feeds the high-level tank water into the borehole through two parallel water lines. The water-jet line with washing nozzle for destroying the sand-pack and the supply pipe-line coupled with the operational nozzle of the hydraulic elevator containing the inlet and the supply pipelines for respectively intaking the hydromixture and removing it from the well. The paper adduces equations for fluid motion in the supply and the water-jet pipelines and offers expressions for evaluating the required heads in them. For determining water flow in the supply and the water-jet pipe lines the author proposes to employ graphical approach allowing finding the regime point in Q–H chart by means of building characteristics of the pump and the pipe-lines. For calculating the useful vertical head, supply and dimensions of the hydraulic elevator the article employs the equation of motion quantity with consistency admission of the motion quantity before and after mixing the flows in the hydraulic elevator. The suggested correlations for evaluating the hydraulic elevator efficiency determine the sand pack removal duration as function of its sizes and the ejected fluid flow rate. A hydraulic-elevator installation parameters estimation example illustrates removing a sand pack from a water-source borehole of 41 m deep and 150 mm diameter bored in the village of Uzla of Myadelsk region, of Minsk oblast. The working efficiency of a manufactured and laboratory tested engineering prototype of the hydraulic elevator installation was acknowledged in actual tests at the indicated borehole site. With application of graphical approach, the suggested for the hydraulic elevator installation parameters calculation procedure allows selecting, with given depth and the borehole diameter

  7. Remotely Adjustable Hydraulic Pump

    Science.gov (United States)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  8. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  9. 高速液压弹射实验装置中高速液压缸的设计%Design of a high speed hydraulic cylinder in a hydraulic catapult system

    Institute of Scientific and Technical Information of China (English)

    陶小军; 李晓明; 朱祖超

    2006-01-01

    本文根据液压缸压杆稳定性计算理论及同步性,确定了高速液压缸的主要尺寸,并对同步性进行了验算;根据高速运动的特点,设计了一种高速密封结构,最后对设计结构进行仿真.校核和仿真结果表明,这种同步液压缸设计是合理可行的.

  10. 铁板小车弹射液压系统的设计与分析%Design and Analysis of Hydraulic System for Iron Plate Vehicle Catapult Hydraulic System

    Institute of Scientific and Technical Information of China (English)

    王文云

    2016-01-01

    在某型水中兵器电磁引信陆上试验中,针对短距离将大质量铁板加速至高速的需求,提出铁板小车液压弹射的方法,详细阐述了铁板小车弹射液压系统的设计思路、液压系统工作原理.此研究成果已应用于实际,效果很好,同时也为其他的高速弹射系统提供了良好的设计思路.

  11. 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.

  12. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    OpenAIRE

    HUANG, Ye; Liu, Changsheng; Shiongur Bamed

    2014-01-01

    Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under...

  13. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2014-09-01

    Full Text Available Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under light loads and wearing of the variable-displacement pump. To overcome these shortcomings, this article designs a closed hydraulic control system in which an AC servo motor drives a quantitative pump that controls a spiral swinging hydraulic cylinder, and analyzes and calculates the structure and parameters of a spiral swinging hydraulic cylinder. The hydraulic system adjusts the servo motor’s speed according to the requirements of the control system, and the motor power matches the power provided to components, thus eliminating the throttling loss of hydraulic circuits. The system is compact, produces a large output force, provides stable transmission, has a quick response, and is suitable as a hydraulic control system of a large butterfly valve.

  14. Jet grouting for a groundwater cutoff wall in difficult glacial soil deposits

    Energy Technology Data Exchange (ETDEWEB)

    Flanagan, R.F.; Pepe, F. Jr. [Parsons Brinckerhoff Quade & Douglas, New York, NY (United States)

    1997-12-31

    Jet grouting is being used as part of a groundwater cutoff wall system in a major New York City subway construction project to limit drawdowns in an adjacent PCB contamination plume. A circular test shaft of jet grout columns was conducted during the design phase to obtain wall installation parameters. The test program also included shaft wall mapping, and measurements of; inflows, piezometric levels, ground heave and temperature, and jet grout hydraulic conductivity. An axisymmetric finite element method groundwater model was established to back calculate the in-situ hydraulic conductivities of both the surrounding glacial soils and the jet grout walls by matching observed inflows and piezometric levels. The model also verified the use of packer permeability test as a tool in the field to evaluate the hydraulic conductivities of jet grout columns. Both the test program and analytic studies indicated that adjustments to the construction procedures would be required to obtain lower hydraulic conductivities of the jet grout walls for construction. A comparison is made with the conductivities estimated from the test program/analytic studies with those from the present construction.

  15. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...... of the laws of physics on the system. The unknown (or uncertain) parameters are estimated with Maximum Likelihood (ML) parameter estimation. The identified model has been evaluated by comparing the measurements with simulation of the model. The identified model was much more capable of describing the dynamics...... of the system than the deterministic model....

  16. Modeling of Carrier-based Aircraft's Catapult Launch under Surf%有浪条件下舰载机弹射起飞建模研究

    Institute of Scientific and Technical Information of China (English)

    张磊; 王海峰; 宋笔锋

    2012-01-01

    有浪条件下,航空母舰的摇摆会影响舰载机的安全起飞.对有浪条件下舰载机弹射起飞过程受力、运动情况进行了分析.采用柔性起落架来实现航空母舰与舰载机之间的干涉,建立了模块化的仿真系统并研究了中等海况下航空母舰的摇摆对舰载机弹射起飞的影响.仿真结果表明,中等海况下纵摇是导致下沉的主要因素,最大下沉量可达15 m;横摇导致最大下沉约0.2m;垂荡导致最大下沉约1m;横摇会导致明显的横侧向运动;纵摇、横摇、垂荡均会导致起落架最大载荷显著增大.%The carrier' s swing can endanger the safety of carrier-based aircraft launching. The forces and motions during the carrier-based aircraft catapult launch under surf, adopted flexible gear model to achieve interaction between the carrier-based aircraft and the carrier are theoretically analyzed, founded a modularized simulation system and researched on the influence of carrier' s rocking on aircraft' s catapult launch. Simulation results show that under moderate sea conditions, the pitch is the main factor leading to the subsidence which can up to 15 meters while roll resulting about 0.2 m and heave resulting about 1 m in the maximum subsidence. Roll also leads to significant lateral movement. Pitch, roll and heave result are significantly increased in load of gear.

  17. 舰载机蒸汽弹射热力学仿真分析%The thermodynamic simulation and analysis of the aircraft steam catapults

    Institute of Scientific and Technical Information of China (English)

    梁傲; 陈辉; 张国磊; 郭家敏; 周科; 杨诚

    2016-01-01

    通过对蒸汽弹射器基本工作原理的了解,运用动力学与热力学知识对其进行分析,考虑风速和开槽汽缸导热及漏气对弹射的影响,在合理的假设前提下利用Matlab/Simulink仿真软件建立出了蒸汽弹射热力学动态仿真模型,并以美国C-13型蒸汽弹射器为对象进行仿真分析,得出弹射过程中舰载机的加速度、速度、位移和储汽筒和汽缸内压力、温度以及漏汽量及耗汽量等参数的变化规律,对进一步了解蒸汽弹射具有一定意义。%The paper using the knowledge of dynamics and thermodynamics and the understanding of the basic prin-ciple of steam catapult, developing an analysis on the steam ejection of carrier-based aircraft, which is considering the thermal conductivity, the wind speed and the cylinder leakage effects on ejection;furthermore, a thermodynamic steam cata-pult out of a dynamic simulation model is established under the reasonable assumptions of the use of Matlab/Simulink simu-lation software. Meanwhile, a simulation analysis on C-13 type steam ejection of America shows that the acceleration, the velocity, the displacement, the steam reservoir, the inner pressure of the cylinder, the temperature, the quantity of the steam leakage and the steam consumption etc. and such kind changing rule of parameters, which are of great significance to have a further understanding of the steam ejection.

  18. 舰载机弹射起飞动力学虚拟试验研究%Research on Dynamics during Catapult Takeoff of Carrier-based Aircraft

    Institute of Scientific and Technical Information of China (English)

    隋成国; 许锋; 聂宏

    2013-01-01

    基于多体动力软件LMS Virtual.lab建立了某型飞机弹射起飞的刚柔耦合虚拟样机模型,使用一对点和柔性曲线约束副来模拟活塞杆和外筒的运动,分析了目标飞机的弹射起飞安全性及弹射过程中飞机的动力学响应.仿真表明:目标飞机的舰首下沉量能够满求,可以安全起飞.纵摇和垂荡的耦合会使飞机舰首下沉量增大;分离时的动态响应情况与分离载荷的大小和衰减速度有关.%A flex-rigid virtual prototype model was built in LMS Virtual, lab to simulate the catapult launch process of carrier-based aircraft. A pair of flex point curve joints were used to simulate the movements of the piston rod and the outer tube. The catapult security and dynamics response of the target aircraft were analyzed. Simulation results show that: the target aircraft meets the criteria requirements,and can take off safelysthe coupling of pitch and heave will increase subsidence;the dynamic response caused by separation is related to the size and decay rate of separate load.

  19. 46 CFR 28.880 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... hydraulic equipment and the adjacent work area. Protection shall be afforded to the operator of hydraulic... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.880 Section 28.880 Shipping... INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.880 Hydraulic equipment. (a) Each hydraulic system must...

  20. 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.

  1. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif

    2014-01-01

    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  2. Hydraulic rams; a comparative investigation

    NARCIS (Netherlands)

    Tacke, J.H.P.M.

    1988-01-01

    A mathematical model describing the essential features of hydraulic ram operation is developed in order to clarify the possibilities and limitations of the ram relative to its site and its adjustments. The model distinguishes three different periods in the pumping cycle of the hydraulic ram: acceler

  3. Hydraulics. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on hydraulics is one of a series of power mechanics texts and visual aids for training in the servicing of agricultural and industrial machinery. Focus is on oil hydraulics. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The twelve chapters focus…

  4. Research on hydraulic slotting technology controlling coal-gas outbursts

    Institute of Scientific and Technical Information of China (English)

    WEI Guo-ying; SHAN Zhi-yong; ZHANG Zi-min

    2008-01-01

    Measured to control serious coal-gas outburst in coal seam were analyzed by theory and experimented in test site. A new technique to distress the coal-bed and drain methane, called hydraulic slotting, was described in detail, and the mechanism of hydrau-lic slotting was put forward and analyzed. The characteristic parameter of hydraulic slotting was given in Jiaozuo mining area and the characteristic of validity, adaptability and secu-rity was evaluated. The results show that the stress surrounding the strata and the gas in coal seam is released efficiently and thoroughly while new techniques are taken, as slot-ting at heading face by high pressure large diameter jet. The resistance to coal and gas outbursts is increased dramatically once the area of slotting is increased to a certain size.In the process of driving 2 000 m tunnel by hydraulic slotting excavation, coal and gas outburst never occurre. The technique could be used to prevent and control potential coal-gas outburst in the proceeding of tunnel driving, and the speed tunneling could be as high as more than 2 times.

  5. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  6. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  7. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

    As wind turbines increase in size, combined with increased lifetime demands, new methods for load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and hereby dampen the loads to the system, which is the focus of the current paper. By utilizing...... the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in critical components. Results shows that a significant reduction in fatigue and extreme loads to the yaw...... system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct...

  8. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

    Hansen, M. R.; Andersen, T. O.; Nielsen, B.

    2003-01-01

    system for agricultural applications and driving for transportation. During tranport phases, the lack of suspension causes the vehicle to bounce and pitch, and makes it difficalt to control. Many systems have been proposed to cope with the oscillatory behavior, and different solutions exist. Common......This paper present and discusses R&D results on electro hydraulic hitch control for off-road vehicle, in particular active damping of oscillation occuring on tractors. The research deals with analysis and control of the oscillations occuring on tractors which are design without any susspection...... for most of the systems are that they operate on the hydrailc actuators generally providing the motive forces for moving the implement and/or attachment, typically a plough. The basic idea and physical working principle are to use the implement, moveable relative to the vehicle, as a damper mass. The paper...

  9. Jet substructure in ATLAS

    CERN Document Server

    Miller, David W

    2011-01-01

    Measurements are presented of the jet invariant mass and substructure in proton-proton collisions at $\\sqrt{s} = 7$ TeV with the ATLAS detector using an integrated luminosity of 37 pb$^{-1}$. These results exercise the tools for distinguishing the signatures of new boosted massive particles in the hadronic final state. Two "fat" jet algorithms are used, along with the filtering jet grooming technique that was pioneered in ATLAS. New jet substructure observables are compared for the first time to data at the LHC. Finally, a sample of candidate boosted top quark events collected in the 2010 data is analyzed in detail for the jet substructure properties of hadronic "top-jets" in the final state. These measurements demonstrate not only our excellent understanding of QCD in a new energy regime but open the path to using complex jet substructure observables in the search for new physics.

  10. 运输类飞机弹射起飞动力学特性分析%Analysis of dynamical characteristics for transport catapult-assisted take-off

    Institute of Scientific and Technical Information of China (English)

    杨生民; 刘超; 刘智汉

    2011-01-01

    根据运输类飞机弹射起飞特点,建立了运输类飞机、舰船和风场等数学模型,着重介绍了能够反映飞机和舰船间多体动力学关系的起落架模型、弹射器和舰船运动模型的建模方法;开展了运输类飞机弹射起飞动力学特性研究,重点分析了起飞重量、升降舵预置偏度、甲板运动、前起落架突伸等因素对弹射起飞的影响,以期为运输类舰载机的设计和飞行试验提供技术支持.%Based on dynamical characteristics of transport catapult-assisted take-off, several models of carrier-type transports, and their near zones between a carrier and wind fields are designed in this paper. It mainly introduces the modeling method of different models for landing gears, a catapult and carrier motions to be able to represent the multi-body dynamical relevance between aircraft and carrier, and discusses dynamical characteristics for the transport catapult-assisted take-off. It is focus on analyzing the effects of various factors, including the transport ' s take-off weight, elevator predefined deflections, deck motions and nose gear sudden extension on the catapult-assisted take-off. The simulation results will give a reference to design and flight test for carrier-type transports.

  11. Review of literature on local scour under plane turbulent wall jets

    Science.gov (United States)

    Aamir, Mohammad; Ahmad, Zulfequar

    2016-10-01

    Stability of hydraulic structures is threatened by persistent scour downstream of the apron, which renders their foundations exposed. Jets issuing under the sluice gate are turbulent enough to cause significant scour. Extensive study of the jets is, therefore, necessary in order to understand the underlying hydraulics and provide remedial measures. In this paper, a comprehensive review of the investigations on local scour caused by wall jets is presented, including both the classical as well as the prevalent approach. Various aspects of the scour under wall jets have been explained, including the process of scouring, different parameters affecting the maximum scour depth, analysis of flow characteristics within the scour hole and on the apron, time variation of scour depth, rate of sediment removal, and scour depth estimation formulae.

  12. Hydraulic conductivity of compacted zeolites.

    Science.gov (United States)

    Oren, A Hakan; Ozdamar, Tuğçe

    2013-06-01

    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  13. HYDRODYNAMIC ANALYSIS OF SUCK-IN PULSED JET IN WELL DRILLING

    Institute of Scientific and Technical Information of China (English)

    WANG Rui-he; DU Yu-kun; NI Hong-jian; MA Lin

    2011-01-01

    The development of new drilling methods is important for the exploration and production of oil fields. The pulsed jet is a drilling technology of high potentiality. This article proposes a new concept of suck-in pulsed jet with self-excited oscillation, by which a full use of the hydraulic power can be made in the annular space. A hydrodynamic analysis of suck-in pulsed jet with self-excited oscillation is carried out by numerical simulations and rock-breaking experiments. It is shown that with the jet, a negative pressure zone will be formed in the oscillation cavity to ensure automatic sucking of enough annular fluids and the formation of an efficient pulsed jet. The rock-breaking and pressure testing results have verified the reliability of the numerical simulation. The research provides a basis for the development of the pulsed jet drilling technology.

  14. Numerical simulation of slurry jets using mixture model

    Directory of Open Access Journals (Sweden)

    Wen-xin HUAI

    2013-01-01

    Full Text Available Slurry jets in a static uniform environment were simulated with a two-phase mixture model in which flow-particle interactions were considered. A standard k-ε turbulence model was chosen to close the governing equations. The computational results were in agreement with previous laboratory measurements. The characteristics of the two-phase flow field and the influences of hydraulic and geometric parameters on the distribution of the slurry jets were analyzed on the basis of the computational results. The calculated results reveal that if the initial velocity of the slurry jet is high, the jet spreads less in the radial direction. When the slurry jet is less influenced by the ambient fluid (when the Stokes number St is relatively large, the turbulent kinetic energy k and turbulent dissipation rate ε, which are relatively concentrated around the jet axis, decrease more rapidly after the slurry jet passes through the nozzle. For different values of St, the radial distributions of streamwise velocity and particle volume fraction are both self-similar and fit a Gaussian profile after the slurry jet fully develops. The decay rate of the particle velocity is lower than that of water velocity along the jet axis, and the axial distributions of the centerline particle streamwise velocity are self-similar along the jet axis. The pattern of particle dispersion depends on the Stokes number St. When St = 0.39, the particle dispersion along the radial direction is considerable, and the relative velocity is very low due to the low dynamic response time. When St = 3.08, the dispersion of particles along the radial direction is very little, and most of the particles have high relative velocities along the streamwise direction.

  15. Turbulent buoyant jets and plumes

    CERN Document Server

    Rodi, Wolfgang

    The Science & Applications of Heat and Mass Transfer: Reports, Reviews, & Computer Programs, Volume 6: Turbulent Buoyant Jets and Plumes focuses on the formation, properties, characteristics, and reactions of turbulent jets and plumes. The selection first offers information on the mechanics of turbulent buoyant jets and plumes and turbulent buoyant jets in shallow fluid layers. Discussions focus on submerged buoyant jets into shallow fluid, horizontal surface or interface jets into shallow layers, fundamental considerations, and turbulent buoyant jets (forced plumes). The manuscript then exami

  16. Hydraulic Actuators with Autonomous Hydraulic Supply for the Mainline Aircrafts

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2014-01-01

    Full Text Available Applied in the aircraft control systems, hydraulic servo actuators with autonomous hydraulic supply, so-called, hydraulic actuators of integrated configuration, i.e. combination of a source of hydraulic power and its load in the single unit, are aimed at increasing control system reliability both owing to elimination of the pipelines connecting the actuator to the hydraulic supply source, and owing to avoidance of influence of other loads failure on the actuator operability. Their purpose is also to raise control system survivability by eliminating the long pipeline communications and their replacing for the electro-conductive power supply system, thus reducing the vulnerability of systems. The main reason for a delayed application of the hydraulic actuators in the cutting-edge aircrafts was that such aircrafts require hydraulic actuators of considerably higher power with considerable heat releases, which caused an unacceptable overheat of the hydraulic actuators. Positive and negative sides of the hydraulic actuators, their alternative options of increased reliability and survivability, local hydraulic systems as an advanced alternative to independent hydraulic actuators are considered.Now to use hydraulic actuators in mainline aircrafts is inexpedient since there are the unfairly large number of the problems reducing, first and last, safety of flights, with no essential weight and operational advantages. Still works to create competitive hydraulic actuators ought to be continued.Application of local hydraulic systems (LHS will allow us to reduce length of pressure head and drain pipelines and mass of pipelines, as well as to raise their general fail-safety and survivability. Application of the LHS principle will allow us to use a majority of steering drive advantages. It is necessary to allocate especially the following:- ease of meeting requirements for the non-local spread of the engine weight;- essentially reducing length and weight of

  17. Hydraulic conductivity of organomodified soil

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, R.B.; Grant, J.M.; Voice, T.C.; Rakhshandehroo, G.; Xu, S.; Boyd, S.A. [Michigan State Univ., East Lansing, MI (United States)

    1995-11-01

    The effects of organomodification on soil hydraulic conductivity were investigated. Hydraulic conductivity and porosity of treated and untreated samples of a sandy loam were measured as a function of effective stress. Batch treatment with hexadecyltrimethyl ammonium (HDTMA) and dry packing produced organomodified samples that were 79% less conducive than untreated samples prior to loading. Treated samples lost less hydraulic conductivity as a result of loading than untreated samples so that treated samples had higher conductivity at high loads. Observed differences in conductivity are explained in terms of the role of the treated and untreated clay in controlling initial effective pore size and its change during consolidation.

  18. Jet Substructure Without Trees

    Energy Technology Data Exchange (ETDEWEB)

    Jankowiak, Martin; Larkoski, Andrew J.; /SLAC /Stanford U., ITP

    2011-08-19

    We present an alternative approach to identifying and characterizing jet substructure. An angular correlation function is introduced that can be used to extract angular and mass scales within a jet without reference to a clustering algorithm. This procedure gives rise to a number of useful jet observables. As an application, we construct a top quark tagging algorithm that is competitive with existing methods. In preparation for the LHC, the past several years have seen extensive work on various aspects of collider searches. With the excellent resolution of the ATLAS and CMS detectors as a catalyst, one area that has undergone significant development is jet substructure physics. The use of jet substructure techniques, which probe the fine-grained details of how energy is distributed in jets, has two broad goals. First, measuring more than just the bulk properties of jets allows for additional probes of QCD. For example, jet substructure measurements can be compared against precision perturbative QCD calculations or used to tune Monte Carlo event generators. Second, jet substructure allows for additional handles in event discrimination. These handles could play an important role at the LHC in discriminating between signal and background events in a wide variety of particle searches. For example, Monte Carlo studies indicate that jet substructure techniques allow for efficient reconstruction of boosted heavy objects such as the W{sup {+-}} and Z{sup 0} gauge bosons, the top quark, and the Higgs boson.

  19. 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.

  20. HYDRAULICS, ATHENS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  1. HYDRAULICS, JACKSON COUNTY, KENTUCKY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  2. HYDRAULICS, MADISON COUNTY, ALABAMA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Hydraulic data was reviewed and approved by FEMA during the initial MT-2 processing. Recent developments in digital terrain and geospatial database management...

  3. HYDRAULICS, HAMPDEN COUNTY, MA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data in this submittal include spatial datasets and model outputs necessary for computation of the 1-percent flooding extent. The minimum requirement for...

  4. Hydraulic wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The purpose of this research was to design, build and test a hydraulic wind energy system. This design used a three bladed turbine, which drove a hydraulic pump. The energy is transmitted from the pump through a long hose and into a hydraulic motor, where the energy is used. This wind system was built and tested during the winter of 1980-1981. The power train included a five meter, three bladed wind turbine, a 9.8:1 ratio gearbox, a 1.44 cubic inch displacement pump with a small supercharge gear pump attached. The hydraulic fluid was pumped through a 70', 3/4'' I-D-high pressure flexhose, then through a volume control valve and into a 1.44 cubic inch displacement motor. The fluid was returned through a 70', 1'' I-D-flexhose.

  5. 14 CFR 29.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 29.1435 Section 29.1435... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each element of the hydraulic system...

  6. 14 CFR 23.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 23.1435 Section 23.1435... § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each hydraulic system and its elements must withstand, without yielding, the structural loads expected...

  7. 46 CFR 28.405 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.405 Section 28.405 Shipping... Operate With More Than 16 Individuals on Board § 28.405 Hydraulic equipment. (a) Each hydraulic system... than four times the system maximum operating pressure. (c) Each hydraulic system must be equipped...

  8. 偏中心定位对弹射过程中飞机姿态的影响%Effects of off-center location on aircraft attitude during catapult launch

    Institute of Scientific and Technical Information of China (English)

    于浩; 聂宏

    2011-01-01

    Owing to the deck motion and some other factors, the aircraft often has off-center distance with the catapult orbit. To study with this phenomenon, considering the deck motion, landing gear cushion and flexible tires, a six-degree-of-freedom mathematic model of carrier-based aircraft off-center catapult launch was established. The aircraft attitude during catapult taxing affected by the off-center distance with typical deck motion was studied. From the off-center catapult launch calculation, three important conclusions were obtained. The yaw movement are affected clearly by the initial off-center distance and its amplitude increases with the increase of the initial off-center distance. The attenuation of the yaw movement is clearly during catapult taxing and the launch bar side bending moment increases with the increase of the initial off-center distance. The results provide theoretical foundation for carrier-based aircraft design.%舰载飞机弹射起飞时,由于航母运动等因素的影响,飞机往往无法与弹射轨道对中.针对这种情况,在考虑航母运动以及起落架缓冲和轮胎弹性的基础上,建立六自由度偏中心定位弹射起飞数学模型,研究了在航母典型运动状态下不同初始偏心距离对弹射起飞过程中飞机姿态的影响,结果表明:初始偏心距离对飞机的偏航运动影响最大,偏航运动的幅度随初始偏心距离的增大而增大;在弹射滑跑过程中,飞机的偏航运动有明显的衰减趋势;弹射杆所承受的侧向弯矩随初始偏心距离的增大而增大.研究结果为舰载飞机的设计提供了一定的理论参考.

  9. TASI Lectures on Jet Substructure

    CERN Document Server

    Shelton, Jessie

    2013-01-01

    Jet physics is a rich and rapidly evolving field, with many applications to physics in and beyond the Standard Model. These notes, based on lectures delivered at the June 2012 Theoretical Advanced Study Institute, provide an introduction to jets at the Large Hadron Collider. Topics covered include sequential jet algorithms, jet shapes, jet grooming, and boosted Higgs and top tagging.

  10. Jet propagation and deceleration

    CERN Document Server

    Perucho, Manel

    2013-01-01

    Extragalactic jets in active galactic nuclei (AGN) are divided into two morphological types, namely Fanaroff-Riley I (FRI) and Fanaroff-Riley II (FRII). The former show decollimated structure at the kiloparsec scales and are thought to be decelerated by entrainment within the first kiloparsecs of evolution inside the host galaxy. The entrainment and deceleration can be, at least partly, due to the interaction of jets with stellar winds and gas clouds that enter in the jet as they orbit around the galactic centre. In this contribution, I review recent simulations to study the dynamic effect of entrainment from stellar winds in jets and the direct interaction of jets with gas clouds and stellar winds. I also briefly describe the importance of these interactions as a possible scenario of high-energy emission from extragalactic jets.

  11. What ignites optical jets?

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian Jester

    2002-12-23

    The properties of radio galaxies and quasars with and without optical or X-ray jets are compared. The majority of jets from which high-frequency emission has been detected so far (13 with optical emission, 11 with X-rays, 13 with both) are associated with the most powerful radio sources at any given redshift. It is found that optical/X-ray jet sources are more strongly beamed than the average population of extragalactic radio sources. This suggests that the detection or non-detection of optical emission from jets has so far been dominated by surface brightness selection effects, not by jet physics. It implies that optical jets are much more common than is currently appreciated.

  12. Mini-Jet Controlled Turbulent Round Air Jet

    Institute of Scientific and Technical Information of China (English)

    杜诚; 米建春; 周裕; 詹杰

    2011-01-01

    We report an investigation of the active control of a round air jet by multiple radial blowing mini-jets.The Reynolds number based on the jet exit velocity and diameter is 8000.It is found that once the continuous minijets are replaced with pulsed ones,the centerline velocity decay rate K can be greatly increased as the pulsing frequency of mini-jets approaches the natural vortex frequency of the main jet.For example,the K value is amplified by more than 50% with two(or four)pulsed mini-jets blowing,compared with the continuous mini-jets at the same ratio of the mass flow rate of the mini-jets to that of the main jet.%We report an investigation of the active control of a round air jet by multiple radial blowing mini-jets. The Reynolds number based on the jet exit velocity and diameter is 8000. It is found that once the continuous mini-jets are replaced with pulsed ones, the centerline velocity decay rate K can be greatly increased as the pulsing frequency of mini-jets approaches the natural vortex frequency of the main jet. For example, the K value is amplified by more than 50% with two (or four) pulsed mini-jets blowing, compared with the continuous mini-jets at the same ratio of the mass Sow rate of the mini-jets to that of the main jet.

  13. Hotspots, Jets and Environments

    Science.gov (United States)

    Hardcastle, M. J.

    2008-06-01

    I discuss the nature of `hotspots' and `jet knots' in the kpc-scale structures of powerful radio galaxies and their relationship to jet-environment interactions. I describe evidence for interaction between the jets of FRI sources and their local environments, and discuss its relationship to particle acceleration, but the main focus of the paper is the hotspots of FRIIs and on new observational evidence on the nature of the particle acceleration associated with them.

  14. 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

  15. Properties of gluon jets

    Energy Technology Data Exchange (ETDEWEB)

    Sugano, K.

    1986-09-01

    The properties of gluon jets are reviewed from an experimental point of view. The measured characteristics are compared to theoretical expectations. Although neither data nor models for the gluon jets are in the mature stage, there are remarkable agreements and also intriguing disagreements between experiment and theory. Since much interesting data have begun to emerge from various experiments and the properties of gluon jets are deeply rooted in the basic structure of non-Abelian gauge theory, the study of gluon jets casts further light on our understanding of QCD. Finally, the future prospects are discussed.

  16. The hydrogen laminar jet

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Sanz, M. [Departamento de Motopropulsion y Termofluidomecanica, ETSI Aeronauticos, Universidad Politecnica de Madrid, 28040 Madrid (Spain); Rosales, M. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain); Instituto de Innovacion en Mineria y Metalurgia, Avenida del Valle 738, Santiago (Chile); Sanchez, A.L. [Department Ingenieria Termica y de Fluidos, Universidad Carlos III de Madrid, 28911, Leganes (Spain)

    2010-04-15

    Numerical and asymptotic methods are used to investigate the structure of the hydrogen jet discharging into a quiescent air atmosphere. The analysis accounts in particular for the variation of the density and transport properties with composition. The Reynolds number of the flow R{sub j}, based on the initial jet radius a, the density {rho}{sub j} and viscosity {mu}{sub j} of the jet and the characteristic jet velocity u{sub j}, is assumed to take moderately large values, so that the jet remains slender and stable, and can be correspondingly described by numerical integration of the continuity, momentum and species conservation equations written in the boundary-layer approximation. The solution for the velocity and composition in the jet development region of planar and round jets, corresponding to streamwise distances of order R{sub j}a, is computed numerically, along with the solutions that emerge both in the near field and in the far field. The small value of the hydrogen-to-air molecular weight ratio is used to simplify the solution by considering the asymptotic limit of vanishing jet density. The development provides at leading-order explicit analytical expressions for the far-field velocity and hydrogen mass fraction that describe accurately the hydrogen jet near the axis. The information provided can be useful in particular to characterize hydrogen discharge processes from holes and cracks. (author)

  17. Technologies and Innovations for Hydraulic Pumps

    OpenAIRE

    Ivantysynova, Monika

    2016-01-01

    Positive displacement machines working as hydraulic pumps or hydraulic motors have always been, are and will be an essential part of any hydraulic system. Current trends and future demands on energy efficient systems will not only drastically increase the number of positive displacement machines needed for modern efficient hydraulic circuits but will significantly change the performance requirements of pumps and motors. Throttleless system configurations will change the landscape of hydraulic...

  18. Prospects for application of robotic mechano-hydraulical excavation of gas-bearing coal layers at great depths

    Science.gov (United States)

    Fryanov, V. N.; Pavlova, L. D.

    2016-10-01

    In the paper the scientific basis for robotic technology of excavation prone to gas- dynamic phenomena of a coal layer with high gas-bearing capacity at great depths is developed. The constructive scheme of automated remote-controlled mining robot, that fractures coal by high-pressure hydraulic jets in the gas polluted environment, is proposed.

  19. Jet mass spectra in Higgs+one jet at NNLL

    Energy Technology Data Exchange (ETDEWEB)

    Jouttenus, Teppo T.; Stewart, Iain W. [Massachusetts Institute of Technology, Cambridge, MA (United States). Center for Theoretical Physics; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Waalewijn, Wouter J. [California Univ., San Diego, La Jolla, CA (United States). Dept. of Physics

    2013-02-15

    The invariant mass of a jet is a benchmark variable describing the structure of jets at the LHC. We calculate the jet mass spectrum for Higgs plus one jet at the LHC at next-to-next-to-leading logarithmic (NNLL) order using a factorization formula. At this order, the cross section becomes sensitive to perturbation theory at the soft m{sup 2}{sub jet}/p{sup jet}{sub T} scale. Our calculation is exclusive and uses the 1-jettiness global event shape to implement a veto on additional jets. The dominant dependence on the jet veto is removed by normalizing the spectrum, leaving residual dependence from non-global logarithms depending on the ratio of the jet mass and jet veto variables. For our exclusive jet cross section these non-global logarithms are parametrically smaller than in the inclusive case, allowing us to obtain a complete NNLL result. Results for the dependence of the jet mass spectrum on the kinematics, jet algorithm, and jet size R are given. Using individual partonic channels we illustrate the difference between the jet mass spectra for quark and gluon jets. We also study the effect of hadronization and underlying event on the jet mass in Pythia. To highlight the similarity of inclusive and exclusive jet mass spectra, a comparison to LHC data is presented.

  20. 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.

  1. EFFECT OF ENLARGED FREE JET ON ENERGY CONVERSION IN PELTON TURBINE

    Institute of Scientific and Technical Information of China (English)

    LIU Jie; WEI Cai-xin; HAN Feng-qin

    2006-01-01

    In Pelton turbines, when the water jet emerges in the air, its velocity decreases downstream and its diameter increases to meet the continuity. In this paper, a physical parameter, the enlarging rate of jet diameter kDj was introduced and measured experimentally. The measurement of enlarging rate was carried out in three model turbines with different distributing Y-branch and nozzle configurations under various operating conditions. The effect of jet enlarging rate on the unsteady water sheet flow in the rotating buckets has not been investigated so far. This paper also presents the comparative numerical analysis of the flow in buckets at different enlarging rates of jet. It is shown that the effect of jet enlargement is so large that the flow pattern in the bucket is drastically changed by the latter half of the frames. The jet with large enlarging rate also introduces worse energy behavior to the hydraulic performance of the Pelton turbine. Besides, the phenomenon of jet interference was also discussed by using the results of numerical simulation for one jet. It indicates that the jet with large enlarging rate takes more risk that jet interference may damage the performance of multi-nozzle Pelton turbine.

  2. 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.

  3. Faraday, Jets, and Sand

    NARCIS (Netherlands)

    Sandtke, M.; van der Meer, Roger M.; Versluis, Andreas Michel; Lohse, Detlef

    2003-01-01

    When a 6-mm layer of fine sand with an average grain size of 40 µm is poured into a cylindrical container and shaken vertically, thin jets are seen to emerge from an airy cloud of grains, almost like protuberances from the corona of the sun. A quasi two-dimensional setup reveals the jet-formation

  4. Jet propulsion without inertia

    CERN Document Server

    Spagnolie, Saverio E

    2010-01-01

    A body immersed in a highly viscous fluid can locomote by drawing in and expelling fluid through pores at its surface. We consider this mechanism of jet propulsion without inertia in the case of spheroidal bodies, and derive both the swimming velocity and the hydrodynamic efficiency. Elementary examples are presented, and exact axisymmetric solutions for spherical, prolate spheroidal, and oblate spheroidal body shapes are provided. In each case, entirely and partially porous (i.e. jetting) surfaces are considered, and the optimal jetting flow profiles at the surface for maximizing the hydrodynamic efficiency are determined computationally. The maximal efficiency which may be achieved by a sphere using such jet propulsion is 12.5%, a significant improvement upon traditional flagella-based means of locomotion at zero Reynolds number. Unlike other swimming mechanisms which rely on the presentation of a small cross section in the direction of motion, the efficiency of a jetting body at low Reynolds number increas...

  5. Complex Fluids and Hydraulic Fracturing.

    Science.gov (United States)

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

    2016-06-07

    Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.

  6. Hydraulic properties of ladle slags

    Directory of Open Access Journals (Sweden)

    J. Vlček

    2016-07-01

    Full Text Available The article presents results of examining of hydraulic properties of ladle slags formed during production of steel. The studied ladle slags were subjected to different cooling mode from the molten state. Based on the ability of the slag react with the water was assessed their hydraulic activity. The hydraulic properties are caused by the presence of minerals dicalcium silicate, tricalcium aluminate, mayenite, brownmillerite and dicalcium ferite. The emergence of required hydrating phases in the ladle slags is conditioned by a sufficient CaO content and their cooling rate. The contact the slag with water during processing and their ageing has a negative effect. The experiment has shown that the phase transformation of the mineral dicalcium silicate which occurs during cooling of the ladle slags cause their volume instability.

  7. Simulations of Solar Jets

    Science.gov (United States)

    Kohler, Susanna

    2017-02-01

    Formation of a coronal jet from twisted field lines that have reconnected with the ambient field. The colors show the radial velocity of the plasma. [Adapted from Szente et al. 2017]How do jets emitted from the Suns surface contribute to its corona and to the solar wind? In a recent study, a team of scientists performed complex three-dimensional simulations of coronal jets to answer these questions.Small ExplosionsCoronal jets are relatively small eruptions from the Suns surface, with heights of roughly 100 to 10,000 km, speeds of 10 to 1,000 km/s, and lifetimes of a few minutes to around ten hours. These jets are constantly present theyre emitted even from the quiet Sun, when activity is otherwise low and weve observed them with a fleet of Sun-watching space telescopes spanning the visible, extreme ultraviolet (EUV), and X-ray wavelength bands.A comparison of simulated observations based on the authors model (left panels) to actual EUV and X-ray observations of jets (right panels). [Szente et al. 2017]Due to their ubiquity, we speculate that these jets might contribute to heating the global solar corona (which is significantly hotter than the surface below it, a curiosity known as the coronal heating problem). We can also wonder what role these jets might play in driving the overall solar wind.Launching a JetLed by Judit Szente (University of Michigan), a team of scientists has explored the impact of coronal jets on the global corona and solar wind with a series of numerical simulations. Szente and collaborators used three-dimensional, magnetohydrodynamic simulations that provide realistic treatment of the solar atmosphere, the solar wind acceleration, and the complexities of heat transfer throughout the corona.In the authors simulations, a jet is initiated as a magnetic dipole rotates at the solar surface, winding up field lines. Magnetic reconnection between the twisted lines and the background field then launches the jet from the dense and hot solar

  8. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.

    2013-02-01

    Biofilms may interfere with membrane performance in at least three ways: (i) increase of the transmembrane pressure drop, (ii) increase of feed channel (feed-concentrate) pressure drop, and (iii) increase of transmembrane passage. Given the relevance of biofouling, it is surprising how few data exist about the hydraulic resistance of biofilms that may affect the transmembrane pressure drop and membrane passage. In this study, biofilms were generated in a lab scale cross flow microfiltration system at two fluxes (20 and 100Lm-2h-1) and constant cross flow (0.1ms-1). As a nutrient source, acetate was added (1.0mgL-1 acetate C) besides a control without nutrient supply. A microfiltration (MF) membrane was chosen because the MF membrane resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric substances (EPS) were determined, it was demonstrated that no internal membrane fouling occurred and that the fouling layer actually consisted of a grown biofilm and was not a filter cake of accumulated bacterial cells. At 20Lm-2h-1 flux with a nutrient dosage of 1mgL-1 acetate C, the resistance after 4 days reached a value of 6×1012m-1. At 100Lm-2h-1 flux under the same conditions, the resistance was 5×1013m-1. No correlation of biofilm resistance to biofilm thickness was found; Biofilms with similar thickness could have different resistance depending on the applied flux. The cell number in biofilms was between 4×107 and 5×108 cellscm-2. At this number, bacterial cells make up less than a half percent of the overall biofilm volume and therefore did not hamper the water flow through the biofilm significantly. A flux of 100Lm-2h-1 with nutrient supply caused higher cell numbers, more biomass, and higher biofilm resistance than a flux of 20Lm-2h-1. However, the biofilm thickness

  9. Controls of Hydraulic Wind Turbine

    Directory of Open Access Journals (Sweden)

    Zhang Yin

    2016-01-01

    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

  10. Impact of hydraulic well restoration on native bacterial communities in drinking water wells.

    Science.gov (United States)

    Karwautz, Clemens; Lueders, Tillmann

    2014-01-01

    The microbial monitoring of drinking water production systems is essential to assure water quality and minimize possible risks. However, the comparative impact of microbes from the surrounding aquifer and of those established within drinking water wells on water parameters remains poorly understood. High pressure jetting is a routine method to impede well clogging by fine sediments and also biofilms. In the present study, bacterial communities were investigated in a drinking water production system before, during, and after hydraulic purging. Variations were observed in bacterial communities between different wells of the same production system before maintenance, despite them having practically identical water chemistries. This may have reflected the distinct usage practices of the different wells, and also local aquifer heterogeneity. Hydraulic jetting of one well preferentially purged a subset of the dominating taxa, including lineages related to Diaphorobacter, Nitrospira, Sphingobium, Ralstonia, Alkanindiges, Janthinobacterium, and Pseudomonas spp, suggesting their tendency for growth in well-associated biofilms. Lineages of potential drinking water concern (i.e. Legionellaceae, Pseudomonadaceae, and Acinetobacter spp.) reacted distinctly to hydraulic jetting. Bacterial diversity was markedly reduced in drinking water 2 weeks after the cleaning procedure. The results of the present study provide a better understanding of drinking water wells as a microbial habitat, as well as their role in the microbiology of drinking water systems.

  11. Integrating hydraulic equivalent sections into a hydraulic geometry study

    Science.gov (United States)

    Jia, Yanhong; Yi, Yujun; Li, Zhiwei; Wang, Zhaoyin; Zheng, Xiangmin

    2017-09-01

    Hydraulic geometry (HG) is an important geomorphic concept that has played an indispensable role in hydrological analyses, physical studies of streams, ecosystem and aquatic habitat studies, and sedimentology research. More than 60 years after Leopold and Maddock (1953) first introduced the concept of HG, researchers have still not uncovered the physical principles underlying HG behavior. One impediment is the complexity of the natural river cross section. The current study presents a new way to simplify the cross section, namely, the hydraulic equivalent section, which is generalized from the cross section in the ;gradually varied flow of an alluvial river; (GVFAR) and features hydrodynamic properties and bed-building laws similar to those of the GVFAR. Energy balance was used to derive the stage Z-discharge Q relationship in the GVFAR. The GVFAR in the Songhua River and the Yangtze River were selected as examples. The data, including measured discharge, river width, water stage, water depth, wet area, and cross section, were collected from the hydrological yearbooks of typical hydrological stations on the Songhua River and the Yangtze River from 1955 to 1987. The relationships between stage Z-discharge Q and cross-sectional area A-stage Z at various stations were analyzed, and ;at-a-station hydraulic geometry; (AHG) relationships were obtained in power-law forms. Based on derived results and observational data analysis, the Z-Q and Z-A relationships of AHG were similar to rectangular weir flows, thus the cross section of the GVFAR was generalized as a compound rectangular, hydraulic equivalent cross section. As to bed-building characteristics, the bankfull discharge method and the stage-discharge-relation method were used to calculate the dominant variables of the alluvial river. This hydraulic equivalent section has the same Z-Q relation, Z-A relation, dominant discharge, dominant river width, and dominant water depth as the cross section in the GVFAR. With the

  12. Jets and QCD

    Energy Technology Data Exchange (ETDEWEB)

    Ali, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Kramer, G. [Hamburg Univ. (Germany). II. Inst. fuer Theoretische Physik

    2010-12-15

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in e{sup +}e{sup -} collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in ep and pp/p anti p collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundamental 2-2 quark/gluon scattering processes, but also the impact of jet decays of top quarks, and W{sup {+-}},Z bosons on the electroweak sector. The presentation to a large extent is formulated in a non-technical language with the intent to recall the significant steps historically and convey the significance of this field also to communities beyond high energy physics. (orig.)

  13. Solar coronal jets

    Science.gov (United States)

    Dobrzyck, D.

    The solar jets were first observed by SOHO instruments (EIT, LASCO, UVCS) during the previous solar minimum. They were small, fast ejections originating from flaring UV bright points within large polar coronal holes. The obtained data provided us with estimates of the jet plasma conditions, dynamics, evolution of the electron temperature and heating rate required to reproduce the observed ionization state. To follow the polar jets through the solar cycle a special SOHO Joint Observing Program (JOP 155) was designed. It involves a number of SOHO instruments (EIT, CDS, UVCS, LASCO) as well as TRACE. The coordinated observations have been carried out since April 2002. The data enabled to identify counterparts of the 1996-1998 solar minimum jets. Their frequency of several events per day appear comparable to the frequency from the previous solar minimum. The jets are believed to be triggered by field line reconnection between emerging magnetic dipole and pre-existing unipolar field. Existing models predict that the hot jet is formed together with another jet of a cool material. The particular goal of the coordinated SOHO and TRACE observations was to look for possible association of the hot and cool plasma ejections. Currently there is observational evidence that supports these models.

  14. Jets with Variable R

    CERN Document Server

    Krohn, David; Wang, Lian-Tao

    2009-01-01

    We introduce a new class of jet algorithms designed to return conical jets with a variable Delta R radius. A specific example, in which Delta R scales as 1/pT, proves particularly useful in capturing the kinematic features of a wide variety of hard scattering processes. We implement this Delta R scaling in a sequential recombination algorithm and test it by reconstructing resonance masses and kinematic endpoints. These test cases show 10-20% improvements in signal efficiency compared to fixed Delta R algorithms. We also comment on cuts useful in reducing continuum jet backgrounds.

  15. Static Balance Analysis of Carrier-Based Aircraft Catapult Launch with Six Degrees of Freedom%舰载机弹射起飞六自由度静平衡分析

    Institute of Scientific and Technical Information of China (English)

    白双刚; 胡孟权; 段进坦

    2012-01-01

    静平衡状态是弹射起飞动力学分析的初始条件,也是进行弹射起飞动力学建模的基础.将舰船、飞机、起落架等视作具有独立质量的多运动实体,并分析描述它们之间的运动耦合关系,建立了舰载机静平衡状态下的六自由度数学模型,考虑了航母运动和甲板风以及海面气流扰动对飞机的影响.利用这一模型仿真计算了在不同情况下舰载机的静平衡状态,并分析了不同情况下舰载机的运动规律.计算结果与实际情况吻合,为舰载机弹射起飞六自由度动力学分析奠定了基础.%Static balance is the initial condition of catapult launch dynamic analysis, and the foundation of establishing the catapult launch model. Carrier, aircraft and landing gears, etc. are considered as multi -motion bodies that have their own masses, and the coupling relationships within these multi - motion bodies are also analyzed. The six degrees of freedom model of carrier - based aircraft is established in the condition of static balance, with the influences of carrier movement, deck wind and the airflow interference on aircraft considered. This model is applied to calculate and simulate the static balance of aircraft in different situations. The simulation and calculation results are consistent with the actual situation, which lays a foundation of dynamics analysis on carrier - based aircraft catapult launch with the six degrees of freedom model.

  16. Modeling and analyze of the environmental factors of carrier-based aircraft catapult launch in complex environment%复杂环境下舰载机弹射起飞环境因素建模分析

    Institute of Scientific and Technical Information of China (English)

    郭元江; 李会杰; 申功璋; 杨汀

    2011-01-01

    舰载机弹射起飞过程复杂,受到甲板运动、舰首气流、地面效应等复杂环境因素的影响.通过构建甲板运动模型、甲板风模型和地面效应模型,描述了弹射起飞过程中复杂的外部环境,并视为附加项加入到常规飞机方程中,建立了舰载机弹射起飞模型.研究表明:地面效应不利于舰载机弹射起飞;甲板风与舰首气流可抑制航迹下沉;舰面运动对舰载机离舰后下沉量影响很大.%The process of carrier-based aircraft catapult launch was complex,disturbed by the motion of aircraft carrier,deck wind,disturbance ahead of the bow and ground effect.The condition of carrier-based aircraft catapult launch was described by the simulation model of motion of aircraft carrier,deck wind,disturbance ahead of the bow and ground effect.The simulation model considering the condition of circumstance was composed of the model of plane and the model of circumstance condition,as the added factor.The results indicate that ground effect increases the flight path sinking,and the deck wind can help to decrease the flight path sinking during the catapult takeoff process.In addition,the motion of aircraft carrier has some important effects on maximum sinking and angle of attack.

  17. CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    WITTEKIND WD

    2007-10-03

    This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% {sup 239}Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: {sm_bullet}bare, {sm_bullet}1 inch of hydraulic fluid, or {sm_bullet}12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection.

  18. DCS Hydraulics Submittal, Butler County, Alabama, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  19. DCS Hydraulics Submittal, Bullock County, Alabama, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  20. DCS Hydraulics Submittal, Covington County, Alabama, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  1. 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)

  2. High Pressure Hydraulic Distribution System

    Science.gov (United States)

    1991-05-20

    to 500 0 F. 5 cycles. 5000 F room temperature to 50001F; 45 ______________ Icycles The tesis planned for the distribution system demonstrator were...American Society for Testing and Materials ASTM D412 - Tension Testing of Vulcanized Rubber ASTM D571 - Testing Automotive Hydraulic Brake Hose Society of

  3. Hydraulic fracturing system and method

    Energy Technology Data Exchange (ETDEWEB)

    Ciezobka, Jordan; Salehi, Iraj

    2017-02-28

    A hydraulic fracturing system and method for enhancing effective permeability of earth formations to increase hydrocarbon production, enhance operation efficiency by reducing fluid entry friction due to tortuosity and perforation, and to open perforations that are either unopened or not effective using traditional techniques, by varying a pump rate and/or a flow rate to a wellbore.

  4. Hydraulic jumps in a channel

    DEFF Research Database (Denmark)

    Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected...

  5. Hydraulic Fracture Containment in Sand

    NARCIS (Netherlands)

    Dong, Y.

    2010-01-01

    The mechanism of hydraulic fracturing in soft, high permeability material is considered fundamentally different from that in hard, low permeability rock, where a tensile fracture is created and conventional linear elastic fracture mechanics (LEFM) applies. The fracturing and associated modeling work

  6. Design of hydraulic recuperation unit

    Directory of Open Access Journals (Sweden)

    Jandourek Pavel

    2016-01-01

    Full Text Available This article deals with design and measurement of hydraulic recuperation unit. Recuperation unit consist of radial turbine and axial pump, which are coupled on the same shaft. Speed of shaft with impellers are 6000 1/min. For economic reasons, is design of recuperation unit performed using commercially manufactured propellers.

  7. Tree Hydraulics: How Sap Rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  8. Tree Hydraulics: How Sap Rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  9. A new linear type hydraulic motor

    Science.gov (United States)

    Jiang, Dong; Zhang, Tong; Li, Wenhua; Chen, Xinyang

    2017-08-01

    This paper proposes the design of liner type hydraulic motor on the base of inner curved radial piston hydraulic motor. The hydraulic cylinders of the new type motor are in the straight line which will improve the utilization of the axial space and different out power can be supplied by changes the number of cylinders. In this paper, the structure and working principle of the liner type hydraulic motor is introduced.

  10. Analysis of deck edge distance taking into account the catapult launch%考虑弹射起飞的航母剩余甲板长度研究

    Institute of Scientific and Technical Information of China (English)

    李新飞; 王立辉; 朱齐丹; 张智

    2015-01-01

    In order to study the range of deck edge distance after the catapult launch, the dynamics model of catapult launch is constructed considering the fast⁃extension of the nose gear. The dynamic process of the catapult launching on the deck is simulated and the most effective deck edge distance is designed considering the role of fast⁃extension of the nose gear. The take⁃off from the aircraft carrier is also analyzed and the minimum deck edge distance is chosen with respect to sink over the bow. The method of designing deck edge distance is proposed taking into account both the fast⁃extension of the nose gear and sink over the bow and it is validated in the catapult launch simulation. The re⁃search has practical significance and engineering value.%为了分析弹射行程结束之后剩余甲板长度的范围问题,建立了一种考虑舰载机前起落架突伸作用的弹射起飞动力学模型。对甲板弹射起飞阶段的动力学过程进行了仿真分析,从前起落架突伸作用的角度设计了最有效剩余甲板长度;对离舰起飞阶段进行了仿真分析,从舰载机下沉量的角度设计了最小剩余甲板长度。最后综合考虑前起落架突伸作用和下沉量,提出了一种剩余甲板长度设计方法,并得到了仿真结果的验证,具有重要的现实意义和工程价值。

  11. 舰载机弹射起飞上升段控制律研究%Control Law for Climbing Stage of Carrier-Based Aircraft in Catapult-Assisted Take-Off

    Institute of Scientific and Technical Information of China (English)

    朱熠; 江驹; 甄子洋; 王新华; 焦鑫

    2012-01-01

    针对舰载机的安全弹射起飞要求,研究了弹射起飞上升段控制律设计问题.分析了常用弹射装置原理以及弹射起飞的工作流程.构建了弹射起飞过程中的上升段相关数学模型,包括某型舰载机的纵向模型、前起落架突伸结构和阵风模型.设计了舰载机起飞离舰后上升段的飞行姿态控制律,在仿真中将加速滑跑阶段的各种因素转化成初始条件,同时分析了阵风干扰对上升段飞机飞行特性的影响.仿真结果表明:设计的姿态控制律可以改善舰载机在离舰上升段的姿态,抵抗气流干扰等因素的影响,提高弹射起飞的安全性.%According to the safety requirements of catapult-assisted take-off,the control law design for the aircraft in the climbing stage was studied. The principle of a common catapult device was studied and the process of catapult-assisted take-off was introduced. The mathematic models in the climbing stage were established, including the model of longitudinal small perturbation equations of the aircraft, the sudden stretch structure of the nose gear and the gust disturbance. The attitude control law of the climbing stage was designed. In simulation, the initial value was based on the influence of different factors in speeding stage. The influence of the gust disturbance on flight performance of the aircraft in its climbing stage was also analyzed. The results of simulation showed that the designed control law can improve the aircraft attitude in the climbing stage, decrease the adverse effect of gust disturbance, and thus can enhance the security of the catapult-assisted take-off.

  12. 应用电磁弹射器的舰载机起飞性能分析%Performance Analysis of Catapult Take-Off Process of Carrier-Based Aircraft Using Electromagnetic Aircraft Launch System

    Institute of Scientific and Technical Information of China (English)

    李静; 左斌; 路翠华

    2012-01-01

    针对应用电磁弹射器的舰载机弹射起飞过程,综合考虑了电磁弹射器的推力、舰载机前起落架突伸力和载舰的运动,建立了舰载机弹射起飞的数学模型,并据此,分析了上述各种因素对舰载机弹射起飞安全性的影响,计算得到在满足舰载机弹射起飞安全准则的条件下,各种起飞因素应该满足的适应范围。研究分析表明:在风浪较大的恶劣天气条件下,通过适当地增加电磁弹射器的电磁推力和前起落架的突伸力,可以有效抑制舰载机的航迹下沉现象,确保舰载机的安全起飞过程。%Taking into consideration the thrust force of electromagnetic launch system,the nose gear fast-extension force and the ship motion process,a mathematical model of a carrier-based aircraft using electromagnetic launch system during the catapult takeoff process was built.Based on the proposed model,the influence of the above factors on catapult take-off safety was analyzed.Moreover,the scales of several take-off factors which accord with the catapult take-off safety were computed.The results indicated that properly increasing the thrust force of electromagnetic launch system and enhancing the nose gear fast-extension force could help to decrease the flight path sinkage and guarantee the catapult take-off safety of the carrier-based aircraft under the condition of atrocious weather.

  13. 基于闭排队网络的弹射器数量配置方法%Method of the catapult quantity deployed by using closed queuing network

    Institute of Scientific and Technical Information of China (English)

    陈红召; 杨大鹏

    2016-01-01

    The catapult's quantity deployed is a major influencing factor on carrier aircrafts' sortie genera⁃tion rate. In the incipient designing period, the catapult quantity is also one of the important factors. Consid⁃ering the queuing characteristic of the launch process as well as the closed characteristic of the launch and recovery process, this paper proposes a closed queuing network based model for evaluating the influence of the catapult's quantity on sortie generation rate, which can be applied to the design of catapult's quantity. For validation, an example is designed based on the F/A-18's sortie and the recovery process in the Surge operation, whose calculating results agree well with the Surge operation.%弹射器配置数量对舰载机出动回收能力有很大影响,因此,在航母设计初期多方案论证阶段,弹射器的数量配置是必须考虑的关键问题之一。针对舰载机起飞过程的排队特点以及整个出动回收过程的闭环特点,基于排队理论建立舰载机出动回收过程的闭排队网络模型,分析弹射器数量对出动回收能力的影响,分析结果可用于支撑弹射器的数量配置设计方案。为验证模型的有效性,采用“高强度”演习中F/A-18舰载机的数据作为参数输入,结果显示模型计算分析结果与“高强度”演习结果一致。

  14. Hydraulic characterization of " Furcraea andina

    Science.gov (United States)

    Rivera-Velasquez, M. F.; Fallico, C.; Molinari, A.; Santillan, P.; Salazar, M.

    2012-04-01

    The present level of pollution, increasingly involving groundwaters, constitutes a serious risk for environment and human health. Therefore the remediation of saturated and unsaturated soils, removing pollutant materials through innovative and economic bio-remediation techniques is more frequently required. Recent studies on natural fiber development have shown the effectiveness of these fibers for removal of some heavy metals, due to the lignin content in the natural fibers which plays an important role in the adsorption of metal cations (Lee et al., 2004; Troisi et al., 2008; C. Fallico, 2010). In the context of remediation techniques for unsaturated and/or saturated zone, an experimental approach for the hydraulic characterization of the "Furcraea andina" (i.e., Cabuya Blanca) fiber was carried out. This fiber is native to Andean regions and grows easily in wild or cultivated form in the valleys and hillsides of Colombia, Ecuador, and Peru. Fibers of "Furcraea andina" were characterized by experimental tests to determine their hydraulic conductivity or permeability and porosity in order to use this medium for bioremediation of contaminated aquifer exploiting the physical, chemical and microbial capacity of natural fiber in heavy metal adsorption. To evaluate empirically the hydraulic conductivity, laboratory tests were carried out at constant head specifically on the fibers manually extracted. For these tests we used a flow cell (used as permeameter), containing the "Furcraea andina" fibers to be characterized, suitably connected by a tygon pipe to a Marriott's bottle, which had a plastic tube that allow the adjustment of the hydraulic head for different tests to a constant value. By this experiment it was also possible to identify relationships that enable the estimation of permeability as a function of density, i.e. of the compaction degree of the fibers. Our study was carried out for three values of hydraulic head (H), namely 10, 18, and 25 cm and for each

  15. Measurements of Jets in ALICE

    CERN Document Server

    Nattrass, Christine

    2016-01-01

    The ALICE detector can be used for measurements of jets in pp , p Pb, and Pb–Pb collisions. Measurements of jets in pp collisions are consis- tent with expectations from perturbative calculations and jets in p Pb scale with the number of nucleon–nucleon collisions, indicating that cold nuclear matter effects are not observed for jets. Measurements in Pb–Pb collisions demonstrate suppression of jets relative to expectations from binary scaling to the equivalent number of nucleon–nucleon collisions

  16. 14 CFR 25.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 25.1435 Section 25.1435... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed to: (1) Withstand the proof...

  17. 14 CFR 27.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 27.1435 Section 27.1435... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand, without yielding, any structural loads...

  18. Astrophysics: Cosmic jet engines

    Science.gov (United States)

    Young, Andy

    2010-02-01

    In some galaxies, matter falling onto a supermassive black hole is ejected in narrow jets moving at close to the speed of light. New observations provide insight into the workings of these cosmic accelerators.

  19. Jet lag prevention

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000719.htm Jet lag prevention To use the sharing features on this page, ... Headache Irritability Stomach upset Sore muscles Tips for Prevention Before your trip: Get plenty of rest, eat ...

  20. Jet Engine Noise Reduction

    Science.gov (United States)

    2009-04-01

    Technology Solutions, Lockheed Martin Robert S. Carnes , M.D. NRAC Member, Battelle Memorial Institute MajGen Paul A. Fratarangelo, USMC (Ret) NRAC...Development, Acquisition) (VADM Architzel). The Naval Research Advisory Committee members (Bowes, Bowler, Carnes and Fratarangelo) have broad...Lockheed Martin ADP Boeing: Jet Engine Noise Reduction for Tactical Fighter Aircraft Mr. Tom Kaemming, K. Viswanathan, Ph . D. Tactical Jet Noise

  1. CFD study of turbulent jet impingement on curved surface

    Institute of Scientific and Technical Information of China (English)

    Javad Taghinia; Md Mizanur Rahman; Timo Siikonen

    2016-01-01

    The heat transfer and flow characteristics of air jet impingement on a curved surface are investigated with com-putational fluid dynamics (CFD) approach. The first applied model is a one-equation SGS model for large eddy simulation (LES) and the second one is the SST-SAS hybrid RANS-LES. These models are utilized to study the flow physics in impinging process on a curved surface for different jet-to-surface (h/B) distances at two Reynolds numbers namely, 2960 and 4740 based on the jet exit velocity (Ue) and the hydraulic diameter (2B). The predic-tions are compared with the experimental data in the literature and also the results from RANS k-εmodel. Com-parisons show that both models can produce relatively good results. However, one-equation model (OEM) produced more accurate results especial y at impingement region at lower jet-to-surface distances. In terms of heat transfer, the OEM also predicted better at different jet-to-surface spacings. It is also observed that both models show similar performance at higher h/B ratios.

  2. Jets and QCD

    CERN Document Server

    Ali, Ahmed

    2010-01-01

    The observation of quark and gluon jets has played a crucial role in establishing Quantum Chromodynamics [QCD] as the theory of the strong interactions within the Standard Model of particle physics. The jets, narrowly collimated bundles of hadrons, reflect configurations of quarks and gluons at short distances. Thus, by analysing energy and angular distributions of the jets experimentally, the properties of the basic constituents of matter and the strong forces acting between them can be explored. In this review we summarise the properties of quark and gluon jets and the impact of their observation on Quantum Chromodynamics, primarily the discovery of the gluons as the carriers of the strong force. Focusing on these basic points, jets in $e^+ e^-$ collisions will be in the foreground of the discussion. In addition we will delineate the role of jets as tools for exploring other particle aspects in $ep$ and $pp/p\\bar{p}$ collisions - quark and gluon densities in protons, measurements of the QCD coupling, fundam...

  3. Jet engine. Strahltriebwerk

    Energy Technology Data Exchange (ETDEWEB)

    Weber, F.J.

    1990-11-15

    A gas turbine axial-flow compressor aggregate is mounted in a jet engine consisting of a high-temperature combustion chamber that is composed of conical rings forming slits and set together to a ring column and reaches up to the propelling nozzle, a compressed-air generator supplying the jet engine with compressed air at subsonic speeds and running into the propelling nozzle and a shell encasing the jet engine while leaving a certain intermediate space. The compressor aggregate has a relatively high fuel consumption and high emission rates, involves high production and maintenance costs and puts the blades at a high risk of overheating. The problem basic to the invention was to install a compressed-air generator in the jet engine that has lower fuel consumption and emission rates and is cheaper to manufacture and to service. The invention provides free-piston compressors for compressed-air generators arranged in a circle around the central high-temperature combustion chamber. The ring of compressors can rotate on bearings against the jet engine shell, so that each compressor can be turned to the bottom and serviced there. The jet engine is suitable as an engine for supersonic aircraft.

  4. Jet Mass Spectra in Higgs + One Jet at NNLL

    CERN Document Server

    Jouttenus, Teppo T; Tackmann, Frank J; Waalewijn, Wouter J

    2013-01-01

    The invariant mass of a jet is a benchmark variable describing the structure of jets at the LHC. We calculate the jet mass spectrum for Higgs plus one jet at the LHC at next-to-next-to-leading logarithmic (NNLL) order using a factorization formula. At this order, the cross section becomes sensitive to perturbation theory at the soft m_jet^2/p_T^jet scale. Our calculation is exclusive and uses the 1-jettiness global event shape to implement a veto on additional jets. The dominant dependence on the jet veto is removed by normalizing the spectrum, leaving residual dependence from non-global logarithms depending on the ratio of the jet mass and jet veto variables. For our exclusive jet cross section these non-global logarithms are parametrically smaller than in the inclusive case, allowing us to obtain a complete NNLL result. Results for the dependence of the jet mass spectrum on the kinematics, jet algorithm, and jet size R are given. Using individual partonic channels we illustrate the difference between the je...

  5. Thermal Hydraulic Performance of Tight Lattice Bundle

    Science.gov (United States)

    Yamamoto, Yasushi; Akiba, Miyuki; Morooka, Shinichi; Shirakawa, Kenetsu; Abe, Nobuaki

    Recently, the reduced moderation spectrum BWR has been studied. The fast neutron spectrum is obtained through triangular tight lattice fuel. However, there are few thermal hydraulic test data and thermal hydraulic correlation applicable to critical power prediction in such a tight lattice bundle. This study aims to enhance the database of the thermal hydraulic performance of the tight lattice bundle whose rod gap is about 1mm. Therefore, thermal hydraulic performance measurement tests of tight lattice bundles for the critical power, the pressure drop and the counter current flow limiting were performed. Moreover, the correlations to evaluate the thermal-hydraulic performance of the tight lattice bundle were developed.

  6. Design of hydraulic output Stirling engine

    Science.gov (United States)

    Toscano, W. M.; Harvey, A. C.; Lee, K.

    1983-01-01

    A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency.

  7. Research on Disc Spring Buffering the Backward Impact of Piston of Liquid-Jet Hydraulic Hammer Based on LS-DYNA%基于 LS -DYNA 的射流式液动锤活塞回程缓冲结构的研究

    Institute of Scientific and Technical Information of China (English)

    杨冬冬; 李国琳; 纪天坤; 孙强; 彭枧明

    2016-01-01

    为了减弱射流式液动锤活塞回程撞击缸体的应力波对射流元件的破坏,延长射流元件的寿命,提出在缸体中设置碟簧缓冲结构来吸收冲锤回程的冲击能,并应用LS-DYNA显示动力学分析手段,对活塞回程进行仿真分析,探究碟簧缓冲对射流元件受力状态的影响,结果表明:采用碟簧缓冲结构,射流元件的最大应力可降低40%~57%,有效改善了射流元件的应力状态,在液动锤实际工作中具有可行性。%In order to reduce the damage to fluidic element caused by stress waves from impacting cylinder in a return-stroke of the fluidic hydraulic hammer piston to prolong the life of the fluidic element, a disc spring buffer structure in the cylinder was proposed to absorb the striking energy of hammer stroke.The simulation analysis was carried out on the piston return-stroke by the means of LS-DYNA display dynamic analysis to study the effect of the disc spring buffer on the stress state of bi-stable fluidic amplifier.The results show the feasiblility of disc spring buffer structure in the actual work of hy-draulic hammer, the maximum stress can be decreased by 40%~57%in bi-stable fluidic amplifier and the stress state of fluidic element is effectively improved.

  8. Hydraulic fracture during epithelial stretching

    Science.gov (United States)

    Casares, Laura; Vincent, Romaric; Zalvidea, Dobryna; Campillo, Noelia; Navajas, Daniel; Arroyo, Marino; Trepat, Xavier

    2015-03-01

    The origin of fracture in epithelial cell sheets subject to stretch is commonly attributed to excess tension in the cells’ cytoskeleton, in the plasma membrane, or in cell-cell contacts. Here, we demonstrate that for a variety of synthetic and physiological hydrogel substrates the formation of epithelial cracks is caused by tissue stretching independently of epithelial tension. We show that the origin of the cracks is hydraulic; they result from a transient pressure build-up in the substrate during stretch and compression manoeuvres. After pressure equilibration, cracks heal readily through actomyosin-dependent mechanisms. The observed phenomenology is captured by the theory of poroelasticity, which predicts the size and healing dynamics of epithelial cracks as a function of the stiffness, geometry and composition of the hydrogel substrate. Our findings demonstrate that epithelial integrity is determined in a tension-independent manner by the coupling between tissue stretching and matrix hydraulics.

  9. Study on Effect of Damping Hole in Pneumatic Catapult on Performance of System%气动弹射器阻尼孔对系统性能影响的研究

    Institute of Scientific and Technical Information of China (English)

    刘救世; 马胜钢; 董攀辉; 窦小鹏; 裴东杰

    2014-01-01

    以新型贮气瓶供气气动弹射器为研究对象,建立了系统的数学模型,借助MATLAB仿真软件编制了系统的仿真模型,通过仿真研究获得了该弹射器阻尼孔对弹射过程中关键工作参数及系统性能的影响的规律,为详细设计该系统提供了依据。%By taking a new type of pneumatic catapult powered by gas tanks as the research object,the mathematical model of the system was established,and the simulation model of ejection system was programmed using MATLAB simulation software.The rules of influences on main working parameters and performance of system by the damping hole of the catapult have been obtained in the ejec-tion process through the simulation research.Thus it lays a theoretical foundation for the detailed design of the system.

  10. The hydraulic jump and ripples in liquid helium

    Energy Technology Data Exchange (ETDEWEB)

    Rolley, E. [Laboratoire de Physique Statistique de l' ENS, associe au CNRS et aux Universites Paris 6 et Paris 7, 24 rue Lhomond, 75005 Paris (France)]. E-mail: rolley@lps.ens.fr; Guthmann, C. [Laboratoire de Physique Statistique de l' ENS, associe au CNRS et aux Universites Paris 6 et Paris 7, 24 rue Lhomond, 75005 Paris (France); Pettersen, M.S. [Washington and Jefferson College, 60 S. Lincoln St., Washington, PA 15301 (United States)

    2007-05-01

    We have studied the characteristics of the circular hydraulic jump using liquid helium. Surprisingly, the radius of the jump does not change at the superfluid transition. We think that the flow is still dissipative below the lambda point because the velocity exceeds the critical one. The jump radius R{sub j} is compared with various models. In our parameter range, we find that the jump can be treated as a shock, and that capillary effects are important. Below the superfluid transition, we observed a standing capillary wave between the impact of the jet and the jump. Assuming that the superfluid flow can be described with an effective viscosity, we calculate the wave vector and thus obtain the value of the liquid thickness, which is in reasonable agreement with predictions. However, the spatial variation of the wave amplitude depends much more strongly on temperature than we calculate.

  11. Bio-based Hydraulic Fluids

    Science.gov (United States)

    2008-04-17

    currently formulated with vegetable oils (i.e., rapeseed , sun flower, corn, soybean, canola, coconut, etc.) and synthetic ester, such as polyol ester...2008 Vegetable Oil • Excellent lubrication • Nontoxic • Biodegradable • Derived from renewable resources such as rapeseed , sunflower, corn...Mineral Oil 100 SAE 15W-40 G Rapeseed 32 Commercial HF H Polyol ester 22 MIL-PRF-32073 Grade 2 I Canola - Cooking Oil *Hydraulic fluid 3717 April

  12. Fire Resistant Aircraft Hydraulic System.

    Science.gov (United States)

    1982-07-01

    and compounds based on new experimental elastomers as well as most commercially available elastomers were screened in seeking seals that were both...for hydraulic component testing. All of the available E6.5 stock was purchased for the screening tests. However, DuPont stated that other homologs of...with the lubricity and anti-wear additive olyvan A (molybdenum oxysulphide dithiocarbamate ) added in the quantity of less than one percent by weight

  13. Carrier-based aircraft steam catapult system with feedback linearization control%舰载机蒸汽弹射反馈线性控制系统研究

    Institute of Scientific and Technical Information of China (English)

    刘恒; 朱齐丹; 李晓琳; 董然

    2016-01-01

    To study the states'change of accumulator and cylinder in steam catapult aircraft launch, aiming at the nonlinear coupling characteristics of the cylinder system, considering the flashing phenomenon in the steam accu⁃mulator, the pressure change of chamber with rod and without rod in the steam cylinder, and the relationship be⁃tween launching valve's core displacement and flow area, the steam accumulator and launching valve mathematical model, cylinder thermodynamic model and the aircraft six degrees of freedom dynamics model were established, and the launching valve controller of steam catapult system was accomplished. The simulation finds that the pres⁃sure⁃drop steam catapult system was extremely small, almost negligible in the catapult period; moreover, because of the nonlinear and coupling characteristics of the cylinder system, the traditional control method cannot accom⁃plish a stable launching valve, whose opening degree experiences strong mutations when opened and closed. Based on the feedback linearization theory, the steam cylinder model can be completely linearized and can decouple cylin⁃der state variables, contributing to the design of the launching valve controller. The simulation shows that using the feedback linearization method, the launching valve regulator can perform in a stable manner, achieving acceptable acceleration tracking effect during the catapult process.%为了研究舰载机蒸汽弹射过程中储汽筒与汽缸中各状态的变化,针对汽缸系统的非线性强耦合特点,考虑储汽筒内闪蒸现象、汽缸有杆腔与无杆腔压力变化以及发射阀芯位移与流通面积之间的关系,建立储汽筒、发射阀的数学模型,汽缸的热力学模型以及舰载机的六自由度运动模型,完成蒸汽弹射系统发射阀控制器设计。通过仿真研究发现,蒸汽弹射系统的储汽筒在弹射阶段压降很小,其影响可以忽略;并且,由于汽缸系统的各状态

  14. 基于排队论的大型舰船甲板弹射器数量研究%Investigation into Deck Catapults Quantity of Large Ship by Using Queuing Theory

    Institute of Scientific and Technical Information of China (English)

    周鑫磊; 孟祥印; 解学参; 胡玉龙; 侯远杭

    2011-01-01

    The objective of this article is to establish a theoretical basis for determining the quantity of catapult on the flight deck of large ship. As for investigation, the approach of "dummy queue (virtual queue)" was presented from the view of aircraft handling officer, and the task flow model was set up and analysis was carried out by using the queuing theory. The realistic model of task flow of carrier-based aircraft in standby position for launch was also constructed. A multiple calculations were conducted for the key targets, ignoring all the other factors, with regard to the influence of different quantities of catapults on the virtual length of aircraft's waiting queue and time of the system standby based on the assumption of the queuing theory. The results enable to have a quantifying comparison of sortie generation capacities of carried-based aircraft on the flight deck. The calculations also showed that under a given set of conditions, increasing the quantity of the catapult can obviously minimize the queuing length of the birds waiting in a queue for launch on the flight deck, but, if the number of catapult was greater than four, this would be less effective. Through the calculating results, application of the queuing theory to the demonstration as well as quantity design of catapult on large ship is proved to be practicable.%为明确大型舰船飞行甲板弹射器数量设计的理论依据,从调运指挥官的角度提出了"虚拟队列"概念,分析了其工作特点,对其工作模式进行了排队论建模.同时分析、建立了舰载机在弹射等待过程中的真实排队模型.忽略其它甲板因素的影响,基于排队论假设代入数值计算了不同弹射器数量对虚拟队列中舰载机的等待队长、系统等待耗时等关键指标的影响,使弹射器数量影响下的大型舰船舰载机出动能力得到了量化比较.计算结果表明,在给定条件下,甲板弹射器数量的增加能有效减少大型舰船舰

  15. [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.

  16. B-jets and z + b-jets at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Jeans, Daniel; /Rome U.

    2006-06-01

    The authors present CDF cross-section measurements for the inclusive production of b jets and the production of b jets in association with a Z{sup 0} boson. Both measurements are in reasonable agreement with NLO QCD predictions.

  17. Hydraulic Redistribution: A Modeling Perspective

    Science.gov (United States)

    Daly, E.; Verma, P.; Loheide, S. P., III

    2014-12-01

    Roots play a key role in the soil water balance. They extract and transport water for transpiration, which usually represents the most important soil water loss in vegetated areas, and can redistribute soil water, thereby increasing transpiration rates and enhancing root nutrient uptake. We present here a two-dimensional model capable of describing two key aspects of root water uptake: root water compensation and hydraulic redistribution. Root water compensation is the ability of root systems to respond to the reduction of water uptake from areas of the soil with low soil water potential by increasing the water uptake from the roots in soil parts with higher water potential. Hydraulic redistribution is a passive transfer of water through the root system from areas of the soil with greater water potential to areas with lower water potential. Both mechanisms are driven by gradients of water potential in the soil and the roots. The inclusion of root water compensation and hydraulic redistribution in models can be achieved by describing root water uptake as a function of the difference in water potential between soil and root xylem. We use a model comprising the Richards equation for the water flow in variably saturated soils and the Darcy's equation for the water flow in the xylem. The two equations are coupled via a sink term, which is assumed to be proportional to the difference between soil and xylem water potentials. The model is applied in two case studies to describe vertical and horizontal hydraulic redistribution and the interaction between vegetation with different root depths. In the case of horizontal redistribution, the model is used to reproduce the fluxes of water across the root system of a tree subjected to uneven irrigation. This example can be extended to situations when only part of the root system has access to water, such as vegetation near creeks, trees at the edge of forests, and street trees in urban areas. The second case is inspired by recent

  18. 齿轮增速式液压弹射器弹射过程的仿真分析%Simulation Analysis on Hydraulic Catapult Ejection Process of Gear Increaser

    Institute of Scientific and Technical Information of China (English)

    刘兰荣; 马笑尘

    2016-01-01

    以齿轮增速式液压弹射器的弹射过程为研究对象,运用功率键合图法建立了弹射过程的数学模型,利用MATLAB软件建立仿真模型并进行了详细的仿真分析,得到了弹射过程中关键参数对弹射性能的影响,为中重型无人机弹射起飞的研究提供了理论依据.

  19. 无人机液压弹射器弹射过程的仿真分析与试验研究%Simulation Analysis and Experimental Research of UAV Hydraulic Catapult Ejection Process

    Institute of Scientific and Technical Information of China (English)

    刘兰荣; 马笑尘

    2016-01-01

    以液压蓄能器为动力源、液压马达为执行元件的无人机液压弹射器的弹射过程为研究对象,运用功率键合图法建立了弹射过程的数学模型,利用仿真分析结合实验对该过程进行了详细的研究,得到了弹射过程中关键工作参数对弹射性能的影响,为弹射系统的研发与改进提供了重要依据.

  20. Relativistic AGN jets I. The delicate interplay between jet structure, cocoon morphology and jet-head propagation

    NARCIS (Netherlands)

    Walg, S.; Achterberg, A.; Markoff, S.; Keppens, R.; Meliani, Z.

    2013-01-01

    Astrophysical jets reveal strong signs of radial structure. They suggest that the inner region of the jet, the jet spine, consists of a low-density, fast-moving gas, while the outer region of the jet consists of a more dense and slower moving gas, called the jet sheath. Moreover, if jets carry angul

  1. Jet Substructure by Accident

    CERN Document Server

    Cohen, Timothy; Lisanti, Mariangela; Lou, Hou Keong

    2012-01-01

    We propose a new search strategy for high-multiplicity hadronic final states. When new particles are produced at threshold, the distribution of their decay products is approximately isotropic. If there are many partons in the final state, it is likely that several will be clustered into the same large-radius jet. The resulting jet exhibits substructure, even though the parent states are not boosted. This "accidental" substructure is a powerful discriminant against background because it is more pronounced for high-multiplicity signals than for QCD multijets. We demonstrate how to take advantage of accidental substructure to reduce backgrounds without relying on the presence of missing energy. As an example, we present the expected limits for several R-parity violating gluino decay topologies. This approach allows for the determination of QCD backgrounds using data-driven methods, which is crucial for the feasibility of any search that targets signatures with many jets and suppressed missing energy.

  2. Renewable jet fuel.

    Science.gov (United States)

    Kallio, Pauli; Pásztor, András; Akhtar, M Kalim; Jones, Patrik R

    2014-04-01

    Novel strategies for sustainable replacement of finite fossil fuels are intensely pursued in fundamental research, applied science and industry. In the case of jet fuels used in gas-turbine engine aircrafts, the production and use of synthetic bio-derived kerosenes are advancing rapidly. Microbial biotechnology could potentially also be used to complement the renewable production of jet fuel, as demonstrated by the production of bioethanol and biodiesel for piston engine vehicles. Engineered microbial biosynthesis of medium chain length alkanes, which constitute the major fraction of petroleum-based jet fuels, was recently demonstrated. Although efficiencies currently are far from that needed for commercial application, this discovery has spurred research towards future production platforms using both fermentative and direct photobiological routes. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Multichannel discharge between jet electrolyte cathode and jet electrolyte anode

    NARCIS (Netherlands)

    Shakirova, E. F.; Gaitsin, Al. F.; Son, E. E.

    2011-01-01

    We present the results of an experimental study of multichannel discharge between a jet electrolyte cathode and jet electrolyte anode within a wide range of parameters. We pioneer the reveal of the burning particularities and characteristics of multichannel discharge with jet electrolyte and droplet

  4. A Study on the Pressure Relief Scope and the Stress Variation of Hydraulic Flushing Borehole

    Directory of Open Access Journals (Sweden)

    C. F.Wei

    2014-01-01

    Full Text Available To study the variation of the pressure relief scope and the stress around hydraulic flushing borehole, the theory of coalrock damage was utilized to distinguish the interaction area of water-jet and coal-rock into the coal-rock crushing area, the water-jet pressure stagnation area, the transition area and the original stress recovery area of coal-rock. Based on the actual occurrence conditions of the coal seam, the pressure variation and relief scope around the hydraulic flushing borehole were analyzed and simulated by RFPA2D-Flow software. The results showed that a relief area with the radius of 5.0 ~ 6.0 m around the borehole formed due to the hydraulic flushing with the pressure relief of 0.038 ~ 6.545 MPa, and the maximum principal stress is 15.85 MPa with a distance of 6.8 m from the inspected hole where stress concentration appeared. After hydraulic flushing test, the diameter (441.8 ~ 1171.6 mm of the hole which can be an expression of coal crushing area size, was calculated based on the examination of the coal amount through the trial process, and it can be drawn that the pressure relief area must be larger than that of the coal-rock crushing area. Meanwhile, the measured pressures relief range(5.96 ~ 6.62 m is basically consistent with the numerical simulation result (5.0 ~ 6.0 m which verified the accuracy of the simulation analysis, according to the distance from the inspection drilling to the hydraulic flushing borehole and the decreased degree of the gas content in the inspection hole by the way of Gas Content.

  5. Relativistic AGN jets I. The delicate interplay between jet structure, cocoon morphology and jet-head propagation

    Science.gov (United States)

    Walg, S.; Achterberg, A.; Markoff, S.; Keppens, R.; Meliani, Z.

    2013-08-01

    Astrophysical jets reveal strong signs of radial structure. They suggest that the inner region of the jet, the jet spine, consists of a low-density, fast-moving gas, while the outer region of the jet consists of a more dense and slower moving gas, called the jet sheath. Moreover, if jets carry angular momentum, the resultant centrifugal forces lead to a radial stratification. Current observations are not able to fully resolve the radial structure, so little is known about its actual profile. We present three active galactic nuclei jet models in 2.5D of which two have been given a radial structure. The first model is a homogeneous jet, the only model that does not carry angular momentum; the second model is a spine-sheath jet with an isothermal equation of state; and the third jet model is a (piecewise) isochoric spine-sheath jet, with constant but different densities for jet spine and jet sheath. In this paper, we look at the effects of radial stratification on jet integrity, mixing between the different jet components and global morphology of the jet-head and surrounding cocoon. We consider steady jets that have been active for 23 Myr. All jets have developed the same number of strong internal shocks along their jet axis at the final time of simulation. These shocks arise when vortices are being shed by the jet-head. We find that all three jets maintain their stability all the way up to the jet-head. The isothermal jet maintains part of its structural integrity at the jet-head where the distinction between jet spine and jet sheath material can still be made. In this case, mixing between jet spine and jet sheath within the jet is fairly inefficient. The isochoric jet, on the other hand, loses its structural jet integrity fairly quickly after the jet is injected. At its jet-head, little structure is maintained and the central part of the jet predominantly consists of jet sheath material. In this case, jet spine and jet sheath material mix efficiently within the jet

  6. Resolving boosted jets with XCone

    Energy Technology Data Exchange (ETDEWEB)

    Thaler, Jesse; Wilkason, Thomas F. [Center for Theoretical Physics, Massachusetts Institute of Technology,Cambridge, MA, 02139 (United States)

    2015-12-09

    We show how the recently proposed XCone jet algorithm http://dx.doi.org/10.1007/JHEP11(2015)072 smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies — dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs — that demonstrate the physics applications of XCone over a wide kinematic range.

  7. Resolving boosted jets with XCone

    Science.gov (United States)

    Thaler, Jesse; Wilkason, Thomas F.

    2015-12-01

    We show how the recently proposed XCone jet algorithm [1] smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies — dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs — that demonstrate the physics applications of XCone over a wide kinematic range.

  8. Resolving Boosted Jets with XCone

    CERN Document Server

    Thaler, Jesse

    2015-01-01

    We show how the recently proposed XCone jet algorithm smoothly interpolates between resolved and boosted kinematics. When using standard jet algorithms to reconstruct the decays of hadronic resonances like top quarks and Higgs bosons, one typically needs separate analysis strategies to handle the resolved regime of well-separated jets and the boosted regime of fat jets with substructure. XCone, by contrast, is an exclusive cone jet algorithm that always returns a fixed number of jets, so jet regions remain resolved even when (sub)jets are overlapping in the boosted regime. In this paper, we perform three LHC case studies---dijet resonances, Higgs decays to bottom quarks, and all-hadronic top pairs---that demonstrate the physics applications of XCone over a wide kinematic range.

  9. Jet Photoproduction at THERA

    OpenAIRE

    Klasen, M.

    2001-01-01

    We demonstrate that a future high-energy electron-proton collider like THERA could largely extend the current HERA program in jet photoproduction of testing QCD and determining the partonic structure of the proton and the photon. Depending on the electron beam energy (250-500 GeV) and the collider mode ($ep$ or $\\gamma p$), the range in the hard transverse energy scale of the jets could be increased by a factor of 2-3 and the reach in the momentum fraction $x$ of the partons in the proton or ...

  10. Jet Physics in ATLAS

    CERN Document Server

    Sandoval, C; The ATLAS collaboration

    2012-01-01

    Measurements of hadronic jets provide tests of strong interactions which are interesting both in their own right and as backgrounds to many New Physics searches. It is also through tests of Quantum Chromodynamics that new physics may be discovered. The extensive dataset recorded with the ATLAS detector throughout the 7 TeV centre-of-mass LHC operation period allows QCD to be probed at distances never reached before. We present a review of selected ATLAS jet physics measurements. These measurements constitute precision tests of QCD in a new energy regime, and show sensitivity to the parton densities in the proton and to the value of the strong coupling, alpha_s.

  11. OPAL Jet Chamber Prototype

    CERN Multimedia

    OPAL was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. OPAL's central tracking system consists of (in order of increasing radius) a silicon microvertex detector, a vertex detector, a jet chamber, and z-chambers. All the tracking detectors work by observing the ionization of atoms by charged particles passing by: when the atoms are ionized, electrons are knocked out of their atomic orbitals, and are then able to move freely in the detector. These ionization electrons are detected in the dirfferent parts of the tracking system. This piece is a prototype of the jet chambers

  12. Sanitary Sewage Treatment with Jet Inner-loop Bioreactor

    Institute of Scientific and Technical Information of China (English)

    Wen Qin-xue; Chen Zhi-qiang; Lu Bing-nan; Wen Yan

    2004-01-01

    A jet inncr-loop bioreactor (JIBR) was used to treat synthetic sanitary sewage with low, medium and high COD load. The experimental resuhs show that it could meet discharge standard at 20-30 min of HRT (hydraulic retention time) for low COD concentration and 60-120 min of HRT for medium and high COD concentration. The maximal COD volume loading and COD sludye loading of 27kg·m-3·d-1 and 5 kg/d per kg MLSS were achieved respectively, that were 10-20 times higher than those of traditional wastewater treatment processes. The BOD5 removal efficiency was more than 90 % and NH1-N more than 85 %. The study on the activity showed that the oxygen consumption rate of the activated times higher than that of the SBR(Sequencing Batch Reactor)and thc dominant bacteria in jet inner-loop bioreactor was Pseudomonas species.

  13. Vibrations of hydraulic pump and their solution

    OpenAIRE

    Dobšáková Lenka; Nováková Naděžda; Habán Vladimír; Hudec Martin; Jandourek Pavel

    2017-01-01

    The vibrations of hydraulic pump and connected pipeline system are very problematic and often hardly soluble. The high pressure pulsations of hydraulic pump with the double suction inlet are investigated. For that reason the static pressure and accelerations are measured. The numerical simulations are carried out in order to correlate computed data with experimental ones and assess the main source of vibrations. Consequently the design optimization of the inner hydraulic part of pump is done ...

  14. 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

  15. Jet substructure using semi-inclusive jet functions within SCET

    CERN Document Server

    Kang, Zhong-Bo; Vitev, Ivan

    2016-01-01

    We propose a new method to evaluate jet substructure observables in inclusive jet measurements based upon semi-inclusive jet functions within the framework of Soft Collinear Effective Theory (SCET). In this work we consider the jet fragmentation function, where a hadron $h$ is identified inside a fully reconstructed jet as a first example. We introduce a new semi-inclusive fragmenting jet function ${\\mathcal G}^h_i(z= \\omega_J/\\omega,z_h=\\omega_h/\\omega_J,\\omega_J, R,\\mu)$ which depends on the jet radius $R$ and the large light-cone momenta of the parton '$i$' initiating the jet ($\\omega$), the jet ($\\omega_J$), and the hadron $h$ ($\\omega_h$). We are then able to express the jet fragmentation function as a semi-inclusive jet observable rather than as an exclusive one, which is closer to the actual experimental measurements. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations at next-to-leading order (NLO). We further derive the renormalization gro...

  16. Intermonsoonal equatorial jets

    Digital Repository Service at National Institute of Oceanography (India)

    Muraleedharan, P.M.

    Three transects each from the cruises of R V Pioneer (84 , 88 degrees and 92 degrees E) during May-June 1964 and R V Vityaz (77 , 84 degrees and 94 degrees E) during October-November 1962 were used to compare pre and postmonsoon equatorial jets...

  17. Fluid Jet Polishing

    NARCIS (Netherlands)

    Booij, S.M.

    2003-01-01

    The goal of this thesis research was to investigate the possibilities and limitations of the Fluid Jet Polishing (FJP) technique. FJP is a new optical fabrication technique that is capable of making shape corrections and reducing the surface roughness of glass and other materials. The principle of o

  18. Fluid Jet Polishing

    NARCIS (Netherlands)

    Booij, S.M.

    2003-01-01

    The goal of this thesis research was to investigate the possibilities and limitations of the Fluid Jet Polishing (FJP) technique. FJP is a new optical fabrication technique that is capable of making shape corrections and reducing the surface roughness of glass and other materials. The principle of

  19. Jet-Images: Computer Vision Inspired Techniques for Jet Tagging

    CERN Document Server

    Cogan, Josh; Strauss, Emanuel; Schwarztman, Ariel

    2014-01-01

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon- initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  20. Jet-images: computer vision inspired techniques for jet tagging

    Energy Technology Data Exchange (ETDEWEB)

    Cogan, Josh; Kagan, Michael; Strauss, Emanuel; Schwarztman, Ariel [SLAC National Accelerator Laboratory,Menlo Park, CA 94028 (United States)

    2015-02-18

    We introduce a novel approach to jet tagging and classification through the use of techniques inspired by computer vision. Drawing parallels to the problem of facial recognition in images, we define a jet-image using calorimeter towers as the elements of the image and establish jet-image preprocessing methods. For the jet-image processing step, we develop a discriminant for classifying the jet-images derived using Fisher discriminant analysis. The effectiveness of the technique is shown within the context of identifying boosted hadronic W boson decays with respect to a background of quark- and gluon-initiated jets. Using Monte Carlo simulation, we demonstrate that the performance of this technique introduces additional discriminating power over other substructure approaches, and gives significant insight into the internal structure of jets.

  1. Hydraulically Driven Grips For Hot Tensile Specimens

    Science.gov (United States)

    Bird, R. Keith; Johnson, George W.

    1994-01-01

    Pair of grips for tensile and compressive test specimens operate at temperatures up to 1,500 degrees F. Grips include wedges holding specimen inside furnace, where heated to uniform temperature. Hydraulic pistons drive wedges, causing them to exert clamping force. Hydraulic pistons and hydraulic fluid remain outside furnace, at room temperature. Cooling water flows through parts of grips to reduce heat transferred to external components. Advantages over older devices for gripping specimens in high-temperature tests; no need to drill holes in specimens, maintains constant gripping force on specimens, and heated to same temperature as that of specimen without risk of heating hydraulic fluid and acuator components.

  2. Jet substructure using semi-inclusive jet functions in SCET

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Zhong-Bo [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States); Department of Physics and Astronomy, University of California,Los Angeles, CA 90095 (United States); Ringer, Felix; Vitev, Ivan [Theoretical Division, Los Alamos National Laboratory,Los Alamos, NM 87545 (United States)

    2016-11-25

    We propose a new method to evaluate jet substructure observables in inclusive jet measurements, based upon semi-inclusive jet functions in the framework of Soft Collinear Effective Theory (SCET). As a first example, we consider the jet fragmentation function, where a hadron h is identified inside a fully reconstructed jet. We introduce a new semi-inclusive fragmenting jet function G{sub i}{sup h}(z=ω{sub J}/ω,z{sub h}=ω{sub h}/ω{sub J},ω{sub J},R,μ), which depends on the jet radius R and the large light-cone momenta of the parton ‘i’ initiating the jet (ω), the jet (ω{sub J}), and the hadron h (ω{sub h}). The jet fragmentation function can then be expressed as a semi-inclusive observable, in the spirit of actual experimental measurements, rather than as an exclusive one. We demonstrate the consistency of the effective field theory treatment and standard perturbative QCD calculations of this observable at next-to-leading order (NLO). The renormalization group (RG) equation for the semi-inclusive fragmenting jet function G{sub i}{sup h}(z,z{sub h},ω{sub J},R,μ) are also derived and shown to follow exactly the usual timelike DGLAP evolution equations for fragmentation functions. The newly obtained RG equations can be used to perform the resummation of single logarithms of the jet radius parameter R up to next-to-leading logarithmic (NLL{sub R}) accuracy. In combination with the fixed NLO calculation, we obtain NLO+NLL{sub R} results for the hadron distribution inside the jet. We present numerical results for pp→(jet h)X in the new framework, and find excellent agreement with existing LHC experimental data.

  3. Relativistic AGN jets II. Jet properties and mixing effects for episodic jet activity

    CERN Document Server

    Walg, Sander; Markoff, Sera; Keppens, Rony; Porth, Oliver

    2013-01-01

    Various radio galaxies show signs of having gone through episodic jet outbursts in the past. An example is the class of double-double radio galaxies (DDRGs). However, to follow the evolution of an individual source in real-time is impossible due to the large time scales involved. Numerical studies provide a powerful tool to investigate the temporal behavior of episodic jet outbursts in a (magneto-)hydrodynamical setting. We simulate the injection of two jets from active galactic nuclei (AGN), separated by a short interruption time. Three different jet models are compared. We find that an AGN jet outburst cycle can be divided into four phases. The most prominent phase occurs when the restarted jet is propagating completely inside the hot and inflated cocoon left behind by the initial jet. In that case, the jet-head advance speed of the restarted jet is significantly higher than the initial jet-head. While the head of the initial jet interacts strongly with the ambient medium, the restarted jet propagates almos...

  4. Design and Analysis of Hydraulic Chassis with Obstacle Avoidance Function

    Science.gov (United States)

    Hong, Yingjie; Zhang, Xiang

    2017-07-01

    This article mainly expounds the design of hydraulic system for the hydraulic chassis with obstacle avoidance function. Including the selection of hydraulic motor wheels, hydraulic pump, digital hydraulic cylinder and the matching of engine power. And briefly introduces the principle of obstacle avoidance.

  5. Helical coil thermal hydraulic model

    Science.gov (United States)

    Caramello, M.; Bertani, C.; De Salve, M.; Panella, B.

    2014-11-01

    A model has been developed in Matlab environment for the thermal hydraulic analysis of helical coil and shell steam generators. The model considers the internal flow inside one helix and its associated control volume of water on the external side, both characterized by their inlet thermodynamic conditions and the characteristic geometry data. The model evaluates the behaviour of the thermal-hydraulic parameters of the two fluids, such as temperature, pressure, heat transfer coefficients, flow quality, void fraction and heat flux. The evaluation of the heat transfer coefficients as well as the pressure drops has been performed by means of the most validated literature correlations. The model has been applied to one of the steam generators of the IRIS modular reactor and a comparison has been performed with the RELAP5/Mod.3.3 code applied to an inclined straight pipe that has the same length and the same elevation change between inlet and outlet of the real helix. The predictions of the developed model and RELAP5/Mod.3.3 code are in fairly good agreement before the dryout region, while the dryout front inside the helical pipes is predicted at a lower distance from inlet by the model.

  6. Real vs. simulated relativistic jets

    CERN Document Server

    Gómez, J L; Agudo, I; Marscher, A P; Jorstad, S G; Aloy, M A

    2005-01-01

    Intensive VLBI monitoring programs of jets in AGN are showing the existence of intricate emission patterns, such as upstream motions or slow moving and quasi-stationary componentes trailing superluminal features. Relativistic hydrodynamic and emission simulations of jets are in very good agreement with these observations, proving as a powerful tool for the understanding of the physical processes taking place in the jets of AGN, microquasars and GRBs. These simulations show that the variability of the jet emission is the result of a complex combination of phase motions, viewing angle selection effects, and non-linear interactions between perturbations and the underlying jet and/or ambient medium. Both observations and simulations suggest that shock-in-jet models may be an overly simplistic idealization when interpreting the emission structure observed in actual jets.

  7. Turbulent jet in confined counterflow

    Indian Academy of Sciences (India)

    M Sivapragasam; M D Deshpande; S Ramamurthy; P White

    2014-06-01

    The mean flowfield of a turbulent jet issuing into a confined, uniform counterflow was investigated computationally. Based on dimensional analysis, the jet penetration length was shown to scale with jet-to-counterflow momentum flux ratio. This scaling and the computational results reproduce the well-known correct limit of linear growth of the jet penetration length for the unconfined case when the momentum flux ratio is small. However, for the high momentum flux ratio case corresponding to the confinement, the jet penetration length is shown to reach an asymptotic limit of about 3.57 times the confining duct diameter. This conclusion is contrary to the existing results which predict indefinite growth. A simple modification of an existing similarity solution for the jet in an unconfined counterflow provides a convenient framework for presenting the results of the flowfield and jet penetration length.

  8. Pileup subtraction for jet shapes.

    Science.gov (United States)

    Soyez, Gregory; Salam, Gavin P; Kim, Ji-Hun; Dutta, Souvik; Cacciari, Matteo

    2013-04-19

    Jets in high energy hadronic collisions often contain the fingerprints of the particles that produced them. Those fingerprints, and thus the nature of the particles that produced the jets, can be read off with the help of quantities known as jet shapes. Jet shapes are, however, severely affected by pileup, the accumulation in the detector of the residues of the many simultaneous collisions taking place in the Large Hadron Collider (LHC). We introduce a method to correct for pileup effects in jet shapes. Relative to earlier, limited approaches, the key advance resides in its full generality, achieved through a numerical determination, for each jet, of a given shape's susceptibility to pileup. The method rescues the possibility of using jet shapes in the high pileup environment of current and future LHC running, as we show with examples of quark-gluon discrimination and top tagging.

  9. WATER ENERGY IN HYDROAMELIORATIVE SYSTEMS USING THE HYDRAULIC TRANSFORMER TYPE A. BARGLAZAN AND THE HYDRAULIC HAMMER (HYDRAULIC PUMP

    Directory of Open Access Journals (Sweden)

    Teodor Eugen Man

    2010-01-01

    Full Text Available This paper presents two examples of exploitation of water energy that can be used in the irrigation field. First of theseexamples is the hydraulic transformer type A. Barglazan used for irrigation, pumped water is taken directly from theriver’s well, using a hydraulic pump which simultaneously carried out a double transformation in this way: hydraulicenergy into mechanic energy and mechanical energy into hydraulic energy. Technology preparation and devices designwas done in record time, seeing that this constructive solution is more robust, reliable and with improved energyperformance versus the laboratory prototype. The experimental research which was made at 1:1 scale proved theirgood function over time. Another example is the hydraulic hammer (hydraulic pump that uses low-head energy topump water, with a global efficiency of about 10 - 50%. Currently, the new situation of private ownership of landprovides conditions for new pumping microstations to be made where irrigation is necessary and optimal hydrauliclocations exist.

  10. Expected performance of ATLAS for measurements of jets, b-jets, tau-jets, and ETmis

    CERN Document Server

    Sapinski, M

    2002-01-01

    Jets and missing energy are among the most important objects of LHC physics. The accuracy of measurements of missing energy and direction and energy of jets put strong requirements on the detector performance. These requirements and the ATLAS Calorimeter system which is projected to fulfill these requirements are presented. The jet reconstruction algorithms and jet energy scale calibration are shortly discussed. Forward jet tagging, b-tagging and tau-tagging are important issues of many physical analyses. Reconstruction of resonances is an example of complex use of calorimeter performance

  11. Description of the ATLAS jet veto measurement and jet gap jet events at hadronic colliders

    CERN Document Server

    Royon, C

    2014-01-01

    We present a new QCD description of the ATLAS jet veto measurement, using the Banfi- Marchesini-Smye equation to constrain the inter-jet QCD radiation. This equation resums emis- sions of soft gluons at large angles and leads to a very good description of data. We also investigate jet gap jet events in hadron-hadron collisions, in which two jets are produced and separated by a large rapidity gap. Using a renormalisation-group improved NLL kernel implemented in the HERWIG Monte Carlo program, we show that the BFKL predictions are in good agreement with the Tevatron data, and present predictions that could be tested at the LHC.

  12. HYDRAULIC CHARACTERISTICS OF VERTICAL VORTEX AT HYDRAULIC INTAKES

    Institute of Scientific and Technical Information of China (English)

    CHEN Yun-liang; WU Chao; YE Mao; JU Xiao-ming

    2007-01-01

    The trace of vertical vortex flow at hydraulic intakes is of the shape of spiral lines, which was observed in the presented experiments with the tracer technique. It represents the fluid particles flow spirally from the water surface to the underwater and rotate around the vortex-axis multi-cycle. This process is similar to the movement of screw. To describe the multi-circle spiral characteristics under the axisymmetric condition, the vertical vortex would change not only in the radial direction but also in the axial direction. The improved formulae for three velocity components for the vertical vortex flow were deduced by using the method of separation of variables in this article. In the improved formulae, the velocity components are the functions of the radial and axial coordinates, so the multi-circle spiral flow of vertical vortex could be simulated. The calculated and measured results for the vertical vortex flow were compared and the causes of errors were analyzed.

  13. Imaging flow during impingement of differentially heated jets over a flat surface

    Energy Technology Data Exchange (ETDEWEB)

    Rathee, Yogender; Vinoth, B.R.; Panigrahi, P.K., E-mail: panig@iitk.ac.in; Muralidhar, K.

    2015-12-01

    occurs at the mid-plane location. This is also the location of the peak in RMS wall temperature. Among all velocity ratios, the equal velocity configuration shows the highest RMS wall temperature. Here, PIV imaging shows a recirculation pattern in the time-averaged velocity near the stagnation point. When the flow rates are unequal, the higher velocity jet provides a blanket on the lower velocity side. The wall temperature fluctuations depend on the interaction between the cold and the hot jets and the location of the impingement plate.JEL Classification: K. Thermal hydraulics.

  14. Induced drill-spray during hydraulic slotting of a coal seam and its influence on gas extraction

    Institute of Scientific and Technical Information of China (English)

    Shen Chunming; Lin Baiquan; Zhang Qizhi; Yang Wei; Zhang Lianjun

    2012-01-01

    Hydraulic slotting can induce drill spray in a gassy,low permeability coal seam.This then influences subsequent gas extraction.This paper describes the drill spray phenomenon from a mechanical perspective and analyzes the effects of water jet damage during slotting.A simulation of the stresses around the drill hole and slot was prepared using FLAC-3D code.It helps explain the induction of drill spray during hydraulic slotting.The stress concentration around the bore increases as the diameter of the hole increases.As the hole enlarges the variation in stress also increases,which introduces an instability into the coal.This allows easy breaking and removal of the coal.Destruction of the coal structure by the water jet is the major factor causing drill spray.Energy stored as either strain or gas pressure is released by the water jet and this causes the coal to fracture and be expelled from the hole.Field tests showed the effect on gas extraction after slotting with drill spray.The concentration of gas increases after drilling.Compared to conventional techniques,the hydraulic slotted bore gives a gas concentration three times higher and has an effective range twice as far.This makes the gas extraction process more efficient and allows reduced construction effort.

  15. Investigation on the influence of leakage clearance on the flow field and performance of scroll hydraulic pump

    Science.gov (United States)

    Sun, Shuaihui; Huang, Yi; Guo, Pengcheng; Zuo, Juanli; Luo, Xingqi

    2016-11-01

    In the present paper, the computer fluid dynamics(CFD) with dynamic mesh model had been applied in scroll hydraulic pump to obtain its flow field at different leakage clearance. The fluid force on the orbiting scroll, the mass flow rate and the hydraulic efficiency at different leakage clearance were calculated based on the flow field data. The results indicated that when the leakage clearance increased from 0.5mm to 1.5mm, the average pressure, maximum of pressure fluctuation, leakage jet flow velocity, shaft power, cavitation degree decreased and the leakage flow rate increased. If the leakage clearance was 2.0mm, the high pressure discharge fluid flowed through the clearance and led to the increase of the average pressure and fluid force. When the leakage clearance is 1.0mm, the average pressure is far lower than that at the 0.5mm clearance, and the hydraulic efficiency is the highest.

  16. Design of Pumps for Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Klit, Peder; Olsen, Stefan; Bech, Thomas Nørgaard

    1999-01-01

    This paper considers the development of two pumps for water hydraulic applications. The pumps are based on two different working principles: The Vane-type pump and the Gear-type pump. Emphasis is put on the considerations that should be made to account for water as the hydraulic fluid.......KEYWORDS: water, pump, design, vane, gear....

  17. Hydraulic fracturing with distinct element method

    NARCIS (Netherlands)

    Pruiksma, J.P.; Bezuijen, A.

    2002-01-01

    In this report, hydraulic fracturing is investigated using the distinct element code PFC2D from Itasca. Special routines were written to be able to model hydraulic fracturing. These include adding fluid flow to PFC2D and updating the fluid flow domains when fractures appear. A brief description of t

  18. Hydraulic Actuator for Ganged Control Rods

    Science.gov (United States)

    Thompson, D. C.; Robey, R. M.

    1986-01-01

    Hydraulic actuator moves several nuclear-reactor control rods in unison. Electromagnetic pump pushes liquid lithium against ends of control rods, forcing them out of or into nuclear reactor. Color arrows show lithium flow for reactor startup and operation. Flow reversed for shutdown. Conceived for use aboard spacecraft, actuator principle applied to terrestrial hydraulic machinery involving motion of ganged rods.

  19. Control arrangement for the actuation of hydraulic consumers

    Energy Technology Data Exchange (ETDEWEB)

    Kussel, W.; Dettmers, M.; Weirich, W.

    1988-11-09

    An arrangement for controlling the actuation of hydraulic consumers, by selectively connecting the consumers to hydraulic pressure and return lines; the control arrangement comprising a respective hydraulically operated directional control valve associated with each of the hydraulic consumers, a respective electro-magnetically operated pre-control valve associated with each of the hydraulic directional control valves, and further electro-magnetically operated directional control valve means associated with the pre-control valves, each of the hydraulic consumers being connectible to the hydraulic pressure or return lines via the associated hydraulically operated directional control valve which is actuatable by a hydraulic control line leading from the output of the associated pre-control valve, wherein the inputs of the pre-control valves are connected directly to the hydraulic return line and indirectly, via the further control valve means, to the hydraulic return line or to a hydraulic control pressure line.

  20. Gravity-Driven Hydraulic Fractures

    Science.gov (United States)

    Germanovich, L. N.; Garagash, D.; Murdoch, L. C.; Robinowitz, M.

    2014-12-01

    This study is motived by a new method for disposing of nuclear waste by injecting it as a dense slurry into a hydraulic fracture that grows downward to great enough depth to permanently isolate the waste. Disposing of nuclear waste using gravity-driven hydraulic fractures is mechanically similar to the upward growth of dikes filled with low density magma. A fundamental question in both applications is how the injected fluid controls the propagation dynamics and fracture geometry (depth and breadth) in three dimensions. Analog experiments in gelatin [e.g., Heimpel and Olson, 1994; Taisne and Tait, 2009] show that fracture breadth (the short horizontal dimension) remains nearly stationary when the process in the fracture "head" (where breadth is controlled) is dominated by solid toughness, whereas viscous fluid dissipation is dominant in the fracture tail. We model propagation of the resulting gravity-driven (buoyant or sinking), finger-like fracture of stationary breadth with slowly varying opening along the crack length. The elastic response to fluid loading in a horizontal cross-section is local and can be treated similar to the classical Perkins-Kern-Nordgren (PKN) model of hydraulic fracturing. The propagation condition for a finger-like crack is based on balancing the global energy release rate due to a unit crack extension with the rock fracture toughness. It allows us to relate the net fluid pressure at the tip to the fracture breadth and rock toughness. Unlike the PKN fracture, where breadth is known a priori, the final breadth of a finger-like fracture is a result of processes in the fracture head. Because the head is much more open than the tail, viscous pressure drop in the head can be neglected leading to a 3D analog of Weertman's hydrostatic pulse. This requires relaxing the local elasticity assumption of the PKN model in the fracture head. As a result, we resolve the breadth, and then match the viscosity-dominated tail with the 3-D, toughness

  1. SparkJet Efficiency

    Science.gov (United States)

    Golbabaei-Asl, Mona; Knight, Doyle; Anderson, Kellie; Wilkinson, Stephen

    2013-01-01

    A novel method for determining the thermal efficiency of the SparkJet is proposed. A SparkJet is attached to the end of a pendulum. The motion of the pendulum subsequent to a single spark discharge is measured using a laser displacement sensor. The measured displacement vs time is compared with the predictions of a theoretical perfect gas model to estimate the fraction of the spark discharge energy which results in heating the gas (i.e., increasing the translational-rotational temperature). The results from multiple runs for different capacitances of c = 3, 5, 10, 20, and 40 micro-F show that the thermal efficiency decreases with higher capacitive discharges.

  2. Jet Physics in ATLAS

    CERN Document Server

    Sandoval, C; The ATLAS collaboration

    2012-01-01

    Measurements of hadronic jets provide tests of strong interactions which are interesting both in their own right and as backgrounds to many New Physics searches. It is also through tests of Quantum Chromodynamics that new physics may be discovered. The extensive dataset recorded with the ATLAS detector throughout the 7 TeV and 8 TeV centre-of-mass LHC operation periods allows QCD to be probed at distances never reached before. We present a review of selected ATLAS jet physics measurements. These measurements constitute precision tests of QCD in a new energy regime, and show sensitivity to the parton densities in the proton and to the value of the strong coupling, alpha_s.

  3. Astrophysical Jets and Outflows

    CERN Document Server

    De Gouveia dal Pino, E M

    2004-01-01

    Highly collimated supersonic jets and less collimated outflows are observed to emerge from a wide variety of astrophysical objects. They are seen in young stellar objects (YSOs), proto-planetary nebulae, compact objects (like galactic black holes or microquasars, and X-ray binary stars), and in the nuclei of active galaxies (AGNs). Despite their different physical scales (in size, velocity, and amount of energy transported), they have strong morphological similarities. What physics do they share? These systems either hydrodynamic or magnetohydrodynamic (MHD) in nature and are, as such, governed by non-linear equations. While theoretical models helped us to understand the basic physics of these objects, numerical simulations have been allowing us to go beyond the one-dimensional, steady-state approach extracting vital information. In this lecture, the formation, structure, and evolution of the jets are reviewed with the help of observational information, MHD and purely hydrodynamical modeling, and numerical si...

  4. Scaling hydraulic properties of a macroporous soil

    Science.gov (United States)

    Mohanty, Binayak P.

    1999-06-01

    Macroporous soils exhibit significant differences in their hydraulic properties for different pore domains. Multimodal hydraulic functions may be used to describe the characteristics of multiporosity media. I investigated the usefulness of scaling to describe the spatial variability of hydraulic conductivity (K(-h)) functions of a macroporous soil in Las Nutrias, New Mexico. Piecewise-continuous hydraulic conductivity functions suitable for macroporous soils in conjunction with a hybrid similar media-functional normalization scaling approach were used. Results showed that gravity-dominated flow and the related hydraulic conductivity (K(minus;h) functions of the macropore region are more readily scalable than capillary-dominated flow properties of the mesopore and micropore regions. A possible reason for this behavior is that gravity-dominated flow in the larger pores is mostly influenced by the pore diameter which remains more uniform as compared to tortuous mesopores and micropores with variable neck and body sizes along the pore length.

  5. Hydraulic conductivity of GCLs in MSW landfills

    Institute of Scientific and Technical Information of China (English)

    LI Guo-cheng; YANG Wu-chao; DAN Tang-hui

    2008-01-01

    The state of the art of the study on the hydraulic conductivity of GCLs is presented in terms of the in-fluence of the effective stress, chemical interactions, freeze - thaw cycles and temperature gradients. The chan-ges of void ratio caused by changes of effective stress have a direct linear effect on the hydraulic conductivity, regardless of the cation concentration or the thickness of the adsorbed layer. The hydraulic conductivity is relat-ed to the relative abundance of monovalent and divalent cation(RMD), and RMD has a great effect on the hy-draulic conductivity in weak solution. The long-term susceptibility of GCLs to increased hydraulic conductivity as a response to repeated freeze-thaw cycling is minimal, which has been proved after 150 freeze-thaw cycles. The potential of desiccation cracking increases with the increasing temperature gradient and is related to the ini-tial subsoil water content, the applied overburden stress, etc.

  6. Modeling and Simulation of Hydraulic Engine Mounts

    Institute of Scientific and Technical Information of China (English)

    DUAN Shanzhong; Marshall McNea

    2012-01-01

    Hydraulic engine mounts are widely used in automotive powertrains for vibration isolation.A lumped mechanical parameter model is a traditional approach to model and simulate such mounts.This paper presents a dynamical model of a passive hydraulic engine mount with a double-chamber,an inertia track,a decoupler,and a plunger.The model is developed based on analogy between electrical systems and mechanical-hydraulic systems.The model is established to capture both low and high frequency dynatmic behaviors of the hydraulic mount.The model will be further used to find the approximate pulse responses of the mounts in terms of the force transmission and top chamber pressure.The close form solution from the simplifiod linear model may provide some insight into the highly nonlinear behavior of the mounts.Based on the model,computer simulation has been carried out to study dynamic performance of the hydraulic mount.

  7. Vortices catapult droplets in atomization

    CERN Document Server

    Jerome, J John Soundar; Matas, Jean-Philippe; Zaleski, Stéphane; Hoepffner, Jérôme

    2016-01-01

    A droplet ejection mechanism in planar two-phase mixing layers is examined. Any disturbance on the gas-liquid interface grows into a Kelvin-Helmholtz wave, and the wave crest forms a thin liquid film that flaps as the wave grows downstream. Increasing the gas speed, it is observed that the film breaks up into droplets which are eventually thrown into the gas stream at large angles. In a flow where most of the momentum is in the horizontal direction, it is surprising to observe these large ejection angles. Our experiments and simulations show that a recirculation region grows downstream of the wave and leads to vortex shedding similar to the wake of a backward-facing step. The ejection mechanism results from the interaction between the liquid film and the vortex shedding sequence: a recirculation zone appears in the wake of the wave and a liquid film emerges from the wave crest; the recirculation region detaches into a vortex and the gas flow over the wave momentarily reattaches due to the departure of the vor...

  8. Linearized model for the hydrodynamic stability investigation of molten fuel jets into the coolant of a Liquid Metal Fast Breeder Reactor (LMFBR)

    Science.gov (United States)

    Hartel, K.

    1986-02-01

    The hydrodynamic stability of liquid jets in a liquid continuum, both characterized by low viscosity was analyzed. A linearized mathematical model was developed. This model enables the length necessary for fragmentation of a vertical, symmetric jet of molten fuel by hydraulic forces in the coolant of a liquid metal fast breeder reactor to be evaluated. On the basis of this model the FRAG code for numerical calculation of the hydrodynamic fragmentation mechanism was developed.

  9. Hydraulic slotting technology to prevent coal and gas outburst during heading excavation

    Energy Technology Data Exchange (ETDEWEB)

    Wei, G.; Guo, Z.; Xie, L.; Xin, X.; Shan, Z. [Henan Polytechnic University, Jiaozuo (China)

    2007-02-15

    The technology of measures to prevent coal and gas outburst was analyzed in serious outburst coal seam under research and experiments in real situations. A new measure, called hydraulic slotting, was described and studied in detail. The characteristic parameters of hydraulic slotting was given in the Jiaozuo mining area and the characteristics of validity, adaptability and security were evaluated. The research results show that slotting heading by high pressure large diameter jet releases not only the stress surrounding the strata but also the gas in coal seam is revealed. The resistance to coal and gas outburst was increased dramatically at once if the area of the slot was big enough. The experimentation succeeded in a 2000 m heading excavation and prevented coal and gas outburst. The heading driving speed was more than doubled. 6 refs., 3 figs., 3 tabs.

  10. 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...

  11. 舰载无人机与弹射装置适配性问题研究%Study on Adaptability of Carrier-based Unmanned Aircraft with Aircraft Catapult Device

    Institute of Scientific and Technical Information of China (English)

    许云飞; 陈良

    2016-01-01

    The adaptability of carrier-based aircraft with aircraft catapult device is composed of machinery interface adaptability, operation process adaptability, take-off capability adaptability and environment condition adaptability in terms of engineering. Carrier-based unmanned aircraft has some unique features compared with common carrier-based aircraft in which be told issues, because it has been constricted by some factors such as requirements, technology level and cost. Chinese industry is a junior in application and design for carrier-based aircraft. This paper discussed features of adaptability of carrier-based aircraft with aircraft catapult device. As well as it believes that discussion could promote the technology readiness level up.%从工程角度,舰载机与弹射装置的适配性由机械接口适配性、操作流程适配性、起飞(含性能)适配性和环境适应性等4个方面构成。舰载无人机作为舰载机的一个分支,受到需求、技术成熟度与成本等多因素影响或制约,在上述4个方面与有人驾驶的舰载机相比,具有其特殊性。我国在舰载机特别是可被弹射起飞的舰载机设计领域仍处于初级阶段,本文针对舰载无人机与弹射装置的适配性进行讨论,以提高未来舰载无人机研制中相关技术的成熟度,加快型号研制进展。

  12. Jet-Environment Interactions as Diagnostics of Jet Physics

    Science.gov (United States)

    Heinz, Sebastian

    2014-09-01

    In this chapter, we will explore the interaction of jets with their environments. Jets can transport a sizable fraction of accretion energy away from black holes and neutron stars. Because they are collimated, they can travel to distances far beyond the gravitational sphere of influence of the black hole. Yet, their interaction with the interstellar and intergalactic medium must eventually halt their advance and dissipate the energy they carry. The termination of the jet, and the inflation of large scale cavities of relativistic plasma offers one of the most powerful ways to constrain the physics of jets. In this chapter, we will review the inflation of radio lobes, the propagation of hot spots, the creation of shells and cavities, and the bending of jet by proper motion through their environment, both in the context of AGN jets and microquasars.

  13. Micromachined chemical jet dispenser

    Energy Technology Data Exchange (ETDEWEB)

    Swierkowski, S.; Ciarlo, D.

    1996-05-13

    Goal is to develop a multi-channel micromachined chemical fluid jet dispenser that is applicable to prototype tests with biological samples that demonstrate its utility for molecular biology experiments. Objective is to demonstrate a new device capable of ultrasonically ejecting droplets from 10-200 {mu}m diameter capillaries that are arranged in an array that is linear or focused. The device is based on several common fabrication procedures used in MEMS (micro electro mechanical systems) technology: piezoelectric actuators, silicon, etc.

  14. Hydraulic test for evaluation of hydrophone VSP

    Energy Technology Data Exchange (ETDEWEB)

    Yabuuchi, Satoshi; Koide, Kaoru [Power Reactor and Nuclear Fuel Development Corp., Toki, Gifu (Japan). Tono Geoscience Center

    1997-12-01

    This hydraulic test was carried out at the test site of Tono Geoscience Center, Mizunami-shi, Gifu Pref. in order to evaluate the reliability of the hydraulic conductivity estimated from hydrophone VSP experiment. From March to April 1997, we carried out measurements of pore-water pressure at five depths and permeability tests at seven depths down to G.L.-300m, within a borehole drilled in granitic rock. We compared the results of hydraulic test with hydrophone VSP experiment on condition that a single open fracture existed, and we obtained two notable results. First, for the granitic rock at which a single open fracture was found by BTV and also detected by hydrophone VSP experiment, the hydraulic conductivity was 1.54 x 10{sup -7} cm/sec, while for the same granitic rock at which another single open fracture was found by BTV but not detected by hydrophone VSP experiment, the hydraulic conductivity was less than 6 x 10{sup -10} cm/sec. Second, we converted the hydraulic conductivity of 1.54 x 10{sup -7} cm/sec which was obtained in a hydraulic test section of length 2.5 m into an equivalent value for a single open fracture of width 1 mm. The converted value (3.8 x 10{sup -4} cm/sec) was similar to the hydraulic conductivity estimated from hydrophone VSP experiment. In conclusion, the hydraulic test result shows that hydrophone VSP is useful to estimate an approximate hydraulic conductivity of a single open fracture. (author)

  15. 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...

  16. Astrophysical jets and outflows

    Science.gov (United States)

    de Gouveia Dal Pino, Elisabete M.

    Highly collimated supersonic jets and less collimated outflows are observed to emerge from a wide variety of astrophysical objects. They are seen in young stellar objects (YSOs), proto-planetary nebulae, compact objects (like galactic black holes or microquasars, and X-ray binary stars), and in the nuclei of active galaxies (AGNs). Despite their different physical scales (in size, velocity, and amount of energy transported), they have strong morphological similarities. What physics do they share? These systems are either hydrodynamic or magnetohydrodynamic (MHD) in nature and are, as such, governed by non-linear equations. While theoretical models helped us to understand the basic physics of these objects, numerical simulations have been allowing us to go beyond the one-dimensional, steady-state approach extracting vital information. In this lecture, the formation, structure, and evolution of the jets are reviewed with the help of observational information, MHD and purely hydrodynamical modeling, and numerical simulations. Possible applications of the models particularly to YSOs and AGN jets are addressed.

  17. DLC coatings for hydraulic applications

    Institute of Scientific and Technical Information of China (English)

    Luca NOBILI; Luca MAGAGNIN

    2009-01-01

    Replacement of lubricating oils with water or low-viscosity fluids is highly desirable in many industrial fields, on account of the environmental and economical advantages. Low lubricity of water might be insufficient for proper operation of hydraulic components, and diamond-like carbon(DLC) coatings are very attractive as solid lubricant films. A remote-plasma PACVD process was utilized to deposit hydrogenated DLC coatings (a-C:H) on different substrates. Microindentation measurements show that the coating hardness is around 35 GPa. Tribological behavior was evaluated by block-on-ring tests performed in water and water with alumina. The wear rate was calculated after measuring the wear volume by a laser profilemeter. Morphological and compositional analysis of the wear tracks reveal that coating failure may occur by abrasive wear or delamination, depending on the substrate properties. Hard and smooth substrates give the best results and dispersed alumina particles increase the wear rate.

  18. Aircraft Hydraulic Systems Dynamic Analysis

    Science.gov (United States)

    1978-10-01

    4400 PSIG OUTLET PRESSURE ~’f UM5 S1 l .( FIF ~0RV lR 1 .I. AP (c R (V) IFWM) APPROX C ASE !VPý :iI S ReUN N•;MRF.. r p kN i t, isI A! f IN, I:E • ’l...and 1F.GI pump modelo were assumed from data supplied by CECO. 165 _ -- --- - SECTION V HYDRAULIC MOTOR MODEL DEVELOPMENT AND VERIFICATION A fixed...3 70 P.,0 601 ~4 M24.0 3 1p ’, 4 r I 1 1 ISIS 2411 APPENDIX E (CONT.) HSFR TECHNICAL MANUAL (AFAPL-TR-76-43, VOL. IV) 4.15 VANE PU`MP SUBROUTINE 4.15A

  19. Environmental Assessment for Installation of a New Jet Engine Test Cell, Edwards Air Force Base, California

    Science.gov (United States)

    2012-09-01

    processes, the operation of internal combustion engines (e.g., auxiliary ground equipment, boilers, turbine engines, etc.) and adhesives /sealant...include jet and motor fuel, other types of petroleum products, paints, thinners, adhesives , cleaners, lead-acid batteries, hydraulic fluids and...of the recorded specimens consist of isolated fragments of tooth enamel or bone that are not securely dated. Irvingtonian fossil localities have

  20. Design and analysis of electrogas(hydro)dynamic converters with electrohydrodynamic jet turbulization

    Energy Technology Data Exchange (ETDEWEB)

    Nagornyi, V.S.

    1986-09-01

    The principles of the design of electropneumatic and electrohydraulic converters with the turbulization of a submerged jet by a directional ion flux in an electric field are examined. A mathematical model is developed for calculating the static characteristics of electrohydrodynamic (EHD) converters of signal energy. It is shown that the same design base can be used for the EHD conversion of an electric signal to either a pneumatic or a hydraulic signal. 7 references.

  1. 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.

  2. Wall jets created by single and twin high pressure jet impingement

    Science.gov (United States)

    Miller, P.; Wilson, M.

    1993-03-01

    An extensive experimental investigation into the nature of the wall jets produced by single and twin normal jet impingement has been undertaken. Wall jet velocity profiles have been recorded up to 70 jet diameters from the impingement point, at pressures representative of current VStol technology. The tests used fixed convergent nozzles, with nozzle height and spacing and jet pressure being varied. Single jet impingement displays a consistent effect of nozzle height on wall jet development. For twin jet cases a powerful reinforcement exists along the wall jet interaction plane. Remote from the interaction plane the wall jets are weaker than those produced by a single jet impingement.

  3. The use of Regression Triplet in Hydraulic Modelling on the Example of Determination of Overfall Coefficient

    Directory of Open Access Journals (Sweden)

    Petr Pelikán

    2016-01-01

    Full Text Available The paper is focused on a hydraulic problem of water overfall on hydrotechnic structures, especially outlets and spillways of water reservoirs. The main parameter of such structures is its discharge capacity depending on overfall coefficient, dimensions of spillway, gravitational constant and height of overflowing water jet. The aim of investigation was the mathematical derivation of formula for calculation of overfall coefficient for sharp-crested spillway from observed data. The problem was solved with the aid of statistical method of nonlinear regression analysis, Gauss-Newton algorithm (nonlinear least squares. The objective of investigation was achieved by the design of new equation providing high confidential results.

  4. Decelerating relativistc two-component jets

    NARCIS (Netherlands)

    Meliani, Z.; Keppens, R.

    2009-01-01

    Transverse stratification is a common intrinsic feature of astrophysical jets. There is growing evidence that jets in radio galaxies consist of a fast low-density outflow at the jet axis, surrounded by a slower, denser, extended jet. The inner and outer jet components then have a different origin

  5. Decelerating relativistic two-component jets

    NARCIS (Netherlands)

    Meliani, Z.; Keppens, R.

    2009-01-01

    Transverse stratification is a common intrinsic feature of astrophysical jets. There is growing evidence that jets in radio galaxies consist of a fast low-density outflow at the jet axis, surrounded by a slower, denser, extended jet. The inner and outer jet components then have a different origin

  6. Decelerating relativistic two-component jets

    NARCIS (Netherlands)

    Meliani, Z.; Keppens, R.

    2009-01-01

    Transverse stratification is a common intrinsic feature of astrophysical jets. There is growing evidence that jets in radio galaxies consist of a fast low-density outflow at the jet axis, surrounded by a slower, denser, extended jet. The inner and outer jet components then have a different origin an

  7. Decelerating relativistc two-component jets

    NARCIS (Netherlands)

    Meliani, Z.; Keppens, R.

    2009-01-01

    Transverse stratification is a common intrinsic feature of astrophysical jets. There is growing evidence that jets in radio galaxies consist of a fast low-density outflow at the jet axis, surrounded by a slower, denser, extended jet. The inner and outer jet components then have a different origin an

  8. Control of a Circular Jet

    CERN Document Server

    Gohil, Trushar B; Muralidhar, K

    2010-01-01

    The present study report direct numerical simulation (DNS) of a circular jet and the effect of a large scale perturbation at the jet inlet. The perturbation is used to control the jet for increased spreading. Dual-mode perturbation is obtained by combining an axisymmetric excitation with the helical. In the fluid dynamics videos, an active control of the circular jet at a Reynolds number of 2000 for various frequency ratios (both integer and non-integer) has been demonstrated. When the frequency ratio is fixed to 2, bifurcation of the jet on a plane is evident. However, for a non-integer frequency ratio, the axisymmetric jet is seen to bloom in all directions.

  9. 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.

  10. Material Transport with Air Jet

    Directory of Open Access Journals (Sweden)

    István Patkó

    2005-11-01

    Full Text Available In the field of industry, there are only a very few examples of material transportwith air jet, and one of these is the air jet loom. In this weaving technology, the weft (thetransversal yarn of the fabric is shot by air jet. This paper will set up the mathematicalmodel of yarn end movement. For a special case, I will specify a solution of the model.

  11. CFD simulation of steam–air jet condensation

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Xiao-hang [School of Energy and Power Engineering, Shandong University, Jinan 250061, Shandong (China); Sui, Hui [Shandong Laigang Energy Conservation and Environmental Protection Engineering Co., Ltd, Laiwu 271133, Shandong (China); Tian, Mao-cheng, E-mail: tianmc65@sdu.edu.cn [School of Energy and Power Engineering, Shandong University, Jinan 250061, Shandong (China)

    2016-02-15

    Highlights: • Steam–air mixture jet direct contact condensation behavior is studied numerically. • Euler–Euler two-fluid model and species model are coupled to simulated jet condensation. • Thermal phase change model is used to account for interphase mass transfer. • Gas volume fraction from simulation is corrected for comparison with experiment. • Temperature and gas volume fraction distributions agree reasonably with experimental results. - Abstract: A three dimensional model was established based on Euler–Euler two-fluid model to simulate the steam jet direct contact condensation with air involved. Condensation of steam in the gas mixture was realized using thermal phase change model. Species transport equation for the gas phase was employed to account for composition variation of the steam air mixture. The investigated gas mass flux at nozzle exit was within 300 kg/m{sup 2}/s, with non-condensable air of less than 10%. Numerical results show the steam in gas plume condenses rapidly after leaving the nozzle, until only air and a little uncondensed steam remain in the gas plume. The addition of air in the jet deteriorates the condensation heat transfer, leading temperature and void fraction around the nozzle to decrease more slowly in both axial and radial directions. Five cases of experimental results were demonstrated with three of them validating the temperature distribution and two of them validating the void fraction. The comparison between numerical and experimental results demonstrates the CFD model can predict the steam–air jet condensation process quite reasonably.Classification: K. Thermal hydraulics.

  12. Active Region Jets II: Triggering and Evolution of Violent Jets

    Science.gov (United States)

    Sterling, Alphonse C.; Moore, Ronald L.; Falconer, David; Panesar, Navdeep K.; Martinez, Francisco

    2017-08-01

    We study a series of X-ray-bright, rapidly evolving active-region coronal jets outside the leading sunspot of AR 12259, using Hinode/XRT, SDO/AIA and HMI, and IRIS/SJ data. The detailed evolution of such rapidly evolving “violent” jets remained a mystery after our previous investigation of active region jets (Sterling et al. 2016, ApJ, 821, 100). The jets we investigate here erupt from three localized subregions, each containing a rapidly evolving (positive) minority-polarity magnetic-flux patch bathed in a (majority) negative-polarity magnetic-flux background. At least several of the jets begin with eruptions of what appear to be thin (thickness ˜Nature, 523, 437). For some jets strands are difficult/ impossible to detect, perhaps due to their thinness, obscuration by surrounding bright or dark features, or the absence of erupting cool-material minifilaments in those jets. Tracing in detail the flux evolution in one of the subregions, we find bursts of strong jetting occurring only during times of strong flux cancelation. Averaged over seven jetting episodes, the cancelation rate was ~1.5×10^19 Mx/hr. An average flux of ~5×10^18 Mx canceled prior to each episode, arguably building up ~10^28—10^29 ergs of free magnetic energy per jet. From these and previous observations, we infer that flux cancelation is the fundamental process responsible for the pre-eruption buildup and triggering of at least many jets in active regions, quiet regions, and coronal holes.

  13. Jet Suppression Measured in ATLAS

    CERN Document Server

    Citron, Zvi Hirsh; The ATLAS collaboration

    2015-01-01

    In relativistic heavy ion collisions, a hot medium with a high density of unscreened color charges is produced, and jets propagating through this medium are known to suffer energy loss. This results in a lower yield of jets emerging from the medium than expected in the absence of medium effects, and thus modifications of the jet yield are directly sensitive to the energy loss mechanism. Furthermore, jets with different flavor content are expected to be affected by the medium in different ways. Parton showers initiated by quarks tend to have fewer fragments carrying a larger fraction of the total jet energy than those resulting from gluons. In this talk, the latest ATLAS results on single jet suppression will be presented. Measurements of the nuclear modification factor, RAA, for fully reconstructed jets are shown. The rapidity dependence of jet suppression is discussed, which is sensitive to the relative energy loss between quark and gluon jets. New measurements of single hadron suppression out to pT~150 GeV ...

  14. The formation of interstellar jets

    Science.gov (United States)

    Tenorio-Tagle, G.; Canto, J.; Rozyczka, M.

    1988-01-01

    The formation of interstellar jets by convergence of supersonic conical flows and the further dynamical evolution of these jets are investigated theoretically by means of numerical simulations. The results are presented in extensive graphs and characterized in detail. Strong radiative cooling is shown to result in jets with Mach numbers 2.5-29 propagating to lengths 50-100 times their original widths, with condensation of swept-up interstellar matter at Mach 5 or greater. The characteristics of so-called molecular outflows are well reproduced by the simulations of low-Mach-number and quasi-adiabatic jets.

  15. Jet physics at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    S. Seidel

    2002-05-29

    Recent analyses by the CDF and D0 Collaborations of jet data produced in p{bar p} collisions at the Fermilab Tevatron Collider are presented. These include new studies of the inclusive jet production cross section, a measurement of the strong coupling constant, the first measurement of subjet multiplicity of quark and gluon jets, examination of ratios of multijet cross sections and their implications for choice of renormalization scale, and a study of charged jet evolution and energy flow in the underlying event. The results are compared to theoretical predictions.

  16. DESIGN AND CONSTRUCTION OF A HYDRAULIC PISTON

    OpenAIRE

    Santos De La Cruz, Eulogio; Universidad Nacional Mayor de San Marcos; Rojas Lazo, Oswaldo; Universidad Nacional Mayor de San Marcos; Yenque Dedios, Julio; Universidad Nacional Mayor de San Marcos; Lavado Soto, Aurelio; Universidad Nacional Mayor de San Marcos

    2014-01-01

    A hydraulic system project includes the design, materials selection and construction of the hydraulic piston, hydraulic circuit and the joint with the pump and its accesories. This equiment will be driven by the force of moving fluid, whose application is in the devices of machines, tools, printing, perforation, packing and others. El proyecto de un sistema hidráulico, comprende el diseño, selección de materiales y construcción del pistón hidráulico, circuito hidráulico y el ensamble con l...

  17. Bubble visualization in a simulated hydraulic jump

    CERN Document Server

    Witt, Adam; Shen, Lian

    2013-01-01

    This is a fluid dynamics video of two- and three-dimensional computational fluid dynamics simulations carried out at St. Anthony Falls Laboratory. A transient hydraulic jump is simulated using OpenFOAM, an open source numerical solver. A Volume of Fluid numerical method is employed with a realizable k-epsilon turbulence model. The goal of this research is to model the void fraction and bubble size in a transient hydraulic jump. This fluid dynamics video depicts the air entrainment characteristics and bubble behavior within a hydraulic jump of Froude number 4.82.

  18. Numerical investigation of mixing in parallel jets

    Energy Technology Data Exchange (ETDEWEB)

    Durve, Ameya [Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019 (India); Patwardhan, Ashwin W., E-mail: aw.patwardhan@ictmumbai.edu.in [Department of Chemical Engineering, Institute of Chemical Technology, Matunga, Mumbai 400019 (India); Banarjee, Indraneel; Padmakumar, G.; Vaidyanathan, G. [Experimental thermal Hydraulics Section, Separation Technology and Hydraulics Division, Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer The effect of adjacent third jet on the mixing of two plane parallel jets is studied using computational fluid dynamics (CFD). Black-Right-Pointing-Pointer Validation of CFD model with experimental data. Black-Right-Pointing-Pointer Comparison of mixing behavior of two jet flow and three jet flow. Black-Right-Pointing-Pointer Three jet systems provide more efficient mixing than single jet and two jet systems. Black-Right-Pointing-Pointer Turbulent fluctuations occurring in the two jet flow are smaller as compared to the three jet flow. - Abstract: A system of parallel jets is widely encountered in many industrial applications. Wide spread applications necessitate the study of the basic mixing phenomenon of parallel jets. In the present study, the mixing phenomenon in the two jet flow and the three jet flow has been studied numerically by solving the Reynolds Averaged Navier Stokes equations. The results predicted by the Reynolds stress model compare well with the experimental data of axial velocity and shear stress available in literature. An attempt has been made to predict the critical mixing regions such as the merge point and the combine point by correlating them with jet spacing and jet exit conditions. A comparison between single jet, two jet and three jet systems has been carried out to evaluate the effect of presence of the second and the third jet on the mixing phenomenon and turbulent fluctuations.

  19. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H. J.; Meliani, Z.; Wijers, R.A.M.J.; Keppens, R.

    2010-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on circumstance

  20. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H. J.; Meliani, Z.; Wijers, Ramj; Keppens, R.

    2011-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on circumstance

  1. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H.J.; Meliani, Z.; Wijers, R.A.M.J.; Keppens, R.

    2012-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on circumstance

  2. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H. J.; Meliani, Z.; Wijers, Ramj; Keppens, R.

    2011-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on

  3. Jet simulations and gamma-ray burst afterglow jet breaks

    NARCIS (Netherlands)

    van Eerten, H. J.; Meliani, Z.; Wijers, R.A.M.J.; Keppens, R.

    2010-01-01

    The conventional derivation of the gamma-ray burst afterglow jet break time uses only the blast wave fluid Lorentz factor and therefore leads to an achromatic break. We show that in general gamma-ray burst afterglow jet breaks are chromatic across the self-absorption break. Depending on

  4. Hydraulic Fracturing and the Environment

    Science.gov (United States)

    Ayatollahy Tafti, T.; Aminzadeh, F.; Jafarpour, B.; de Barros, F.

    2013-12-01

    In this presentation, we highlight two key environmental concerns of hydraulic fracturing (HF), namely induced seismicity and groundwater contamination (GC). We examine the induced seismicity (IS) associated with different subsurface fluid injection and production (SFIP) operations and the key operational parameters of SFIP impacting it. In addition we review the key potential sources for possible water contamination. Both in the case of IS and GC we propose modeling and data analysis methods to quantify the risk factors to be used for monitoring and risk reduction. SFIP include presents a risk in hydraulic fracturing, waste water injection, enhanced oil recovery as well as geothermal energy operations. Although a recent report (NRC 2012) documents that HF is not responsible for most of the induced seismicities, we primarily focus on HF here. We look into vaious operational parameters such as volume and rate of water injection, the direction of the well versus the natural fracture network, the depth of the target and the local stress field and fault system, as well as other geological features. The latter would determine the potential for triggering tectonic related events by small induced seismicity events. We provide the building blocks for IS risk assessment and monitoring. The system we propose will involve adequate layers of complexity based on mapped seismic attributes as well as results from ANN and probabilistic predictive modeling workflows. This leads to a set of guidelines which further defines 'safe operating conditions' and 'safe operating zones' which will be a valuable reference for future SFIP operations. We also illustrate how HF can lead to groundwater aquifer contamination. The source of aquifer contamination can be the hydrocarbon gas or the chemicals used in the injected liquid in the formation. We explore possible pathways of contamination within and discuss the likelihood of contamination from each source. Many of the chemical compounds used

  5. Hadron jets in perspective

    Energy Technology Data Exchange (ETDEWEB)

    Quigg, C.

    1982-11-01

    The subject of hadron jet studies, to judge by the work presented at this workshop, is a maturing field which is still gathering steam. The very detailed work being done in lepton-lepton and lepton-hadron collisions, the second-generation measurements being carried out at Fermilab, the CERN SPS, and the ISR, and the very high energy hard scatterings being observed at the CERN Collider all show enormous promise for increased understanding. Perhaps we shall yet reach that long-sought nirvana in which high-p/sub perpendicular/ collisions become truly simple.

  6. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-gon; Han, Changsoo [Hanyang University, Seoul (Korea, Republic of); Lee, Jong-won [Korea University of Science and Technology, Seoul (Korea, Republic of); Park, Sangdeok [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

    2015-02-15

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

  7. Jet Vectoring Control Using a Novel Synthetic Jet Actuator

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A primary air jet vectoring control system with a novel synthetic jet actuator (SJA) is presented and simulated numerically. The results show that, in comparison with an existing traditional synthetic jet actuator, which is able to perform the duty of either "push" or "pull", one novel synthetic jet actuator can fulfill both "push" and "pull" functions to vector the primary jet by shifting a slide block inside it. Therefore, because the new actuator possesses greater efficiency, it has potentiality to replace the existing one in various applications, such as thrust vectoring and the reduction of thermal signature. Moreover, as the novel actuator can fulfill those functions that the existing one can not, it may well be expected to popularize it into more flow control systems.

  8. Protostellar jets the best laboratories for investigating astrophysical jets

    CERN Document Server

    De Gouveia dal Pino, E M

    1995-01-01

    Highly collimated supersonic jets are observed to emerge from a wide variety of astrophysical objects, ranging from Active Nuclei of Galaxies (AGN's) to Young Stellar Objects (YSOs) within our own Galaxy. Despite their different physical scales (in size, velocity, and amount of energy transported), they have strong morphological similarities. Thanks to the proximity and relatively small timescales, which permit direct observations of evolutionary changes, YSO jets are, perhaps, the best laboratories for cosmic jet investigation. In this lecture, the formation, structure, and evolution of the YSO jets are reviewed with the help of observational information, MHD and purely hydrodynamical modeling, and numerical simulations. Possible applications of the models to AGN jets are also addressed.

  9. Deuteron beam interaction with lithium jet in a neutron source test facility

    Science.gov (United States)

    Hassanein, A.

    1996-10-01

    Testing and evaluating candidate fusion reactor materials in a high-flux, high-energy neutron environment are critical to the success and economic feasibility of a fusion device. The current understanding of materials behavior in fission-like environments and existing fusion facilities is insufficient to ensure the necessary performance of future fusion reactor components. An accelerator-based deuterium—lithium system to generate the required high neutron flux for material testing is considered to be the most promising approach in the near future. In this system, a high-energy (30-40 MeV) deuteron beam impinges on a high-speed (10-20 m/s) lithium jet to produce the high-energy (≥ 14 MeV) neutrons required to simulate a fusion environment via the Li (d, n) nuclear stripping reaction. Interaction of the high-energy deuteron beam and the subsequent response of the high-speed lithium jet are evaluated in detail. Deposition of the deuteron beam, jet-thermal hydraulic response, lithium-surface vaporization rate, and dynamic stability of the jet are modeled. It is found that lower beam kinetic energies produce higher surface temperature and consequently higher Li vaporization rates. Larger beam sizes significantly reduce both bulk and surface temperatures. Thermal expansion and dynamic velocities (normal to jet direction) due to beam energy deposition and momentum transfer are much lower than jet flow velocity and decrease substantially at lower beam current densities.

  10. Parker Hybrid Hydraulic Drivetrain Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Collett, Raymond [Parker-Hannifin Corporation, Cleveland, OH (United States); Howland, James [Parker-Hannifin Corporation, Cleveland, OH (United States); Venkiteswaran, Prasad [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2014-03-31

    This report examines the benefits of Parker Hannifin hydraulic hybrid brake energy recovery systems used in commercial applications for vocational purposes. A detailed background on the problem statement being addressed as well as the solution set specific for parcel delivery will be provided. Objectives of the demonstration performed in high start & stop applications included opportunities in fuel usage reduction, emissions reduction, vehicle productivity, and vehicle maintenance. Completed findings during the demonstration period and parallel investigations with NREL, CALSTART, along with a literature review will be provided herein on this research area. Lastly, results identified in the study by third parties validated the savings potential in fuel reduction of on average of 19% to 52% over the baseline in terms of mpg (Lammert, 2014, p11), Parker data for parcel delivery vehicles in the field parallels this at a range of 35% - 50%, emissions reduction of 17.4% lower CO2 per mile and 30.4% lower NOx per mile (Gallo, 2014, p15), with maintenance improvement in the areas of brake and starter replacement, while leaving room for further study in the area of productivity in terms of specific metrics that can be applied and studied.

  11. Thermal hydraulics development for CASL

    Energy Technology Data Exchange (ETDEWEB)

    Lowrie, Robert B [Los Alamos National Laboratory

    2010-12-07

    This talk will describe the technical direction of the Thermal-Hydraulics (T-H) Project within the Consortium for Advanced Simulation of Light Water Reactors (CASL) Department of Energy Innovation Hub. CASL is focused on developing a 'virtual reactor', that will simulate the physical processes that occur within a light-water reactor. These simulations will address several challenge problems, defined by laboratory, university, and industrial partners that make up CASL. CASL's T-H efforts are encompassed in two sub-projects: (1) Computational Fluid Dynamics (CFD), (2) Interface Treatment Methods (ITM). The CFD subproject will develop non-proprietary, scalable, verified and validated macroscale CFD simulation tools. These tools typically require closures for their turbulence and boiling models, which will be provided by the ITM sub-project, via experiments and microscale (such as DNS) simulation results. The near-term milestones and longer term plans of these two sub-projects will be discussed.

  12. CONTROL OF TWO DIMENSIONAL JETS USING MINIATURE ZERO MASS FLUX JETS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Zero mass flux jets, synthesized by acoustic actuators, have been used for the purpose of jet mixing enhancement and jet vectoring. Zero mass flux jets composed of entirely entrained fluid allow momentum transfer into the embedding flow. In the present experiments, miniature-scale high aspect ratio actuator jets are placed along the long sides and near the exit plane of a primary two-dimensional jet. In different modes, the primary jet can be vectored either towards or away from the actuator jets and the jet mixing is enhanced. The disturbance of the excitation frequency is developed while the unstable frequency of the primary jet is completely suppressed.

  13. Transputer Control of Hydraulic Actuators and Robots

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    Results from a Danish mechatronics research program entitled IMCIA - Intelligent Control and Intelligent Actuators. The objective is development of intelligent actuators for intelligent motion control. A mechatronics test facility with a transputer controlled hydraulic robot suiteable for real...

  14. Concept Evaluation for Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

    2013-01-01

    a suspension system on a car, leading the loads away from the turbine structure. However, to realize a soft hydraulic yaw system a new design concept must be found. As a part of the development of the new concept a preliminary concept evaluation has been conducted, evaluating seven different hydraulic yaw...... concepts, ranging from a one-to-one copy of the electrical drive (electrical drives replaced by hydraulic dittos), to floating suspension systems mounted on hydraulic cylinders. Rough calculations of size and consequences of the different systems are presented ending up with the final concept for further...... investigation. Loads and yaw demands are based on the IEC 61400-1 standard for wind turbine design, and the loads for this examination are extrapolated from the HAWC2 aeroelastic design code. The concepts are based on a 5 MW off-shore turbine....

  15. HYDRAULICS, Des Moines COUNTY, IOWA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  16. ON THE THEORIES OF HYDRAULIC GEOMETRY

    Institute of Scientific and Technical Information of China (English)

    Vijay P. SINGH

    2003-01-01

    Hydraulic geometry is of fundamental importance in planning, design, and management of river engineering and training works. Although some concepts of hydraulic geometry were proposed toward the end of the nineteenth century, the real impetus toward formulating a theory of hydraulic geometry was provided by the work of Leopold and Maddock (1953). A number of theories have since been proposed.Some of the theories are interrelated but others are based on quite different principles. All theories,however, assume that the river flow is steady and uniform and the river tends to attain a state of equilibrium or quasi-equilibrium. The differences are due to the differences in hydraulic mechanisms that the theories employ to explain the attainment of equilibrium by the river.

  17. Stream restoration hydraulic design course: lecture notes

    National Research Council Canada - National Science Library

    Newbury, R

    2002-01-01

    Steam restoration encompasses a broad range of activities and disciplines. This lecture series is designed for practitioners who must fit habitat improvement works in the hydraulics of degraded channels...

  18. Drawing a pictogram operator - hydraulic stowing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Bukhgol' ts, V.P.; Dinershtein, V.A.

    1984-11-01

    Hydraulic stowing is widely used during the extraction of coal from seams prone to spontaneous ignition or from seams situated under preserved structures. Experience has shown that the presence of a considerable number of controlling and measuring devices on hydraulic stowing assemblies results in erratic operations. The authors, after examining the controls of the hydraulic stowing complexes, recommend that all functions which the operator might perform badly or not at all should be controlled automatically. The operator must, however, have access to manual controls which should be included in the system in order to achieve an effective and trouble free operation. The authors propose a pictogram to explain the relationship between the human operator and the hydraulic complex, based on structural diagrams. The system developed, which was tried out at the Koksovaya mine, increased the efficiency of the complex and reduced the work load of the operator. 3 references.

  19. HYDRAULICS, Des Moines COUNTY, IOWA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  20. Hydraulic fracturing chemicals and fluids technology

    CERN Document Server

    Fink, Johannes

    2013-01-01

    When classifying fracturing fluids and their additives, it is important that production, operation, and completion engineers understand which chemical should be utilized in different well environments. A user's guide to the many chemicals and chemical additives used in hydraulic fracturing operations, Hydraulic Fracturing Chemicals and Fluids Technology provides an easy-to-use manual to create fluid formulations that will meet project-specific needs while protecting the environment and the life of the well. Fink creates a concise and comprehensive reference that enables the engineer to logically select and use the appropriate chemicals on any hydraulic fracturing job. The first book devoted entirely to hydraulic fracturing chemicals, Fink eliminates the guesswork so the engineer can select the best chemicals needed on the job while providing the best protection for the well, workers and environment. Pinpoints the specific compounds used in any given fracturing operation Provides a systematic approach to class...

  1. Transputer Control of Hydraulic Actuators and Robots

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    Results from a Danish mechatronics research program entitled IMCIA - Intelligent Control and Intelligent Actuators. The objective is development of intelligent actuators for intelligent motion control. A mechatronics test facility with a transputer controlled hydraulic robot suiteable for real...

  2. 46 CFR 112.50-3 - Hydraulic starting.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hydraulic starting. 112.50-3 Section 112.50-3 Shipping... POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the following: (a) The hydraulic starting system must be...

  3. 21 CFR 870.2780 - Hydraulic, pneumatic, or photoelectric plethysmographs.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydraulic, pneumatic, or photoelectric... § 870.2780 Hydraulic, pneumatic, or photoelectric plethysmographs. (a) Identification. A hydraulic... using hydraulic, pneumatic, or photoelectric measurement techniques. (b) Classification. Class...

  4. RESEARCH OF THE DYNAMIC CHARACTERISTICS ON A NEW HYDRAULIC SYSTEM OF ELECTRO-HYDRAULIC HAMMER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new typed hydraulic system of electro-hydraulic hammer is researched and developed.By means of power bond graphs the modeling and simulation to the dynamic characteristics of the new hydraulic system are performed. The experimental research which is emphasized on the blowing stroke is also performed. It is proved from the result of simulation and experiment that this new hydraulic system possesses such advantages as simplification of structure,flexibleness of operation and reliability of working. Especially it possesses better dynamic characteristics.

  5. Design of a laboratory hydraulic device for testing of hydraulic pumps

    Directory of Open Access Journals (Sweden)

    Pavel Máchal

    2013-01-01

    Full Text Available The present contribution deals with solves problem of research of testing device to monitor of hydrostatic pumps durability about dynamic loading under laboratory conditions. When carrying out the design of testing device are based on load characteristics of tractor hydraulic circuit, the individual characteristics of hydraulic components and performed calculations. Load characteristics on the tractors CASE IH Magnum 310, JOHN DEERE 8100, ZETOR FORTERRA 114 41 and Fendt 926 Vario were measured. Design of a hydraulic laboratory device is based on the need for testing new types of hydraulic pumps or various types of hydraulic fluids. When creating of hydraulic device we focused on testing hydraulic pumps used in agricultural and forestry tractors. Proportional pressure control valve is an active member of the hydraulic device, which provides change of a continuous control signal into relative pressure of operating fluid. The advantage of a designed hydraulic system is possibility of simulation of dynamic operating loading, which is obtained by measurement under real conditions, and thereby creates laboratory conditions as close to real conditions as possible. The laboratory device is constructed at the Department of Transport and Handling, Faculty of Engineering, Slovak University of Agriculture in Nitra.

  6. Momentum transfer by astrophysical jets

    CERN Document Server

    Chernin, L M; De Gouveia dal Pino, E M; Benz, W

    1994-01-01

    We have used 3-D smoothed particle hydrodynamical simulations to study the basic properties of the outflow that is created by a protostellar jet in a dense molecular cloud. The dynamics of the jet/cloud interaction is strongly affected by the cooling in the shocked gas behind the bow shock at the head of the jet. We show that this cooling is very rapid, with the cooling distance of the gas much less than the jet radius. Thus, although ambient gas is initially driven away from the jet axis by the high thermal pressure odf the post-shock gas, rapid cooling reduces the pressure and the outflow subsequently evolves in a momentum-conserving snowplow fashion. The velocity of the ambient gas is high in the vicinity of the jet head, but decreases rapidly as more material is swept up. Thus, this type of outflow produces extremely high velocity clumps of post shock gas which resemble the features seen in outflows. We have investigated the transfer of momentum from the jet to the ambient medium as a function of the jet ...

  7. The Highest Redshift Relativistic Jets

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, C.C.; Stawarz, L.; Siemiginowska, A.; Harris, D.E; Schwartz, D.A.; Wardle, J.F.C.; Gobeille, D.; Lee, N.P.

    2007-12-18

    We describe our efforts to understand large-scale (10's-100's kpc) relativistic jet systems through observations of the highest-redshift quasars. Results from a VLA survey search for radio jets in {approx} 30 z > 3.4 quasars are described along with new Chandra observations of 4 selected targets.

  8. Jet charge at the LHC.

    Science.gov (United States)

    Krohn, David; Schwartz, Matthew D; Lin, Tongyan; Waalewijn, Wouter J

    2013-05-24

    Knowing the charge of the parton initiating a light-quark jet could be extremely useful both for testing aspects of the standard model and for characterizing potential beyond-the-standard-model signals. We show that despite the complications of hadronization and out-of-jet radiation such as pileup, a weighted sum of the charges of a jet's constituents can be used at the LHC to distinguish among jets with different charges. Potential applications include measuring electroweak quantum numbers of hadronically decaying resonances or supersymmetric particles, as well as standard model tests, such as jet charge in dijet events or in hadronically decaying W bosons in tt[over ¯] events. We develop a systematically improvable method to calculate moments of these charge distributions by combining multihadron fragmentation functions with perturbative jet functions and pertubative evolution equations. We show that the dependence on energy and jet size for the average and width of the jet charge can be calculated despite the large experimental uncertainty on fragmentation functions. These calculations can provide a validation tool for data independent of Monte Carlo fragmentation models.

  9. Core shifts in blazar jets

    CERN Document Server

    Zdziarski, Andrzej A; Pjanka, Patryk; Tchekhovskoy, Alexander

    2014-01-01

    We study the effect of core shift in jets, which is the dependence of the position of the jet radio core on the frequency. We derive a new method to measure the jet magnetic field based on both the value of the shift and the observed flux, which compliments the standard method assuming equipartition. Using both methods, we re-analyse the blazar sample of Zamaninasab et al. We find that equipartition is satisfied only if the jet opening angle in the radio core region is close to the values found observationally, $\\simeq$0.1--0.2 divided by the bulk Lorentz factor, $\\Gamma_{\\rm j}$. Larger values, e.g., $1/\\Gamma_{\\rm j}$, would imply very strong departures from equipartition. A small jet opening angle implies in turn the magnetization parameter of $\\ll 1$. We determine the jet magnetic flux taking this effect into account. We find that the average jet magnetic flux is compatible with the model of jet formation due to black-hole spin energy extraction and accretion being magnetically arrested. We calculate the ...

  10. Magnetic Field Topology in Jets

    Science.gov (United States)

    Gardiner, T. A.; Frank, A.

    2000-01-01

    We present results on the magnetic field topology in a pulsed radiative. jet. For initially helical magnetic fields and periodic velocity variations, we find that the magnetic field alternates along the, length of the jet from toroidally dominated in the knots to possibly poloidally dominated in the intervening regions.

  11. Dense Hypervelocity Plasma Jets

    Science.gov (United States)

    Case, Andrew; Witherspoon, F. Douglas; Messer, Sarah; Bomgardner, Richard; Phillips, Michael; van Doren, David; Elton, Raymond; Uzun-Kaymak, Ilker

    2007-11-01

    We are developing high velocity dense plasma jets for fusion and HEDP applications. Traditional coaxial plasma accelerators suffer from the blow-by instability which limits the mass accelerated to high velocity. In the current design blow-by is delayed by a combination of electrode shaping and use of a tailored plasma armature created by injection of a high density plasma at a few eV generated by arrays of capillary discharges or sparkgaps. Experimental data will be presented for a complete 32 injector gun system built for driving rotation in the Maryland MCX experiment, including data on penetration of the plasma jet through a magnetic field. We present spectroscopic measurements of plasma velocity, temperature, and density, as well as total momentum measured using a ballistic pendulum. Measurements are in agreement with each other and with time of flight data from photodiodes and a multichannel PMT. Plasma density is above 10^15 cm-3, velocities range up to about 100 km/s. Preliminary results from a quadrature heterodyne HeNe interferometer are consistent with these results.

  12. LHCb; LHCb Jet Reconstruction

    CERN Multimedia

    Augusto, O

    2012-01-01

    The Large Hadron Collider (LHC) is the most powerful particle accelerator in the world. It has been designed to collide proton beams at an energy up to 14 TeV in the center of mass. In 2011, the data taking was done with a center of mass energy of 7 TeV, the instant luminosity has reached values greater than $4 \\times 10^{32} cm^{-2} s^{-1}$ and the integrated luminosity reached the value of 1.02 $fb^{-1}$ on the LHCb. The jet reconstruction is fundamental to observe events that can be used to test pertubative QCD (pQCD). It also provides a way to observe standard model channels and searches for new physics like SUSY. The anti-kt algorithm is a jet reconstruction algorithm that is based on the distance of the particles on the space $\\eta \\times \\phi$ and on the transverse momentum of particles. To maximize the energy resolution all information about the trackers and the calo...

  13. Characterization of a hydraulically induced bedrock fracture

    OpenAIRE

    2014-01-01

    Hydraulic fracturing is a controversial practice because of concerns about environmental impacts due to its widespread use in recovering unconventional petroleum and natural gas deposits. However, water-only hydraulic fracturing has been used safely and successfully for many years to increase the permeability of aquifers used for drinking and irrigation water supply. This process extends and widens existing bedrock fractures, allowing groundwater storage to increase. Researchers have studied ...

  14. FEEDBACK LINEARISATION APPLIED ON A HYDRAULIC

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik C.;

    2005-01-01

    Generally most hydraulic systems are intrensically non-linear, why applying linear control techniques typically results in conservatively dimensioned controllers to obtain stable performance. Non-linear control techniques have the potential of overcoming these problems, and in this paper the focus...... is on developing and applying several different feedback linearisation (FL) controllers to the individual servo actuators in a hydraulically driven servo robot to evaluate and compare their possiblities and limitations. This is done based on both simulation and experimental results....

  15. Data Analytics of Hydraulic Fracturing Data

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jovan Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Viswanathan, Hari [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hyman, Jeffery [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Middleton, Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-11

    These are a set of slides on the data analytics of hydraulic fracturing data. The conclusions from this research are the following: they proposed a permeability evolution as a new mechanism to explain hydraulic fracturing trends; they created a model to include this mechanism and it showed promising results; the paper from this research is ready for submission; they devised a way to identify and sort refractures in order to study their effects, and this paper is currently being written.

  16. Hydraulic Motor Driving Variable-Pitch System for Wind Turbine

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2013-11-01

    Full Text Available The present hydraulic variable-pitch mechanism of wind turbine uses three hydraulic cylinders to drive three crank and connecting rod mechanisms respectively; the blades are moved with the cranks. The hydraulic variable-pitch mechanism has complex structure, occupies a lot of space and its maintenance is trouble. In order to make up for the shortcomings of hydraulic cylinder variable-pitch system, the present hydraulic variable-pitch mechanism should be changed as follows: hydraulic motors are used to drive gears; gears drive blades; the electro-hydraulic proportional valves are used to control hydraulic motors. The hydraulic control part and electrical control part of variable-pitch system is redesigned. The new variable-pitch system is called hydraulic motor driving variable-pitch system. The new variable-pitch system meets the control requirements of blade pitch, makes the structure simple and its application effect is perfect.    

  17. Elucidating Jet Energy Loss Using Jets: Prospects from ATLAS

    CERN Document Server

    Grau, N

    2009-01-01

    The details of jet energy loss, as measured at RHIC with single particles and mu lti-particle correlations, are unresolved, and new experimental measurements are necessary in order to shed light on the mechanism and behavior of energy loss. Utilizing the ATLAS electromagnetic and hadronic calorimetry, full jet reconstru ction in a heavy ion environment will be performed over a wide range of $p_T$ an d rapidity. With fully reconstructed jets, new and more sensitive probes are ava ilable to test models of energy loss. In this talk, we present a series of obser vables such as the jet $R_{AA}$, the transverse momentum, $j_T$, spectrum of fra gments, the fragmentation function $D(z)$, jet shapes, and di-jet correlations, that aresensitive to perturbative and non-perturbative energy loss. We also disc uss the current level of sensitivity to expected modifications using several dif ferent jet algorithms, the cone, $k_T$, and anti-$k_T$ algorithms.

  18. Microhole High-Pressure Jet Drill for Coiled Tubing

    Energy Technology Data Exchange (ETDEWEB)

    Ken Theimer; Jack Kolle

    2007-06-30

    Tempress Small Mechanically-Assisted High-Pressure Waterjet Drilling Tool project centered on the development of a downhole intensifier (DHI) to boost the hydraulic pressure available from conventional coiled tubing to the level required for high-pressure jet erosion of rock. We reviewed two techniques for implementing this technology (1) pure high-pressure jet drilling and (2) mechanically-assisted jet drilling. Due to the difficulties associated with modifying a downhole motor for mechanically-assisted jet drilling, it was determined that the pure high-pressure jet drilling tool was the best candidate for development and commercialization. It was also determined that this tool needs to run on commingled nitrogen and water to provide adequate downhole differential pressure and to facilitate controlled pressure drilling and descaling applications in low pressure wells. The resulting Microhole jet drilling bottomhole assembly (BHA) drills a 3.625-inch diameter hole with 2-inch coil tubing. The BHA consists of a self-rotating multi-nozzle drilling head, a high-pressure rotary seal/bearing section, an intensifier and a gas separator. Commingled nitrogen and water are separated into two streams in the gas separator. The water stream is pressurized to 3 times the inlet pressure by the downhole intensifier and discharged through nozzles in the drilling head. The energy in the gas-rich stream is used to power the intensifier. Gas-rich exhaust from the intensifier is conducted to the nozzle head where it is used to shroud the jets, increasing their effective range. The prototype BHA was tested at operational pressures and flows in a test chamber and on the end of conventional coiled tubing in a test well. During instrumented runs at downhole conditions, the BHA developed downhole differential pressures of 74 MPa (11,000 psi, median) and 90 MPa (13,000 psi, peaks). The median output differential pressure was nearly 3 times the input differential pressure available from the

  19. Resonance Production in Jet

    CERN Document Server

    Markert, Christina

    2007-01-01

    Hadronic resonances with short life times and strong coupling to the dense medium may exhibit mass shifts and width broadening as signatures of chiral symmetry restoration at the phase transition between hadronic and partonic matter. Resonances with different lifetimes are also used to extract information about the time evolution and temperature of the expanding hadronic medium. In order to collect information about the early stage (at the phase transition) of a heavy-ion collision, resonances and decay particles which are unaffected by the hadronic medium have to be used. We explore a possible new technique to extract signals from the early stage through the selection of resonances from jets. A first attempt of this analysis, using the reconstructed $\\phi$(1020) from 200 GeV Au+Au collisions in STAR, is presented.

  20. Impinging Jet Dynamics

    CERN Document Server

    Chen, Xiaodong

    2012-01-01

    In this fluid dynamics video, Ray-tracing data visualization technique was used to obtain realistic and detailed flow motions during impinging of two liquid jets. Different patterns of sheet and rim configurations were presented to shed light into the underlying physics, including liquid chain, closed rim, open rim, unstable rim and flapping sheet. In addition, stationary asymmetrical waves were observed and compared with existing theories. The generation of stationary capillary wave in respect to the liquid rim were explained by the classic shallow water wave theory. The atomization process caused by development of the impact waves were observed in detail, including fragmentation of liquid sheet, formation of liquid ligaments, and breakup of ligament into droplet. The locking-on feature of the wavelength of impact wave were also found to be similar to that of perturbed free shear layers.

  1. Collection of an electrospinning jet

    Science.gov (United States)

    Han, Tao; Reneker, Darrell

    2006-03-01

    Electrospinning [1, 2] of polymer nanofibers involves an electrically driven bending instability of the elongating jet. If the jet is collected on a stationary surface immediately before or after the bending instability occurs, the jet buckles as it stops. Bending and buckling are distinct phenomena. The determination of the behavior of the jet path in the vicinity of the onset of the first bending instability is important for the orderly collection of the nanofiber. Precise adjustment of the fluid flow, the electrical current, and the shape of the region from which the jet issued, produced a very stable jet which was observed with a high frame rate, short exposure time camera. The fluid jet and the resulting nanofibers were collected on a solid, electrically conducting substrate which was moved laterally, and simultaneously, away from the tip. This collected material preserved a record of the straight segment and the bending and buckling instabilities with a minimum of overlapping. The occurrence of a second bending instability was sometimes observed in the dry fiber. 1. Doshi, J.; Reneker, D.H., Journal of Electrostatics; 35, 151, 1995 2. Reneker, D.H. ;Yarin,A.L.Fong, H.; Koombhongse, S., Journal of Applied Physics, 87, 4531, 2000

  2. Magnetic Dissipation in Relativistic Jets

    Directory of Open Access Journals (Sweden)

    Yosuke Mizuno

    2016-10-01

    Full Text Available The most promising mechanisms for producing and accelerating relativistic jets, and maintaining collimated structure of relativistic jets involve magnetohydrodynamical (MHD processes. We have investigated the magnetic dissipation mechanism in relativistic jets via relativistic MHD simulations. We found that the relativistic jets involving a helical magnetic field are unstable for the current-driven kink instability, which leads to helically distorted structure in relativistic jets. We identified the regions of high current density in filamentary current sheets, indicative of magnetic reconnection, which are associated to the kink unstable regions and correlated to the converted regions of magnetic to kinetic energies of the jets. We also found that an over-pressured relativistic jet leads to the generation of a series of stationary recollimation shocks and rarefaction structures by the nonlinear interaction of shocks and rarefaction waves. The differences in the recollimation shock structure due to the difference of the magnetic field topologies and strengths may be observable through mm-VLBI observations and space-VLBI mission.

  3. Hydraulic Conductivity Anisotropy of Heterogeneous Unsaturated Soils

    Science.gov (United States)

    Sun, Dongmin; Zhu, Jianting

    2010-05-01

    The effects of saturation degree (or capillary pressure) on hydraulic conductivity anisotropy in unsaturated soils have not been fully understood. This study developed an approach based on a conceptualization of combining the neural network based pedo-transfer function (PTF) results with the thin layer concept to explore the capillary pressure-dependent anisotropy in relation to soil texture and soil bulk density. The main objective is to examine how anisotropy characteristics are related to the relationships between hydraulic parameters and the basic soil attributes such as texture and bulk density. The hydraulic parameters are correlated with the texture and bulk density based on the pedo-transfer function (PTF) results. It is demonstrated that non-monotonic behavior of the unsaturated soil anisotropy in relation to the capillary pressure is only observed when the saturated hydraulic conductivity and the shape parameter are both related to the mean particle diameter. When only one hydraulic parameter is related to the grain diameter or when both are not related to the same attribute simultaneously, the unsaturated soil anisotropy increases monotonically with the increasing capillary pressure head. Therefore, it is suggested that this behavior is mainly due to the coupled dependence of the layer saturated hydraulic conductivities and the shape factors on the texture and bulk density. The correlation between the soil grain diameter and bulk density decreases the anisotropy effects of the unsaturated layered soils. The study illustrates that the inter-relationships of soil texture, bulk density, and hydraulic properties may cause vastly different characteristics of anisotropic unsaturated soils.

  4. Flow-Force Compensation in a Hydraulic Valve

    CERN Document Server

    Lugowski, Jan

    2015-01-01

    Flow-reaction forces acting in hydraulic valves have been studied for many decades. Despite this, they are difficult to account for due to the complexities of the jet flow. This paper focuses only on the reduction, also referred to as compensation, of the flow force as applied to a valve spool featuring a profile of a turbine bucket. Fluid power textbooks explain the compensation taking place on such a profile by applying Newton laws of motion to the profile and deliver an equation for the magnitude and the direction of the flow force. This paper shows that both the magnitude and the direction of the compensating flow force are incorrect if calculated from the textbook equation. A corrected analysis of the dynamic forces is presented that are in agreement with earlier experiments by this author. It follows that the compensating flow force should be calculated from the static-pressure imbalance on the spool profile. That is, not Newton but Pascal law should be applied to calculate the compensating flow force.

  5. Geometric Optimization of Hydraulic Rotation Device for Neutron Transmutation Doping

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yongsoo; Kang, Hanok; Park, Kijung; Kim, Seong Hoon; Park, Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The Korea Atomic Energy Research Institute (KAERI) is developing a Hydraulic Rotation Device (HRD) for NTD facilities (NTDHRD) as a part of the Kijang Research Reactor (KJRR) project. This concept has many advantages when compared to the motor driven method, which is currently used in the HANARO research reactor located at KAERI. The OPAL research reactor located at ANSTO has already applied this method. To achieve a constant rotation speed, which is substantial for uniform doping, with a minimal amount of fluid flow, certain geometric requirements should be satisfied. This paper describes the approach we used while determining the number of impulse jet nozzles used to rotate the NTDHRD at a set number of blades as well as the angle of the nozzles of the NTDHRD. The approach that our group has used to geometrically optimize the design of a NTDHRD was described. The adaptation of this approach allows one to predict the required amount of inlet fluid flow and to determine the number of nozzles based on the rule that it should avoid being a divisor of the number of blades, and provides a reference while determining the tile angle of the nozzles. A CFD analysis will be performed as a future study.

  6. 瞬间弹射蒸汽爆破增强离子液体对水稻秸秆的预处理效果%Enhanced effects of ionic liquid pretreatment on rice straw by instant catapult steam explosion

    Institute of Scientific and Technical Information of China (English)

    覃锦程; 郝学密; 刘黎阳; 刘晨光; 白凤武

    2015-01-01

    选取具有不同组分分离效果的离子液体 1-乙基-3-甲基咪唑醋酸盐([Emim]Ac)和 1-乙基-3-甲基咪唑氯盐([Emim]Cl),并联用瞬间弹射蒸汽爆破(instant catapult steam explosion, ICSE)对水稻秸秆进行预处理.离子液体导致了组分的重排,使纤维素更多地暴露于物料表面,同时减弱了木质素对纤维素紧密交联的程度.ICSE的使用提升了离子液体的预处理效果,酶解糖收率比单纯使用离子液体升高了14.83%([Emim]Ac)和13.14%([Emim]Cl),其中ICSE联用[Emim]Ac的糖收率最高达97.00%.采用扫描电镜(SEM)和热重分析仪(TGA)进行物料结构分析,证实了ICSE联用离子液体有助于破坏物料的致密结构,增加无定形区,从而提高酶解糖收率.%In this study, two kinds of ionic liquid, including 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium chloride were used to pretreat rice straw with instant catapult steam explosion (ICSE). The rearrangement of components were caused by ionic liquid pretreatment, which made more cellulose exposed at the surface of rice straw and weakened the cross-link between lignin and cellulose. Through enzymatic hydrolysis analysis, ICSE enhanced the effects of ionic liquid pretreatment by improving the sugar yield. Compared with the sugar yield as using ionic liquid alone, the sugar yield as combination of ICSE and ionic liquid increased by 14.83% ([Emim]Ac) and 13.14% ([Emim]Cl). The highest value reached 97.00% under the pretreatment by ICSE combine with [Emim]Ac. The structural changes were also analyzed by scanning electron microscope (SEM) and thermo gravimetric analysis (TGA). The pretreated materials became more porous with larger amorphous region, and consequently the sugar yield raised.

  7. Jet Grouting. Control of execution and result parameters. Test fields - Experience in Chile; Jet Grouting. Control de parametros de ejecucion y de resultados. Campos de prueba-Experiencia en Chile

    Energy Technology Data Exchange (ETDEWEB)

    Ayarza, P. M.; Vukotic, G.

    2014-07-01

    This article emphasizes the importance of Test Fields in project that includes the Jet Grouting technique. In particular, the Chilean experience is analyzed, where the Jet Grouting was first introduced by Pilots Terratest S. A. in the year 2010, only, only in 2011 the first project using jet columns was constructed. The versatilely of this technique allows its use in a wide variety of projects, for example, soil capacity improvement, settlement control, reduction of soil permeability and other environmental applications. Currently, the most common applications are underpinning existing foundations, ground improvement, lateral support of excavations, hydraulic barriers, slope stabilization, liquefaction control, among others. The Jet Grouting is one of the most demanding soil improvement technique and requires excellence in designing and execution engineers and other involved specialist. It is therefore essential to ensure exhaustive control to the execution and final parameters, in order to check that the product- Jet Grouting element-have the design properties, and implement modifications if necessary. Many authors strongly advises that if there is no comparable experience and even if there is, a Test Field of Jet Grouting elements has to be executed in site. This field consists in a nearby area with similar geotechnical conditions of the project, where Jet Grouting test columns will be constructed. This Test Field will allow selecting the most effective execution parameters and verifying that the final product has he correct design properties. (Author)

  8. Thermal-hydraulic modeling and analysis of hydraulic system by pseudo-bond graph

    Institute of Scientific and Technical Information of China (English)

    胡均平; 李科军

    2015-01-01

    To increase the efficiency and reliability of the thermodynamics analysis of the hydraulic system, the method based on pseudo-bond graph is introduced. According to the working mechanism of hydraulic components, they can be separated into two categories: capacitive components and resistive components. Then, the thermal-hydraulic pseudo-bond graphs of capacitive C element and resistance R element were developed, based on the conservation of mass and energy. Subsequently, the connection rule for the pseudo-bond graph elements and the method to construct the complete thermal-hydraulic system model were proposed. On the basis of heat transfer analysis of a typical hydraulic circuit containing a piston pump, the lumped parameter mathematical model of the system was given. The good agreement between the simulation results and experimental data demonstrates the validity of the modeling method.

  9. Jet energy calibration in ATLAS

    CERN Document Server

    Schouten, Doug

    A correct energy calibration for jets is essential to the success of the ATLAS experi- ment. In this thesis I study a method for deriving an in situ jet energy calibration for the ATLAS detector. In particular, I show the applicability of the missing transverse energy projection fraction method. This method is shown to set the correct mean energy for jets. Pileup effects due to the high luminosities at ATLAS are also stud- ied. I study the correlations in lateral distributions of pileup energy, as well as the luminosity dependence of the in situ calibration metho

  10. Jet performance in Run 2 at ATLAS

    CERN Document Server

    Kunigo, Takuto; The ATLAS collaboration

    2016-01-01

    Slides for the talk "Jet performance in Run 2" at BOOST 2016. In this talk, the jet energy calibration sequence ( including in-situ calibrations at $\\sqrt{s} = 13$ TeV ), jet energy scale and resolution uncertainties and the jet calibration plan for 2016 will be presented.

  11. Jet reconstruction and heavy jet tagging at LHCb

    CERN Document Server

    CERN. Geneva

    2017-01-01

    The jet reconstruction and the heavy jet flavour tagging at LHCb will be discussed with focus on the last published measurements such as the measurement of forward tt, W+bb and W+cc production in pp collisions at √s=8 TeV and the search for the SM Higgs boson decaying in bbbar or ccbar in association to W or Z boson.

  12. Jet charge determination at the LHC

    CERN Document Server

    Tokar, Stano; The ATLAS collaboration

    2017-01-01

    Knowing the charge of the parton initiating a jet could be very useful both for testing different aspects of the Standard model and for searching signals of a beyond-the-standard-model physics. A weighted sum of the charges of a jet constituents can be used at the LHC experiments to distinguish among jets from partons with different charges. A few applications of the jet charge variable are presented here. The jet charge was used to distinguish jets initiated by $b$ quarks from those initiated by $\\bar{b}$ quarks, for distinguishing between boosted hadronically decaying $W^+$ and $W^{-}$, and for distinguishing jets initiated by quarks from those initiated by gluons.

  13. Effect of Natural Fractures on Hydraulic Fracturing

    Science.gov (United States)

    Ben, Y.; Wang, Y.; Shi, G.

    2012-12-01

    Hydraulic Fracturing has been used successfully in the oil and gas industry to enhance oil and gas production in the past few decades. Recent years have seen the great development of tight gas, coal bed methane and shale gas. Natural fractures are believed to play an important role in the hydraulic fracturing of such formations. Whether natural fractures can benefit the fracture propagation and enhance final production needs to be studied. Various methods have been used to study the effect of natural fractures on hydraulic fracturing. Discontinuous Deformation Analysis (DDA) is a numerical method which belongs to the family of discrete element methods. In this paper, DDA is coupled with a fluid pipe network model to simulate the pressure response in the formation during hydraulic fracturing. The focus is to study the effect of natural fractures on hydraulic fracturing. In particular, the effect of rock joint properties, joint orientations and rock properties on fracture initiation and propagation will be analyzed. The result shows that DDA is a promising tool to study such complex behavior of rocks. Finally, the advantages of disadvantages of our current model and future research directions will be discussed.

  14. Microbial effect on soil hydraulic properties

    Science.gov (United States)

    Furman, Alex; Rosenzweig, Ravid; Volk, Elazar; Rosenkranz, Hella; Iden, Sascha; Durner, Wolfgang

    2014-05-01

    Although largely ignored, the soil contains large amount of biofilms (attached microbes) that can affect many processes. While biochemical processes are studied, biophysical processes receive only little attention. Biofilms may occupy some of the pore space, and by that affect the soil hydraulic properties. This effect on unsaturated soils, however, was not intensively studied. In this research we directly measure the hydraulic properties, namely the soil's unsaturated hydraulic conductivity function and retention curve, for soils containing real biofilm. To do that we inoculate soil with biofilm-forming bacteria and incubate it with sufficient amounts of nutrient until biofilm is formed. The hydraulic properties of the incubated soil are then measured using several techniques, including multi-step outflow and evaporation method. The longer measurements (evaporation method) are conducted under refrigeration conditions to minimize microbial activity during the experiment. The results show a clear effect of the biofilm, where the biofilm-affected soil (sandy loam in our case) behaves like a much finer soil. This qualitatively makes sense as the biofilm generates an effective pore size distribution that is characterized by smaller pores. However, the effect is much more complex and needs to be studied carefully considering (for example) dual porosity models. We compare our preliminary results with other experiments, including flow-through column experiments and experiments with biofilm analogues. Clearly a better understanding of the way microbial activity alters the hydraulic properties may help designing more efficient bioremediation, irrigation, and other soil-related processes.

  15. Vibration Isolation for Parallel Hydraulic Hybrid Vehicles

    Directory of Open Access Journals (Sweden)

    The M. Nguyen

    2008-01-01

    Full Text Available In recent decades, several types of hybrid vehicles have been developed in order to improve the fuel economy and to reduce the pollution. Hybrid electric vehicles (HEV have shown a significant improvement in fuel efficiency for small and medium-sized passenger vehicles and SUVs. HEV has several limitations when applied to heavy vehicles; one is that larger vehicles demand more power, which requires significantly larger battery capacities. As an alternative solution, hydraulic hybrid technology has been found effective for heavy duty vehicle because of its high power density. The mechanical batteries used in hydraulic hybrid vehicles (HHV can be charged and discharged remarkably faster than chemical batteries. This feature is essential for heavy vehicle hybridization. One of the main problems that should be solved for the successful commercialization of HHV is the excessive noise and vibration involving with the hydraulic systems. This study focuses on using magnetorheological (MR technology to reduce the noise and vibration transmissibility from the hydraulic system to the vehicle body. In order to study the noise and vibration of HHV, a hydraulic hybrid subsystem in parallel design is analyzed. This research shows that the MR elements play an important role in reducing the transmitted noise and vibration to the vehicle body. Additionally, locations and orientations of the isolation system also affect the efficiency of the noise and vibration mitigation. In simulations, a skyhook control algorithm is used to achieve the highest possible effectiveness of the MR isolation system.

  16. Needle-free jet injections: dependence of jet penetration and dispersion in the skin on jet power.

    Science.gov (United States)

    Schramm-Baxter, Joy; Mitragotri, Samir

    2004-07-07

    Jet injection is a needle-free drug delivery method in which a high-speed stream of fluid impacts the skin and delivers drugs. Although a number of jet injectors are commercially available, especially for insulin delivery, a quantitative understanding of the energetics of jet injection is still lacking. Here, we describe the dependence of jet injections into human skin on the power of the jet. Dermal delivery of liquid jets was quantified using two measurements, penetration of a radiolabeled solute, mannitol, into skin and the shape of jet dispersion in the skin which was visualized using sulforhodamine B (SRB). The power of the jet at the nozzle was varied from 1 to 600 W by independently altering the nozzle diameter (30-560 microm) and jet velocity (100-200 m/s). The dependence of the amount of liquid delivered in the skin and the geometric measurements of jet dispersion on nozzle diameter and jet velocity was captured by a single parameter, jet power. Additional experiments were performed using a model material, polyacrylamide gel, to further understand the dependence of jet penetration on jet power. These experiments demonstrated that jet power also effectively describes gel erosion due to liquid impingement.

  17. Thermal hydraulics characterization of the core and the reactor vessel type BWR; Caracterizacion termohidraulica del nucleo y de la vasija de un reactor tipo BWR

    Energy Technology Data Exchange (ETDEWEB)

    Zapata Y, M.; Lopez H, L.E. [CFE, Carretera Cardel-Nautla Km. 42.5, Municipio Alto Lucero, Veracruz (Mexico)]. e-mail: marxlenin.zapata@cfe.gob.mx

    2008-07-01

    The thermal hydraulics design of a reactor type BWR 5 as the employees in the nuclear power plant of Laguna Verde involves the coupling of at least six control volumes: Pumps jet region, Stratification region, Core region, Vapor dryer region, Humidity separator region and Reactor region. Except by the regions of the core and reactor, these control volumes only are used for design considerations and their importance as operative data source is limited. It is for that is fundamental to complement the thermal hydraulics relations to obtain major data that allow to determine the efficiency of internal components, such as pumps jet, humidity separator and vapor dryer. Like example of the previous thing, calculations are realized on the humidity of the principal vapor during starting, comparing it with the values at the moment incorporated in the data banks of the computers of process of both units. (Author)

  18. Evolution variable dependence of jet substructure

    CERN Document Server

    Sakaki, Yasuhito

    2015-01-01

    Studies on jet substructure have evolved significantly in recent years. Jet substructure is essentially determined by QCD radiations and non-perturbative effects. Predictions of jet substructure are usually different among Monte Carlo event generators, and are governed by the parton shower algorithm implemented. For leading logarithmic parton shower, even though one of the core variables is the evolution variable, its choice is not unique. We examine evolution variable dependence of the jet substructure by developing a parton shower generator that interpolates between different evolution variables using a parameter $\\alpha$. Jet shape variables and associated jet rates for quark and gluon jets are used to demonstrate the $\\alpha$-dependence of the jet substructure. We find angular ordered shower predicts wider jets, while relative transverse momentum ($p_{\\bot}$) ordered shower predicts narrower jets. This is qualitatively in agreement with the missing phase space of $p_{\\bot}$ ordered showers. Such differenc...

  19. A Computational Model of Hydraulic Volume Displacement Drive

    Directory of Open Access Journals (Sweden)

    V. N. Pil'gunov

    2014-01-01

    Full Text Available The paper offers a computational model of industrial-purpose hydraulic drive with two hydraulic volume adjustable working chamber machines (pump and motor. Adjustable pump equipped with the pressure control unit can be run together with several adjustable hydraulic motors on the principle of three-phase hydraulic socket-outlet with high-pressure lines, drain, and drainage system. The paper considers the pressure-controlled hydrostatic transmission with hydraulic motor as an output link. It shows a possibility to create a saving hydraulic drive using a functional tie between the adjusting parameters of the pump and hydraulic motor through the pressure difference, torque, and angular rate of the hydraulic motor shaft rotation. The programmable logic controller can implement such tie. The Coulomb and viscous frictions are taken into consideration when developing a computational model of the hydraulic volume displacement drive. Discharge balance considers external and internal leakages in equivalent clearances of hydraulic machines, as well as compression loss volume caused by hydraulic fluid compressibility and deformation of pipe walls. To correct dynamic properties of hydraulic drive, the paper offers that in discharge balance are included the additional regulated external leakages in the open circuit of hydraulic drive and regulated internal leakages in the closed-loop circuit. Generalized differential equations having functional multipliers and multilinked nature have been obtained to describe the operation of hydraulic positioning and speed drive with two hydraulic volume adjustable working chamber machines. It is shown that a proposed computational model of hydraulic drive can be taken into consideration in development of LS («Load-Sensing» drives, in which the pumping pressure is tuned to the value required for the most loaded slave motor to overcome the load. Results attained can be used both in designing the industrial-purpose heavy

  20. V+jets from CMS

    CERN Document Server

    Zhang, Fengwangdong

    2016-01-01

    This document is dedicated to recent results on the measurements of a vector boson production associated with jets (V+jets) using CMS detector experiment, with a central proton-proton (pp) collision energy of respectively 8 TeV (RunI) and 13 TeV (RunII). The vector boson can be a W boson, Z boson, or photon. The jets are of any flavor, as well as the ones containing heavy flavor quarks, such as bottom(b) quarks. The inclusive cross sections of V+jets processes and differential cross sections as a function of various kinematic observables are presented and compared to several theoretical predictions. In general, the comparison between theoretical calculations and measurement are crucial for improving modeling and precision on QCD dynamics.

  1. Top Jets at the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, L.G.; Lee, S.J.; Perez, G.; Sung, I.; Virzi, J.

    2008-10-06

    We investigatethe reconstruction of high pT hadronically-decaying top quarksat the Large Hadron Collider. One of the main challenges in identifying energetictop quarks is that the decay products become increasingly collimated. This reducesthe efficacy of conventional reconstruction methods that exploit the topology of thetop quark decay chain. We focus on the cases where the decay products of the topquark are reconstructed as a single jet, a"top-jet." The most basic"top-tag" methodbased on jet mass measurement is considered in detail. To analyze the feasibility ofthe top-tagging method, both theoretical and experimental aspects of the large QCDjet background contribution are examined. Based on a factorization approach, wederive a simple analytic approximation for the shape of the QCD jet mass spectrum.We observe very good agreement with the Monte Carlo simulation. We consider high pT tt bar production in the Standard Model as an example, and show that our theoretical QCD jet mass distributions can efficiently characterize the background via sideband analyses. We show that with 25 fb-1 of data, our approach allows us to resolve top-jets with pT _> 1 TeV, from the QCD background, and about 1.5 TeV top-jets with 100 fb-1, without relying on b-tagging. To further improve the significancewe consider jet shapes (recently analyzed in 0807.0234 [hep-ph]), which resolve thesubstructure of energy flow inside cone jets. A method of measuring the top quarkpolarization by using the transverse momentum of the bottom quark is also presented.The main advantages of our approach are: (i) the mass distributions are driven byfirst principle calculations, instead of relying solely on Monte Carlo simulation; (ii) for high pT jets (pT _> 1 TeV), IR-safe jet shape variables are robust against detectorresolution effects. Our analysis can be applied to other boosted massive particlessuch as the electroweak gauge bosons and the Higgs.

  2. Measurement and evaluation of static characteristics of rotary hydraulic motor

    Directory of Open Access Journals (Sweden)

    Hružík Lumír

    2014-03-01

    Full Text Available The paper describes experimental equipment for measurement of static characteristics of rotary hydraulic motor. It is possible to measure flow, pressure, temperature, speed and torque by means of this equipment. It deals with measurement of static characteristics of a gear rotary hydraulic motor. Mineral oil is used as hydraulic liquid in this case. Flow, torque and speed characteristics are evaluated from measured parameters. Measured mechanical-hydraulic, flow and total efficiencies of the rotary hydraulic motor are adduced in the paper. It is possible to diagnose technical conditions of the hydraulic motor (eventually to recommend its exchange from the experimental measurements.

  3. Promoting water hydraulics in Malaysia: A green educational approach

    Science.gov (United States)

    Yusof, Ahmad Anas; Zaili, Zarin Syukri; Hassan, Siti Nor Habibah; Tuan, Tee Boon; Saadun, Mohd Noor Asril; Ibrahim, Mohd Qadafie

    2014-10-01

    In promoting water hydraulics in Malaysia, this paper presents research development of water hydraulics educational training system for secondary and tertiary levels in Malaysia. Water hydraulics trainer with robotic attachment has been studied in order to promote the usefulness of such educational tools in promoting sustainability and green technology in the country. The trainer is being developed in order to allow constructive curriculum development and continuous marketing research for the effectiveness and usefulness of using water in hydraulic power trainer. The research on water-based hydraulic trainer is now possible with the current development in water hydraulics technology.

  4. Hydraulic characterization of hydrothermally altered Nopal tuff

    Energy Technology Data Exchange (ETDEWEB)

    Green, R.T.; Meyer-James, K.A. [Southwest Research Institute, San Antonio, TX (United States); Rice, G. [George Rice and Associates, San Antonio, TX (United States)

    1995-07-01

    Understanding the mechanics of variably saturated flow in fractured-porous media is of fundamental importance to evaluating the isolation performance of the proposed high-level radioactive waste repository for the Yucca Mountain site. Developing that understanding must be founded on the analysis and interpretation of laboratory and field data. This report presents an analysis of the unsaturated hydraulic properties of tuff cores from the Pena Blanca natural analog site in Mexico. The basic intent of the analysis was to examine possible trends and relationships between the hydraulic properties and the degree of hydrothermal alteration exhibited by the tuff samples. These data were used in flow simulations to evaluate the significance of a particular conceptual (composite) model and of distinct hydraulic properties on the rate and nature of water flow.

  5. Simulation of a Hydraulic Pump Control Valve

    Science.gov (United States)

    Molen, G. Vander; Akers, A.

    1987-01-01

    This paper describes the mode of operation of a control valve assembly that is used with a hydraulic pump. The operating system of the valve is modelled in a simplified form, and an analogy for hydraulic resonance of the pressure sensing system is presented. For the control valve investigated, air entrainment, length and diameter of the resonator neck, and valve mass produced the greatest shift in resonant frequency. Experimental work was conducted on the hydraulic system so that the resonance levels and frequencies could be measured and the accuracy of the theory verified. The results obtained make it possible to evaluate what changes to any of the variables considered would be most effective in driving the second harmonic frequency above the operating range.

  6. Soil Structure and Saturated Hydraulic Conductivity

    Science.gov (United States)

    Houskova, B.; Nagy, V.

    The role of soil structure on saturated hydraulic conductivity changes is studied in plough layers of texturally different soils. Three localities in western part of Slovakia in Zitny ostrov (Corn Island) were under investigation: locality Kalinkovo with light Calcaric Fluvisol (FAO 1970), Macov with medium heavy Calcari-mollic Fluvisol and Jurova with heavy Calcari-mollic Fluvisol. Soil structure was determined in dry as well as wet state and in size of macro and micro aggregates. Saturated hydraulic conductivity was measured by the help of double ring method. During the period of ring filling the soil surface was protected against aggregates damage by falling water drops. Spatial and temporal variability of studied parameters was evaluated. Cultivated crops were ensilage maize at medium heavy and heavy soil and colza at light soil. Textural composition of soil and actual water content at the beginning of measurement are one of major factor affecting aggregate stability and consequently also saturated hydraulic conductivity.

  7. Universal asymptotic umbrella for hydraulic fracture modeling

    CERN Document Server

    Linkov, Aleksandr M

    2014-01-01

    The paper presents universal asymptotic solution needed for efficient modeling of hydraulic fractures. We show that when neglecting the lag, there is universal asymptotic equation for the near-front opening. It appears that apart from the mechanical properties of fluid and rock, the asymptotic opening depends merely on the local speed of fracture propagation. This implies that, on one hand, the global problem is ill-posed, when trying to solve it as a boundary value problem under a fixed position of the front. On the other hand, when properly used, the universal asymptotics drastically facilitates solving hydraulic fracture problems (both analytically and numerically). We derive simple universal asymptotics and comment on their employment for efficient numerical simulation of hydraulic fractures, in particular, by well-established Level Set and Fast Marching Methods.

  8. Jet Quenching with Parton evolution

    CERN Document Server

    Cheng, Luan

    2009-01-01

    We report the evolution effects on jet energy loss with detailed balance. The initial conditions and parton evolution based on perturbative QCD in the chemical non-equilibrated medium and Bjorken expanding medium at RHIC are determined. The parton evolution affect the jet energy loss evidently. This will increase the energy and propagating distance dependence of the parton energy loss and will affect the shape of suppression of moderately high P_{T} hadron spectra.

  9. Jet-quenching and correlations

    Indian Academy of Sciences (India)

    Fuqiang Wang

    2015-05-01

    This article reviews recent advances in our understanding of the experimental aspects of jet-quenching and correlations in relativistic heavy-ion collisions at RHIC and LHC. Emphasis is put on correlation measurements, namely jet-like correlations with anisotropic flow subtraction in heavy-ion collisions and long-range pseudorapidity correlations in small systems. Future path on correlation studies is envisioned which may elucidate jet–medium interactions and the properties of the hot dense medium in QCD.

  10. Self-potential observations during hydraulic fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Jeffrey R.; Glaser, Steven D.

    2007-09-13

    The self-potential (SP) response during hydraulic fracturing of intact Sierra granite was investigated in the laboratory. Excellent correlation of pressure drop and SP suggests that the SP response is created primarily by electrokinetic coupling. For low pressures, the variation of SP with pressure drop is linear, indicating a constant coupling coefficient (Cc) of -200 mV/MPa. However for pressure drops >2 MPa, the magnitude of the Cc increases by 80% in an exponential trend. This increasing Cc is related to increasing permeability at high pore pressures caused by dilatancy of micro-cracks, and is explained by a decrease in the hydraulic tortuosity. Resistivity measurements reveal a decrease of 2% prior to hydraulic fracturing and a decrease of {approx}35% after fracturing. An asymmetric spatial SP response created by injectate diffusion into dilatant zones is observed prior to hydraulic fracturing, and in most cases this SP variation revealed the impending crack geometry seconds before failure. At rupture, injectate rushes into the new fracture area where the zeta potential is different than in the rock porosity, and an anomalous SP spike is observed. After fracturing, the spatial SP distribution reveals the direction of fracture propagation. Finally, during tensile cracking in a point load device with no water flow, a SP spike is observed that is caused by contact electrification. However, the time constant of this event is much less than that for transients observed during hydraulic fracturing, suggesting that SP created solely from material fracture does not contribute to the SP response during hydraulic fracturing.

  11. Measurement and modeling of unsaturated hydraulic conductivity

    Science.gov (United States)

    Perkins, Kim S.; Elango, Lakshmanan

    2011-01-01

    The unsaturated zone plays an extremely important hydrologic role that influences water quality and quantity, ecosystem function and health, the connection between atmospheric and terrestrial processes, nutrient cycling, soil development, and natural hazards such as flooding and landslides. Unsaturated hydraulic conductivity is one of the main properties considered to govern flow; however it is very difficult to measure accurately. Knowledge of the highly nonlinear relationship between unsaturated hydraulic conductivity (K) and volumetric water content is required for widely-used models of water flow and solute transport processes in the unsaturated zone. Measurement of unsaturated hydraulic conductivity of sediments is costly and time consuming, therefore use of models that estimate this property from more easily measured bulk-physical properties is common. In hydrologic studies, calculations based on property-transfer models informed by hydraulic property databases are often used in lieu of measured data from the site of interest. Reliance on database-informed predicted values with the use of neural networks has become increasingly common. Hydraulic properties predicted using databases may be adequate in some applications, but not others. This chapter will discuss, by way of examples, various techniques used to measure and model hydraulic conductivity as a function of water content, K. The parameters that describe the K curve obtained by different methods are used directly in Richards’ equation-based numerical models, which have some degree of sensitivity to those parameters. This chapter will explore the complications of using laboratory measured or estimated properties for field scale investigations to shed light on how adequately the processes are represented. Additionally, some more recent concepts for representing unsaturated-zone flow processes will be discussed.

  12. On the Hydraulics of Flowing Horizontal Wells

    Science.gov (United States)

    Bian, A.; Zhan, H.

    2003-12-01

    A flowing horizontal well is a special type of horizontal well that does not have pumping/injecting facility. The discharge rate of a flowing horizontal well is controlled by the hydraulic gradient between the aquifer and the well and it generally varies with time if the hydraulic head of the aquifer is transient. This type of well has been used in landslide control, mining dewatering, water table control, underground water transportation through a horizontal tunnel, agricultural water drainage, and other applications. Flowing horizontal wells have quite different hydrodynamic characteristics from horizontal wells with fixed pumping or injecting rates because their discharge rates are functions of the aquifer hydraulic heads (Zhan et al, 2001; Zhan and Zlotnik, 2002). Hydraulics of flowing horizontal wells have rarely been studied although the hydraulics of flowing vertical wells have been extensively investigated before. The purpose of this paper is to obtain analytical solutions of groundwater flow to a flowing horizontal-well in a confined aquifer, in a water table aquifer without precipitation, and in a water table aquifer with precipitation. The functions of the flowing horizontal well discharge rates versus time will be obtained under above mentioned different aquifer conditions. The relationships of the aquifer hydraulic heads versus the discharge rates of the well will be investigated. The rate of water table decline due to the dewatering of the well will also be computed, and this solution is particularly useful for landslide control and mining dewatering. The theoretical solutions will be compared with results of experiments that will be conducted in the hydrological laboratory at Texas A&M University. Reference: Zhan, H., Wang, L.V., and Park, E, On the horizontal well pumping tests in the anisotropic confined aquifers, J. hydrol., 252, 37-50, 2001. Zhan, H., and Zlotnik, V. A., Groundwater flow to a horizontal or slanted well in an unconfined aquifer

  13. Jets and environment of microquasars

    CERN Document Server

    Zhang, Shuang-Nan

    2008-01-01

    Two relativistic X-ray jets have been detected with the Chandra X-ray observatory from the black hole X-ray transient XTE J1550-564. We report a full analysis of the evolution of the two jets with a gamma-ray burst external shock model. A plausible scenario suggests a cavity outside the central source and the jets first travelled with constant velocity and then are slowed down by the interactions between the jets and the interstellar medium (ISM). The best fitted radius of the cavity is $\\sim$0.36 pc on the eastern side and $\\sim$0.46 pc on the western side, and the densities also show asymmetry, of $\\sim$0.015 cm$^{-3}$ on the east to $\\sim$0.21 cm$^{-3}$ on the west. A large scale low density region is also found in another microquasar system, H 1743-322. These results are consistent with previous suggestions that the environment of microquasars should be rather vacuous, compared to the normal Galactic environment. A generic scenario for microquasar jets is proposed, classifying the observed jets into three...

  14. Numerical Simulations of Bouncing Jets

    CERN Document Server

    Bonito, Andrea; Lee, Sanghyun

    2015-01-01

    Bouncing jets are fascinating phenomenons occurring under certain conditions when a jet impinges on a free surface. This effect is observed when the fluid is Newtonian and the jet falls in a bath undergoing a solid motion. It occurs also for non-Newtonian fluids when the jets falls in a vessel at rest containing the same fluid. We investigate numerically the impact of the experimental setting and the rheological properties of the fluid on the onset of the bouncing phenomenon. Our investigations show that the occurrence of a thin lubricating layer of air separating the jet and the rest of the liquid is a key factor for the bouncing of the jet to happen. The numerical technique that is used consists of a projection method for the Navier-Stokes system coupled with a level set formulation for the representation of the interface. The space approximation is done with adaptive finite elements. Adaptive refinement is shown to be very important to capture the thin layer of air that is responsible for the bouncing.

  15. [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.

  16. 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.

  17. Thermal Hydraulic Stability in a Coaxial Thermosyphon

    Institute of Scientific and Technical Information of China (English)

    YANG Jianhui; LU Wenqiang; LI Qing; LI Qiang; ZHOU Yuan

    2005-01-01

    The heat transfer and thermal hydraulic stability in a two-phase thermosyphon with coaxial riser and down-comer has been experimentally investigated and theoretically analyzed to facilitate its application in cold neutron source. The flow in a coaxial thermosyphon was studied experimentally for a variety of heating rates, transfer tube lengths, charge capacities, and area ratios. A numerical analysis of the hydraulic balance between the driving pressure head and the resistance loss has also been performed. The results show that the presented coaxial thermosyphon has dynamic performance advantages relative to natural circulation in a boiling water reactor.

  18. Large-eddy simulation in hydraulics

    CERN Document Server

    Rodi, Wolfgang

    2013-01-01

    Complex turbulence phenomena are of great practical importance in hydraulics, including environmental flows, and require advanced methods for their successful computation. The Large Eddy Simulation (LES), in which the larger-scale turbulent motion is directly resolved and only the small-scale motion is modelled, is particularly suited for complex situations with dominant large-scale structures and unsteadiness. Due to the increasing computer power, LES is generally used more and more in Computational Fluid Dynamics. Also in hydraulics, it offers great potential, especially for near-field probl

  19. Mineral resource of the month: hydraulic cement

    Science.gov (United States)

    van Oss, Hendrik G.

    2012-01-01

    Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

  20. Relativistic AGN jets I. The delicate interplay between jet structure, cocoon morphology and jet-head propagation

    CERN Document Server

    Walg, S; Markoff, S; Keppens, R; Meliani, Z

    2013-01-01

    Current observations have shown that astrophysical jets reveal strong signs of radial structure. They suggest that the inner region of the jet, the jet spine, consists of a low-density, fast-moving gas, while the outer region of the jet consists of a more dense and slower moving gas, called the jet sheath. Moreover, if jets carry angular momentum, the resultant centrifugal forces lead to a radial stratification. Current observations are not able to fully resolve the radial structure, so little is known about its actual profile. We present three AGN jet models in $2.5D$ of which two have been given a radial structure. The first model is a homogeneous jet, the only model that doesn't carry angular momentum; the second model is a spine-sheath jet with an isothermal equation of state; and the third jet model is a (piecewise) isochoric spine-sheath jet, with constant but different densities for jet spine and jet sheath. In this paper, we look at the effects of radial stratification on jet integrity, mixing between...

  1. From free jets to clinging wall jets: The influence of a horizontal boundary on a horizontally forced buoyant jet

    Science.gov (United States)

    Burridge, H. C.; Hunt, G. R.

    2017-02-01

    We investigate the incompressible turbulent jet formed when buoyant fluid is steadily ejected horizontally from a circular source into an otherwise quiescent uniform environment. As our primary focus, we introduce a horizontal boundary beneath the source. For sufficiently small separations, the jet attaches and clings to the boundary, herein the "clinging jet," before, farther downstream, the jet is pulled away from the boundary by the buoyancy force. For larger source-boundary separations, the buoyant jet is free to rise under the action of the buoyancy force, herein the "free jet." Based on measurements of saline jets in freshwater surroundings we deduce the conditions required for a jet to cling. We present a data set that spans a broad range of source conditions for the variation in volume flux (indicative of entrainment), jet perimeter, and jet centerline for both "clinging" and "free" jets. For source Froude numbers Fr0≥12 the data collapse when scaled, displaying universal behaviors for both clinging and free jets. Our results for the variation in the volume flux across horizontal planes, π Qjet , show that within a few jet lengths of the source, π Qjet for the clinging jet exceeds that of a free jet with identical source conditions. However, when examined in a coordinate following the jet centerline π Qjet for free jets is greater. Finally, we propose a new parametrization for an existing integral model which agrees well with our experimental data as well as with data from other studies. Our findings offer the potential to tailor the dilution of horizontal buoyant jets by altering the distance at which they are released from a boundary.

  2. Quark and gluon jet properties in symmetric three-jet events

    CERN Document Server

    Buskulic, Damir; De Bonis, I; Décamp, D; Ghez, P; Goy, C; Lees, J P; Lucotte, A; Minard, M N; Odier, P; Pietrzyk, B; Chmeissani, M; Crespo, J M; Efthymiopoulos, I; Fernández, E; Fernández-Bosman, M; Garrido, L; Juste, A; Martínez, M; Orteu, S; Pacheco, A; Padilla, C; Palla, Fabrizio; Pascual, A; Perlas, J A; Riu, I; Sánchez, F; Teubert, F; Colaleo, A; Creanza, D; De Palma, M; Farilla, A; Gelao, G; Girone, M; Iaselli, Giuseppe; Maggi, G; Maggi, M; Marinelli, N; Natali, S; Nuzzo, S; Ranieri, A; Raso, G; Romano, F; Ruggieri, F; Selvaggi, G; Silvestris, L; Tempesta, P; Zito, G; Huang, X; Lin, J; Ouyang, Q; Wang, T; Xie, Y; Xu, R; Xue, S; Zhang, J; Zhang, L; Zhao, W; Alemany, R; Bazarko, A O; Bonvicini, G; Cattaneo, M; Comas, P; Coyle, P; Drevermann, H; Forty, Roger W; Frank, M; Hagelberg, R; Harvey, J; Jacobsen, R; Janot, P; Jost, B; Kneringer, E; Knobloch, J; Lehraus, Ivan; Martin, E B; Mato, P; Minten, Adolf G; Miquel, R; Mir, L M; Moneta, L; Oest, T; Palazzi, P; Pater, J R; Pusztaszeri, J F; Ranjard, F; Rensing, P E; Rolandi, Luigi; Schlatter, W D; Schmelling, M; Schneider, O; Tejessy, W; Tomalin, I R; Venturi, A; Wachsmuth, H W; Wildish, T; Witzeling, W; Wotschack, J; Ajaltouni, Ziad J; Barrès, A; Boyer, C; Falvard, A; Gay, P; Guicheney, C; Henrard, P; Jousset, J; Michel, B; Monteil, S; Montret, J C; Pallin, D; Perret, P; Podlyski, F; Proriol, J; Rossignol, J M; Fearnley, Tom; Hansen, J B; Hansen, J D; Hansen, J R; Hansen, P H; Nilsson, B S; Wäänänen, A; Kyriakis, A; Markou, C; Simopoulou, Errietta; Siotis, I; Vayaki, Anna; Zachariadou, K; Blondel, A; Bonneaud, G R; Brient, J C; Bourdon, P; Rougé, A; Rumpf, M; Tanaka, R; Valassi, Andrea; Verderi, M; Videau, H L; Candlin, D J; Parsons, M I; Focardi, E; Parrini, G; Corden, M; Delfino, M C; Georgiopoulos, C H; Jaffe, D E; Antonelli, A; Bencivenni, G; Bologna, G; Bossi, F; Campana, P; Capon, G; Chiarella, V; Felici, G; Laurelli, P; Mannocchi, G; Murtas, F; Murtas, G P; Passalacqua, L; Pepé-Altarelli, M; Curtis, L; Dorris, S J; Halley, A W; Knowles, I G; Lynch, J G; O'Shea, V; Raine, C; Reeves, P; Scarr, J M; Smith, K; Thompson, A S; Thomson, F; Thorn, S; Turnbull, R M; Becker, U; Braun, O; Geweniger, C; Graefe, G; Hanke, P; Hepp, V; Kluge, E E; Putzer, A; Rensch, B; Schmidt, M; Sommer, J; Stenzel, H; Tittel, K; Werner, S; Wunsch, M; Abbaneo, D; Beuselinck, R; Binnie, David M; Cameron, W; Colling, D J; Dornan, Peter J; Moutoussi, A; Nash, J; San Martin, G; Sedgbeer, J K; Stacey, A M; Dissertori, G; Girtler, P; Kuhn, D; Rudolph, G; Bowdery, C K; Brodbeck, T J; Colrain, P; Crawford, G; Finch, A J; Foster, F; Hughes, G; Sloan, Terence; Whelan, E P; Williams, M I; Galla, A; Greene, A M; Kleinknecht, K; Quast, G; Renk, B; Rohne, E; Sander, H G; Van Gemmeren, P; Zeitnitz, C; Aubert, Jean-Jacques; Bencheikh, A M; Benchouk, C; Bonissent, A; Bujosa, G; Calvet, D; Carr, J; Diaconu, C A; Etienne, F; Konstantinidis, N P; Nicod, D; Payre, P; Rousseau, D; Talby, M; Sadouki, A; Thulasidas, M; Trabelsi, K; Abt, I; Assmann, R W; Bauer, C; Blum, Walter; Brown, D; Dietl, H; Dydak, Friedrich; Ganis, G; Gotzhein, C; Jakobs, K; Kroha, H; Lütjens, G; Lutz, Gerhard; Männer, W; Moser, H G; Richter, R H; Rosado-Schlosser, A; Schael, S; Settles, Ronald; Seywerd, H C J; Saint-Denis, R; Wiedenmann, W; Wolf, G; Boucrot, J; Callot, O; Cordier, A; Davier, M; Duflot, L; Grivaz, J F; Heusse, P; Jacquet, M; Kim, D W; Le Diberder, F R; Lefrançois, J; Lutz, A M; Nikolic, I A; Park, H J; Park, I C; Schune, M H; Simion, S; Veillet, J J; Videau, I; Azzurri, P; Bagliesi, G; Batignani, G; Bettarini, S; Bozzi, C; Calderini, G; Carpinelli, M; Ciocci, M A; Ciulli, V; Dell'Orso, R; Fantechi, R; Ferrante, I; Foà, L; Forti, F; Giassi, A; Giorgi, M A; Gregorio, A; Ligabue, F; Lusiani, A; Marrocchesi, P S; Messineo, A; Rizzo, G; Sanguinetti, G; Sciabà, A; Spagnolo, P; Steinberger, Jack; Tenchini, Roberto; Tonelli, G; Vannini, C; Verdini, P G; Walsh, J; Betteridge, A P; Blair, G A; Bryant, L M; Cerutti, F; Chambers, J T; Gao, Y; Green, M G; Johnson, D L; Medcalf, T; Perrodo, P; Strong, J A; Von Wimmersperg-Töller, J H; Botterill, David R; Clifft, R W; Edgecock, T R; Haywood, S; Edwards, M; Maley, P; Norton, P R; Thompson, J C; Bloch-Devaux, B; Colas, P; Emery, S; Kozanecki, Witold; Lançon, E; Lemaire, M C; Locci, E; Marx, B; Pérez, P; Rander, J; Renardy, J F; Roussarie, A; Schuller, J P; Schwindling, J; Trabelsi, A; Vallage, B; Johnson, R P; Kim, H Y; Litke, A M; McNeil, M A; Taylor, G; Beddall, A; Booth, C N; Boswell, R; Brew, C A J; Cartwright, S L; Combley, F; Köksal, A; Letho, M; Newton, W M; Rankin, C; Reeve, J; Thompson, L F; Böhrer, A; Brandt, S; Cowan, G D; Feigl, E; Grupen, Claus; Lutters, G; Minguet-Rodríguez, J A; Rivera, F; Saraiva, P; Smolik, L; Stephan, F; Apollonio, M; Bosisio, L; Della Marina, R; Giannini, G; Gobbo, B; Musolino, G; Ragusa, F; Rothberg, J E; Wasserbaech, S R; Armstrong, S R; Bellantoni, L; Elmer, P; Feng, Z; Ferguson, D P S; Gao, Y S; González, S; Grahl, J; Greening, T C; Harton, J L; Hayes, O J; Hu, H; McNamara, P A; Nachtman, J M; Orejudos, W; Pan, Y B; Saadi, Y; Schmitt, M; Scott, I J; Sharma, V; Turk, J; Walsh, A M; Wu Sau Lan; Wu, X; Yamartino, J M; Zheng, M; Zobernig, G

    1996-01-01

    Quark and gluon jets with the same energy, 24GeV, are compared in symmetric three-jet configurations from hadronic Z decays observed by the ALEPH detector. Jets are defined using the Durham algorithm. Gluon jets are identified using an anti-tag on b jets, based on either a track impact parameter method or a high transverse momentum lepton tag. The comparison of gluon and mixed flavour quark jets shows that gluon jets have a softer fragmentation function, a larger angular width and a higher particle multiplicity. Evidence is also presented which shows that the corresponding differences between gluon and heavy flavour jets are significantly smaller.

  3. Jets from ultraluminous X-ray sources

    Science.gov (United States)

    Urquhart, Ryan

    2017-08-01

    An important set of unsolved problems in accretion physics is whether super-Eddington accretion flows produce jets, what the jet power is (compared with the accretion power), and what the large-scale effect of the jet is on the surrounding gas. Most ultraluminous X-ray sources (ULXs) are super-Eddington stellar-mass compact objects: they provide the best local-Universe test of MHD accretion flow simulations. Observational evidence of collimated jets and fast outflows in ULXs may come in different forms: steady synchrotron radio emission from an unresolved, persistent core; radio flaring associated with discrete ejecta; internal shocks along the jet; hotspots from the jet/ISM interaction; hundred-parsec scale wind/jet-inflated nebulae. We discuss examples of the various cases, use them as proxies to measure the jet power, and compare them with (sub-Eddington) AGN and X-ray binary jets.

  4. Airframe-Jet Engine Integration Noise

    Science.gov (United States)

    Tam, Christopher; Antcliff, Richard R. (Technical Monitor)

    2003-01-01

    It has been found experimentally that the noise radiated by a jet mounted under the wing of an aircraft exceeds that of the same jet in a stand-alone environment. The increase in noise is referred to as jet engine airframe integration noise. The objectives of the present investigation are, (1) To obtain a better understanding of the physical mechanisms responsible for jet engine airframe integration noise or installation noise. (2) To develop a prediction model for jet engine airframe integration noise. It is known that jet mixing noise consists of two principal components. They are the noise from the large turbulence structures of the jet flow and the noise from the fine scale turbulence. In this investigation, only the effect of jet engine airframe interaction on the fine scale turbulence noise of a jet is studied. The fine scale turbulence noise is the dominant noise component in the sideline direction. Thus we limit out consideration primarily to the sideline.

  5. Exotic interactions among C-jets and Pb-jets

    Science.gov (United States)

    1985-01-01

    The C-jets and Pb-jets were surveyed on the part of Chacaltaya emulsion chamber No.19 amounting to an exposure of 28.8 sq m yr. It is shown that the adopted events make up an unbiased sample of C-jets for sigma sub E gamma TeV. Mini-Centauro interaction gives the most natural explanation for the eight pinaught-less C-jets with three or more constituent shower core. Out of the eight double-cored pinaught-less events, three are found to have visible invariant masses 1.8 GeV/c. Three Pb-jets-lower are composed of double cores whose respective visible transverse momenta are greater than 0.5 GeV/c, suggesting that they are of Geminion origin or chiron origin. The energies of the parent particles are estimated to be 100 to 200 TeV for all three kinds of events. The implications of this energy estimate and the frequency of observed exotic events are discussed.

  6. Mechatronic Hydraulic Drive with Regulator, Based on Artificial Neural Network

    Science.gov (United States)

    Burennikov, Y.; Kozlov, L.; Pyliavets, V.; Piontkevych, O.

    2017-06-01

    Mechatronic hydraulic drives, based on variable pump, proportional hydraulics and controllers find wide application in technological machines and testing equipment. Mechatronic hydraulic drives provide necessary parameters of actuating elements motion with the possibility of their correction in case of external loads change. This enables to improve the quality of working operations, increase the capacity of machines. The scheme of mechatronic hydraulic drive, based on the pump, hydraulic cylinder, proportional valve with electrohydraulic control and programmable controller is suggested. Algorithm for the control of mechatronic hydraulic drive to provide necessary pressure change law in hydraulic cylinder is developed. For the realization of control algorithm in the controller artificial neural networks are used. Mathematical model of mechatronic hydraulic drive, enabling to create the training base for adjustment of artificial neural networks of the regulator is developed.

  7. DCS Hydraulics Submittal, Valencia County, New Mexico, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  8. Chapter 12. Pure Tap Water Hydraulic Systems and Applications

    DEFF Research Database (Denmark)

    Conrad, Finn; Adelstorp, Anders

    1997-01-01

    Presentation of developed a modern pure tap water hydraulic components (Nessie), systems and industrial applications.......Presentation of developed a modern pure tap water hydraulic components (Nessie), systems and industrial applications....

  9. A tensor approach to the estimation of hydraulic conductivities in ...

    African Journals Online (AJOL)

    2006-07-03

    Jul 3, 2006 ... The HC values computed from the data measured on the weathered or ... Keywords: hydraulic conductivity tensor, roughness, combined stress, hydraulic aperture, Table Mountain ... the anisotropic nature of studied media.

  10. The use of asphalt in hydraulic engineering

    NARCIS (Netherlands)

    Van de Velde, P.A.; Ebbens, E.H.; Van Herpen, J.A.

    1985-01-01

    Asphalt products have been used in the Netherlands in hydraulic engineering for a long time on a large scale, especially after the great disaster in 1953 when a large part of western Holland was flooded by the sea. After the disaster a great number of dikes had to be repaired very quickly and this w

  11. Elevator and hydraulics; Elevator to yuatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, I. [Hitachi, Ltd., Tokyo (Japan)

    1994-07-15

    A hydraulic type elevator is installed in relatively lower buildings as compared with a rope type elevator, but the ratio in the number of installation of the former elevator is increasing. This paper explains from its construction and features to especially various control systems for the riding comfort and safety. A direct push-up system with hydraulic jacks arranged beneath a car, and an indirect push-up system that has hydraulic jacks arranged on flank of a car and transmits the movement of a plunger via a rope are available. The latter system eliminates the need of large holes to embed hydraulic jacks. While the speed is controlled by controlling flow rates of high-pressure oil, the speed, position, acceleration and even time differential calculus of the acceleration must be controlled severely. The system uses two-step control for the through-speed and the landing speed. Different systems that have been realized may include compensation for temperatures in flow rate control valves, load pressures, and oil viscosity, from learning control to fuzzy control for psychological effects, or control of inverters in motors. 13 refs., 12 figs., 1 tab.

  12. Hydraulic adjustment of Scots pine across Europe

    NARCIS (Netherlands)

    Martínez-Vilalta, J.; Cochard, H.; Mencuccini, M.; Sterck, F.J.; Herrero, A.; Korhonen, J.F.J.; Llorens, P.; Nikinmaa, E.; Nolè, A.; Poyatos, R.; Ripullone, F.; Sass-Klaassen, U.; Zweifel, R.

    2009-01-01

    The variability of branch-level hydraulic properties was assessed across 12 Scots pine populations covering a wide range of environmental conditions, including some of the southernmost populations of the species. The aims were to relate this variability to differences in climate, and to study the po

  13. Influence of tray hydraulics on tray column

    NARCIS (Netherlands)

    Betlem, Bernardus H.L.; Rijnsdorp, J.E.; Rijnsdorp, J.E.; Azink, R.F.

    1998-01-01

    To column control, in contrast to column design, tray hold-up and dependencies of tray hold-up on the operating conditions play an important role. The essence of this article is the development of an improved model of tray hydraulics over a broad operating range and its experimental validation by

  14. Design of a hydraulic bending machine

    Science.gov (United States)

    Steven G. Hankel; Marshall Begel

    2004-01-01

    To keep pace with customer demands while phasing out old and unserviceable test equipment, the staff of the Engineering Mechanics Laboratory (EML) at the USDA Forest Service, Forest Products Laboratory, designed and assembled a hydraulic bending test machine. The EML built this machine to test dimension lumber, nominal 2 in. thick and up to 12 in. deep, at spans up to...

  15. Sustainable hydraulic engineering through building with nature

    NARCIS (Netherlands)

    Vriend, de H.J.; Koningsveld, van M.; Aarninkhof, S.G.J.; Vries, de M.B.; Baptist, M.J.

    2015-01-01

    Hydraulic engineering infrastructures are of concern to many people and are likely to interfere with the environment. Moreover, they are supposed to keep on functioning for many years. In times of rapid societal and environmental change this implies that sustainability and adaptability are important

  16. The use of asphalt in hydraulic engineering

    NARCIS (Netherlands)

    Van de Velde, P.A.; Ebbens, E.H.; Van Herpen, J.A.

    1985-01-01

    Asphalt products have been used in the Netherlands in hydraulic engineering for a long time on a large scale, especially after the great disaster in 1953 when a large part of western Holland was flooded by the sea. After the disaster a great number of dikes had to be repaired very quickly and this w

  17. International Institute for Hydraulic and Environmental Engineering

    Science.gov (United States)

    Mostertman, L. J.

    1977-01-01

    Describes the activities of the International Institute for Hydraulic and Environmental Engineering (IHE), whose primary function is the promotion of the better use of water resources as a vehicle of development by the transfer of knowledge and experience. (Author/RK)

  18. Digital hydraulic valving system. [design and development

    Science.gov (United States)

    1973-01-01

    The design and development are reported of a digital hydraulic valving system that would accept direct digital inputs. Topics include: summary of contractual accomplishments, design and function description, valve parameters and calculations, conclusions, and recommendations. The electrical control circuit operating procedure is outlined in an appendix.

  19. Sustainable hydraulic engineering through building with nature

    NARCIS (Netherlands)

    Vriend, de H.J.; Koningsveld, van M.; Aarninkhof, S.G.J.; Vries, de M.B.; Baptist, M.J.

    2015-01-01

    Hydraulic engineering infrastructures are of concern to many people and are likely to interfere with the environment. Moreover, they are supposed to keep on functioning for many years. In times of rapid societal and environmental change this implies that sustainability and adaptability are important

  20. Reactive barriers: hydraulic performance and design enhancements.

    Science.gov (United States)

    Painter, B D M

    2004-01-01

    The remediation of contaminated ground water is a multibillion-dollar global industry. Permeable reactive barriers (PRBs) are one of the leading technologies being developed in the search for alternatives to the pump-and-treat method. Improving the hydraulic performance of these PRBs is an important part of maximizing their potential to the industry. Optimization of the hydraulic performance of a PRB can be defined in terms of finding the balance between capture, residence time, and PRB longevity that produces a minimum-cost acceptable design. Three-dimensional particle tracking was used to estimate capture zone and residence time distributions. Volumetric flow analysis was used for estimation of flow distribution across a PRB and in the identification of flow regimes that may affect the permeability or reactivity of portions of the PRB over time. Capture zone measurements extended below the base of partially penetrating PRBs and were measured upgradient from the portion of aquifer influenced by PRB emplacement. Hydraulic performance analysis of standard PRB designs confirmed previously presented research that identified the potential for significant variation in residence time and capture zone. These variations can result in the need to oversize the PRB to ensure that downgradient contaminant concentrations do not exceed imposed standards. The most useful PRB design enhancements for controlling residence time and capture variation were found to be customized downgradient gate faces, velocity equalization walls, deeper emplacement of the funnel than the gate, and careful manipulation of the hydraulic conductivity ratio between the gate and the aquifer.

  1. SITMILARITY LAW FOR HYDRAULIC DISTORTED MODEL

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Newton's general similarity criterion was applied to the distorted model. The results for the similarities of gravity force, drag force and pressure force are identical with those derived from relevant differential equations of fluid flow. And the selected limits of the distorted ratio were studied and the simulation of roughness coefficient of distorted model was conducted by means of hydraulic test.

  2. Separation and pattern formation in hydraulic jumps

    DEFF Research Database (Denmark)

    Bohr, Tomas; Ellegaard, C.; Hansen, A. Espe;

    1998-01-01

    We present theory and experiments on the circular hydraulic jump in the stationary regime. The theory can handle the situation in which the fluid flows over an edge far away from the jump. In the experiments the external height is controlled, and a series of transitions in the flow structure appe...

  3. HYDRAULIC CONDUCTIVITY OF THREE GEOSYNTHETIC CLAY LINERS

    Science.gov (United States)

    The hydraulic conductivity of three 2.9 m2 (32 sq ft) geosynthetic clay liners (GCLs) was measured. Tests were performed on individual sheets of the GCLs, on overlapped pieces of GCLs, and on composite liners consisting of a punctured geomembrane overlying a GCL. Hyd...

  4. Towards Autonomous Control of Hydraulic Actuator Systems

    DEFF Research Database (Denmark)

    Hansen, Poul Erik; Conrad, Finn

    1998-01-01

    Presentation of new developed control algorithms to increase autonomy and intelligence of hydraulic control systems. A refinement of relaytuning method is used to determine the control parameters of a lag/lead controller and a poleplacement controller. Further, a fail-safe function is developed t...

  5. Power management in hydraulically actuated mobile equipment

    DEFF Research Database (Denmark)

    Pedersen, Henrik Clemmensen; Andersen, Torben Ole; Hansen, Michael Rygaard

    2008-01-01

    The focus of the current paper is on the control of hydraulic systems when utilizing the advances that electronic control may bring with regard to power management, prioritized flow sharing and anti-stall, arising from being able to control both pump, valves and engine electronically. A simple mo...

  6. Dentin permeability: determinants of hydraulic conductance.

    Science.gov (United States)

    Reeder, O W; Walton, R E; Livingston, M J; Pashley, D H

    1978-02-01

    A technique is described which permits measurements of the ease with which fluid permeates dentin. This value, the hydraulic conductance of dentin, increased as surface area increases and/or as dentin thickness decreases. It increased 32-fold when dentin was acid etched due to removal of surface debris occluding the tubules.

  7. Analysis of Innovative Design of Energy Efficient Hydraulic Actuators

    OpenAIRE

    M Osman Abdalla

    2013-01-01

    Hydraulic cylinder actuators are used extensively in industrial, construction and agricultural works. The small sized outlet ports of the cylinders resist the flow of discharged oil; and as a result the piston motion is slowed down. This causes a lot of heat generation and energy loss within the actuators. The study investigates and analyzes the possibilities of reducing the hydraulic resistance and increasing efficiency of the hydraulic actuator. Conventional hydraulic cylinders are simulate...

  8. DISCONTINUOUS FLOW OF TURBID DENSITY CURRENTS Ⅱ. INTERNAL HYDRAULIC JUMP

    Institute of Scientific and Technical Information of China (English)

    Jiahua FAN

    2005-01-01

    Traveling and stationary internal hydraulic jumps in density currents with positive or negative entrainment coefficients were analyzed based on simple assumptions. An expression of internal hydraulic jumps with entrainment coefficients was derived. Experimental data, published in literature, of stationary internal hydraulic jumps in turbid, thermal and saline density currents including measured values of water entrainment were used to compare with theory. Comparison was also made of traveling internal hydraulic jumps between measured data and theory.

  9. Jets from Jets: Re-clustering as a tool for large radius jet reconstruction and grooming at the LHC

    CERN Document Server

    Nachman, Benjamin; Schwartzman, Ariel; Swiatlowski, Maximilian

    2014-01-01

    Jets with a large radius $R\\gtrsim 1$ and grooming algorithms are widely used to fully capture the decay products of boosted heavy particles at the Large Hadron Collider (LHC). Unlike most discriminating variables used in such studies, the jet radius is usually not optimized for specific physics scenarios. This is because every jet configuration must be calibrated, insitu, to account for detector response and other experimental effects. One solution to enhance the availability of large-R jet configurations used by the LHC experiments is {\\it jet re-clustering}. Jet re-clustering introduces an intermediate scale $rjets are calibrated and used as the inputs to reconstruct large radius jets. In this paper we systematically study and propose new jet re-clustering configurations and show that re-clustered large radius jets have essentially the same jet mass performance as large radius groomed jets. Jet re-clustering has the benefit that no additional large-R calibration is necessary, allowing the r...

  10. OPTIMAL HYDRAULIC DESIGN AND CAD APPLICATIONS OF AXIAL FLOW HYDRAULIC TURBINE'S RUNNER

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A method of the optimal hydraulic design and CAD application of runner blades of axial-flow hydraulic turbines are discussed on the basis of optimization principle and CAD technique in this paper. Based on the theory of fluid dynamics, the blade′s main geometrical parameter, working parameters and performances index of the blades and the relationship between them are analysed, and the mathematical model of optimal hydraulic design of axial-flow runners has been established. Through nonlinear programming, the problems can be solved. By making use of the calculation geometry and computer graphics, the distribution method of the singular points, and an CAD applied software, an optimal hydraulic design are presented.

  11. Hydraulic Bureaucracy in a Modern Hydraulic Society – Strategic Group Formation in the Mekong Delta, Vietnam

    Directory of Open Access Journals (Sweden)

    Hans-Dieter Evers

    2009-10-01

    Among these strategic groups, the hydraulic bureaucracy and hydraulic construction business are the most crucial in terms of the specific role they play in the hydraulic landscape of the Mekong delta. Both groups exert considerable influence on water resources management and strive for the same resources, namely public funds (including Overseas Development Aid that is directed to hydraulic infrastructure development. This paper illustrates how both groups have emerged due to the growing need for water resources management in the delta and how they have set up alliances for mutually sharing resources in the long run. Furthermore, it is shown how both groups have adapted their resource-oriented strategies and actions to respond to the changes in the economic and political environment in Vietnam’s recent history.

  12. Hydraulic power take-off for wave energy systems

    DEFF Research Database (Denmark)

    Christensen, Georg Kronborg

    2001-01-01

    Investigation and laboratory experiments with a hydraulic power conversion system for converting forces from a 2.5m diamter float to extract energy from seawaves. The test rig consists of a hydraulic wave simulator and a hydraulic point absorber. The absorber converts the incomming forces...

  13. 21 CFR 880.5110 - Hydraulic adjustable hospital bed.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydraulic adjustable hospital bed. 880.5110... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Therapeutic Devices § 880.5110 Hydraulic adjustable hospital bed. (a) Identification. A hydraulic adjustable...

  14. 14 CFR 33.72 - Hydraulic actuating systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic actuating systems. 33.72 Section... AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.72 Hydraulic actuating systems. Each hydraulic actuating system must function properly under all conditions in which...

  15. 7 CFR 2902.10 - Mobile equipment hydraulic fluids.

    Science.gov (United States)

    2010-01-01

    ... Comprehensive Procurement Guideline, 40 CFR 247.11. ... 7 Agriculture 15 2010-01-01 2010-01-01 false Mobile equipment hydraulic fluids. 2902.10 Section... PROCUREMENT Designated Items § 2902.10 Mobile equipment hydraulic fluids. (a) Definition. Hydraulic...

  16. Comparison of four methods to assess hydraulic conductivity

    Energy Technology Data Exchange (ETDEWEB)

    Benson, C.H. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Civil and Environmental Engineering; Gunter, J.A. [Gunter (John A.), Round Rock, TX (United States); Boutwell, G.P. [STE, Inc., Baton Rouge, LA (United States); Trautwein, S.J. [Trautwein Soil Testing Equipment Co., Houston, TX (United States); Berzanskis, P.H. [Hoechst-Celanese, Inc., Pampa, TX (United States)

    1997-10-01

    A hydraulic conductivity assessment that was conducted on four test pads constructed to the same specifications with soil from the same source by four different contractors is described. The test pads had distinctly different field hydraulic conductivities, even though they were constructed with similar soil, to similar compaction conditions, and with similar machinery. Adequate hydration time was key in achieving low field hydraulic conductivity. More extensive processing was another factor responsible for low field hydraulic conductivity. Four different test methods were used to assess the hydraulic conductivity of each test pad: (1) sealed double-ring infiltrometers (SDRIs); (2) two-stage borehole permeameters; (3) laboratory hydraulic conductivity tests on large block specimens; and (4) laboratory hydraulic conductivity tests on small specimens collected in thin-wall sampling tubes. The tests were conducted independently by each of the writers. After the tests were completed, the results were submitted and compared. Analysis of the test results show that the three large-scale test methods generally yield similar hydraulic conductivities. For two of the test pads, however, the hydraulic conductivities of the specimens collected in sampling tubes were significantly lower than the field hydraulic conductivities. Both of these test pads had high field hydraulic conductivity. Thus, there is little value in using small specimens to assess field hydraulic conductivity.

  17. 23 CFR 650.111 - Location hydraulic studies.

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Location hydraulic studies. 650.111 Section 650.111 Highways FEDERAL HIGHWAY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS BRIDGES, STRUCTURES, AND HYDRAULICS Location and Hydraulic Design of Encroachments on Flood Plains §...

  18. Microscopic Processes in Relativistic Jets

    Science.gov (United States)

    Nishikawa, K.-I.; Hardee, P.; Mizuno, Y.; Medvedev, M.; Zhang, B.; Nordlund, A.; Fredricksen, J.; Sol, H.; Niemiec, J.; Lyubarsky, Y.; hide

    2008-01-01

    Nonthermal radiation observed from astrophysical systems containing relativistic jets and shocks, e.g., gamma-ray bursts (GRBs), active galactic nuclei (AGNs), and Galactic microquasar systems usually have power-law emission spectra. Recent PIC simulations of relativistic electron-ion (electro-positron) jets injected into a stationary medium show that particle acceleration occurs within the downstream jet. In the collisionless relativistic shock particle acceleration is due to plasma waves and their associated instabilities (e.g., the Buneman instability, other two-streaming instability, and the Weibel (filamentation) instability) created in the shocks are responsible for particle (electron, positron, and ion) acceleration. The simulation results show that the Weibel instability is responsible for generating and amplifying highly nonuniform, small-scale magnetic fields. These magnetic fields contribute to the electron's transverse deflection behind the jet head. The 'jitter' radiation from deflected electrons has different properties than synchrotron radiation which is calculated in a uniform magnetic field. This jitter radiation may be important to understanding the complex time evolution and/or spectral structure in gamma-ray bursts, relativistic jets, and supernova remnants.

  19. MHD Jets in inhomogeneous media

    Directory of Open Access Journals (Sweden)

    S. O´Sullivan

    2002-01-01

    Full Text Available Presentamos simulaciones de la propagaci on de jets moleculares no-adiab aticos en un medio ambiente inhomog eneo. Los jets tienen condiciones descritos por un modelo de jet MHD en el cual la forma de las l neas magn eticas se prescribe cerca de la fuente. Per les de densidad ambiental fueron elegidos para representar la zona de transici on entre las regiones exteriores de una nube molecular y el medio interestelar. Escalamos las tasas de enfriamiento at omico y molecular a niveles apropriados para resolver todas las escalas espaciales apropriadas. Con la inclusi on de variabilidad de la fuente, las simulaciones reproducen varias caracter sticas observacionales de jets moleculares, entre ellas las cavidades moleculares. Adicionalmente, encontramos similitudes entre teor a y observaci on para la fracci on de ionizaci on a lo largo del jet. Encontramos que la extensi on lateral de las super cies de trabajo internas son sensibles al medio ambiente. Tambi en presentamos resultados preliminares para un m etodo de calcular mapas de emisi on en l neas usando solamente variables fundamentales de estado que parecen reproducir la emisi on lamentosa de Balmer en frentes de choque.

  20. Supersonic induction plasma jet modeling

    Energy Technology Data Exchange (ETDEWEB)

    Selezneva, S.E. E-mail: svetlana2@hermes.usherbS_Selezneva2@hermes.usherb; Boulos, M.I

    2001-06-01

    Numerical simulations have been applied to study the argon plasma flow downstream of the induction plasma torch. It is shown that by means of the convergent-divergent nozzle adjustment and chamber pressure reduction, a supersonic plasma jet can be obtained. We investigate the supersonic and a more traditional subsonic plasma jets impinging onto a normal substrate. Comparing to the subsonic jet, the supersonic one is narrower and much faster. Near-substrate velocity and temperature boundary layers are thinner, so the heat flux near the stagnation point is higher in the supersonic jet. The supersonic plasma jet is characterized by the electron overpopulation and the domination of the recombination over the dissociation, resulting into the heating of the electron gas. Because of these processes, the supersonic induction plasma permits to separate spatially different functions (dissociation and ionization, transport and deposition) and to optimize each of them. The considered configuration can be advantageous in some industrial applications, such as plasma-assisted chemical vapor deposition of diamond and polymer-like films and in plasma spraying of nanoscaled powders.

  1. Nanofluid impingement jet heat transfer.

    Science.gov (United States)

    Zeitoun, Obida; Ali, Mohamed

    2012-02-17

    Experimental investigation to study the heat transfer between a vertical round alumina-water nanofluid jet and a horizontal circular round surface is carried out. Different jet flow rates, jet nozzle diameters, various circular disk diameters and three nanoparticles concentrations (0, 6.6 and 10%, respectively) are used. The experimental results indicate that using nanofluid as a heat transfer carrier can enhance the heat transfer process. For the same Reynolds number, the experimental data show an increase in the Nusselt numbers as the nanoparticle concentration increases. Size of heating disk diameters shows reverse effect on heat transfer. It is also found that presenting the data in terms of Reynolds number at impingement jet diameter can take into account on both effects of jet heights and nozzle diameter. Presenting the data in terms of Peclet numbers, at fixed impingement nozzle diameter, makes the data less sensitive to the percentage change of the nanoparticle concentrations. Finally, general heat transfer correlation is obtained verses Peclet numbers using nanoparticle concentrations and the nozzle diameter ratio as parameters.

  2. 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.

  3. Jet flow and premixed jet flame control by plasma swirler

    Science.gov (United States)

    Li, Gang; Jiang, Xi; Zhao, Yujun; Liu, Cunxi; Chen, Qi; Xu, Gang; Liu, Fuqiang

    2017-04-01

    A swirler based on dielectric barrier discharge plasma actuators is designed and its effectiveness in both jet flow and premixed jet flame control is demonstrated. In contrast to traditional spanwise-oriented actuators, plasma actuators are placed along the axial direction of the injector to induce a circumferential velocity to the main flow and create a swirl flow without any insertion or moving part. In the DBD plasma swirl injector, the discharge does not ignite the mixture nor does it induce flashback. Flame visualization is obtained by cameras while velocity profiles are obtained by Laser Doppler Anemometry measurements. The results obtained indicate the effectiveness of the new design.

  4. The first calculation of fractional jets

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Daniele [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Center for Theoretical Physics, University of California, Berkeley, CA 94720 (United States); Thaler, Jesse [Center for Theoretical Physics, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Walsh, Jonathan R. [Ernest Orlando Lawrence Berkeley National Laboratory, University of California, Berkeley, CA 94720 (United States); Center for Theoretical Physics, University of California, Berkeley, CA 94720 (United States)

    2015-05-04

    In collider physics, jet algorithms are a ubiquitous tool for clustering particles into discrete jet objects. Event shapes offer an alternative way to characterize jets, and one can define a jet multiplicity event shape, which can take on fractional values, using the framework of “jets without jets”. In this paper, we perform the first analytic studies of fractional jet multiplicity N-tilde{sub jet} in the context of e{sup +}e{sup −} collisions. We use fixed-order QCD to understand the N-tilde{sub jet} cross section at order α{sub s}{sup 2}, and we introduce a candidate factorization theorem to capture certain higher-order effects. The resulting distributions have a hybrid jet algorithm/event shape behavior which agrees with parton shower Monte Carlo generators. The N-tilde{sub jet} observable does not satisfy ordinary soft-collinear factorization, and the N-tilde{sub jet} cross section exhibits a number of unique features, including the absence of collinear logarithms and the presence of soft logarithms that are purely non-global. Additionally, we find novel divergences connected to the energy sharing between emissions, which are reminiscent of rapidity divergences encountered in other applications. Given these interesting properties of fractional jet multiplicity, we advocate for future measurements and calculations of N-tilde{sub jet} at hadron colliders like the LHC.

  5. Two Jet Production at CDF

    Energy Technology Data Exchange (ETDEWEB)

    Dell' Agnello, Simone; /INFN, Pisa

    1989-01-01

    CDF (Collider Detector at Fermilab) is a full-coverage magnetic detector studying p{bar p} collisions at the {radical}s = 1.8 TeV Tevatron Collider. The experiment has collected a handful of demonstration events towards the end 1985, and had its first significant run in spring 1987. Most of this run was operated with a 'buffet trigger', one stream of which was an inclusive large-E{sub t} trigger. Large E{sub t} (E{sub t} >50 GeV) events at the Tevatron show an increasingly dominant component with two or more hard jets. This thesis consists in an analysis of these jet events. The invariant cross-secton as a function of jet pair mass (M{sub jj}) is derived.

  6. Dye Aggregation in Ink Jet

    Institute of Scientific and Technical Information of China (English)

    Thomas Paul; Sarfraz Hussain

    2004-01-01

    Dye aggregation has long been recognised as a key factor in performance, and this is no less so in ink jet applications. The aggregation state was shown to be important in many different areas ranging from the use of dyes in photodynamic therapies all the way to colorants for dying of fabrics. Therefore different methods to investigate dye association qualitatively and quantitatively were developed. A simple procedure to study aggregation could be a useful tool to characterise dyes for ink jet printing. It is critically reviewed the methods used to study dye aggregation, and discussed some of the main conclusions. This will be illustrated by examples of ink jet dye aggregation and its study in aqueous and ink systems. The results are used to correlate the solution behaviour of dyes with their print performance.

  7. Advanced thermally stable jet fuels

    Energy Technology Data Exchange (ETDEWEB)

    Schobert, H.H.

    1999-01-31

    The Pennsylvania State University program in advanced thermally stable coal-based jet fuels has five broad objectives: (1) Development of mechanisms of degradation and solids formation; (2) Quantitative measurement of growth of sub-micrometer and micrometer-sized particles suspended in fuels during thermal stressing; (3) Characterization of carbonaceous deposits by various instrumental and microscopic methods; (4) Elucidation of the role of additives in retarding the formation of carbonaceous solids; (5) Assessment of the potential of production of high yields of cycloalkanes by direct liquefaction of coal. Future high-Mach aircraft will place severe thermal demands on jet fuels, requiring the development of novel, hybrid fuel mixtures capable of withstanding temperatures in the range of 400--500 C. In the new aircraft, jet fuel will serve as both an energy source and a heat sink for cooling the airframe, engine, and system components. The ultimate development of such advanced fuels requires a thorough understanding of the thermal decomposition behavior of jet fuels under supercritical conditions. Considering that jet fuels consist of hundreds of compounds, this task must begin with a study of the thermal degradation behavior of select model compounds under supercritical conditions. The research performed by The Pennsylvania State University was focused on five major tasks that reflect the objectives stated above: Task 1: Investigation of the Quantitative Degradation of Fuels; Task 2: Investigation of Incipient Deposition; Task 3: Characterization of Solid Gums, Sediments, and Carbonaceous Deposits; Task 4: Coal-Based Fuel Stabilization Studies; and Task 5: Exploratory Studies on the Direct Conversion of Coal to High Quality Jet Fuels. The major findings of each of these tasks are presented in this executive summary. A description of the sub-tasks performed under each of these tasks and the findings of those studies are provided in the remainder of this volume

  8. Assimilation of temperature and hydraulic gradients for quantifying the spatial variability of streambed hydraulics

    Science.gov (United States)

    Huang, Xiang; Andrews, Charles B.; Liu, Jie; Yao, Yingying; Liu, Chuankun; Tyler, Scott W.; Selker, John S.; Zheng, Chunmiao

    2016-08-01

    Understanding the spatial and temporal characteristics of water flux into or out of shallow aquifers is imperative for water resources management and eco-environmental conservation. In this study, the spatial variability in the vertical specific fluxes and hydraulic conductivities in a streambed were evaluated by integrating distributed temperature sensing (DTS) data and vertical hydraulic gradients into an ensemble Kalman filter (EnKF) and smoother (EnKS) and an empirical thermal-mixing model. The formulation of the EnKF/EnKS assimilation scheme is based on a discretized 1D advection-conduction equation of heat transfer in the streambed. We first systematically tested a synthetic case and performed quantitative and statistical analyses to evaluate the performance of the assimilation schemes. Then a real-world case was evaluated to calculate assimilated specific flux. An initial estimate of the spatial distributions of the vertical hydraulic gradients was obtained from an empirical thermal-mixing model under steady-state conditions using a constant vertical hydraulic conductivity. Then, this initial estimate was updated by repeatedly dividing the assimilated specific flux by estimates of the vertical hydraulic gradients to obtain a refined spatial distribution of vertical hydraulic gradients and vertical hydraulic conductivities. Our results indicate that optimal parameters can be derived with fewer iterations but greater simulation effort using the EnKS compared with the EnKF. For the field application in a stream segment of the Heihe River Basin in northwest China, the average vertical hydraulic conductivities in the streambed varied over three orders of magnitude (5 × 10-1 to 5 × 102 m/d). The specific fluxes ranged from near zero (qz < ±0.05 m/d) to ±1.0 m/d, while the vertical hydraulic gradients were within the range of -0.2 to 0.15 m/m. The highest and most variable fluxes occurred adjacent to a debris-dam and bridge pier. This phenomenon is very likely

  9. Hydraulics and pneumatics a technician's and engineer's guide

    CERN Document Server

    Parr, Andrew

    1991-01-01

    Hydraulics and Pneumatics: A Technician's and Engineer's Guide provides an introduction to the components and operation of a hydraulic or pneumatic system. This book discusses the main advantages and disadvantages of pneumatic or hydraulic systems.Organized into eight chapters, this book begins with an overview of industrial prime movers. This text then examines the three different types of positive displacement pump used in hydraulic systems, namely, gear pumps, vane pumps, and piston pumps. Other chapters consider the pressure in a hydraulic system, which can be quickly and easily controlled

  10. 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.

  11. QCD and jets at hadron colliders

    Science.gov (United States)

    Sapeta, Sebastian

    2016-07-01

    We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in particular for cases in which jets are produced in special configurations, like for example in the region of forward rapidities. We review numerous perturbative methods for calculating predictions for jet processes, including the fixed-order calculations as well as various matching and merging techniques. We also discuss the questions related to non-perturbative effects and the role they play in precision jet studies. We describe the status of calculations for processes with jet vetoes and we also elaborate on production of jets in forward direction. Throughout the article, we present selected comparisons between state-of-the-art theoretical predictions and the data from the LHC.

  12. QCD and Jets at Hadron Colliders

    CERN Document Server

    Sapeta, Sebastian

    2016-01-01

    We review various aspects of jet physics in the context of hadron colliders. We start by discussing the definitions and properties of jets and recent development in this area. We then consider the question of factorization for processes with jets, in particular for cases in which jets are produced in special configurations, like for example in the region of forward rapidities. We review numerous perturbative methods for calculating predictions for jet processes, including the fixed-order calculations as well as various matching and merging techniques. We also discuss the questions related to non-perturbative effects and the role they play in precision jet studies. We describe the status of calculations for processes with jet vetoes and we also elaborate on production of jets in forward direction. Throughout the article, we present selected comparisons between state-of-the-art theoretical predictions and the data from the LHC.

  13. Magnetohydrodynamic Origin of Jets from Accretion Disks

    CERN Document Server

    Lovelace, R V E; Koldoba, A V

    1999-01-01

    A review is made of recent magnetohydrodynamic (MHD) theory and simulations of origin of jets from accretion disks. Many compact astrophysical objects emit powerful, highly-collimated, oppositely directed jets. Included are the extra galactic radio jets of active galaxies and quasars, and old compact stars in binaries, and emission line jets in young stellar objects. It is widely thought that these different jets arise from rotating, conducting accretion disks threaded by an ordered magnetic field. The twisting of the magnetic field by the rotation of the disk drives the jets by magnetically extracting matter, angular momentum, and energy from the accretion disk. Two main regimes have been discussed theoretically, hydromagnetic winds which have a significant mass flux, and Poynting flux jets where the mass flux is negligible. Over the past several years, exciting new developments on models of jets have come from progress in MHD simulations which now allow the study of the origin - the acceleration and collima...

  14. Quark vs Gluon Jet Tagging at ATLAS

    CERN Document Server

    Rubbo, Francesco; The ATLAS collaboration

    2017-01-01

    Distinguishing quark-initiated from gluon-initiated jets is useful for many measurements and searches at the LHC. We present a quark-initiated versus gluon-initiated jet tagger from the ATLAS experiment using the number of reconstructed charged particles inside the jet. The measurement of the charged-particle multiplicity inside jets from Run 1 is used to derive uncertainties on the tagger performance for Run 2. With an efficiency of 60% to select quark-initiated jets, the efficiency to select gluon-initiated jets is between 10 and 20% across a wide range in jet pT up to 1.5 TeV with about an absolute 5% systematic uncertainty on the efficiencies. In addition, we also present preliminary studies on a tagger for the ATLAS experiment using the full radiation pattern inside a jet processed as images in deep neural network classifiers.

  15. Nonlinear Dynamics of Coiling in Viscoelastic Jets

    CERN Document Server

    Majmudar, Trushant; Hartt, William; McKinley, Gareth

    2010-01-01

    Instabilities in free surface continuous jets of non-Newtonian fluids, although relevant for many industrial processes, remain less well understood in terms of fundamental fluid dynamics. Inviscid, and viscous Newtonian jets have been studied in great detail; buckling instability in viscous jets leads to regular periodic coiling of the jet that exhibits a non-trivial frequency dependence with the height of the fall. Very few experimental or theoretical studies exist for continuous viscoelastic jets beyond the onset of the first instability. Here, we present a systematic study of the effects of viscoelasticity on the dynamics of free surface continuous jets of surfactant solutions that form worm-like micelles. We observe complex nonlinear spatio-temporal dynamics of the jet and uncover a transition from periodic to doubly-periodic or quasi-periodic to a multi-frequency, possibly chaotic dynamics. Beyond this regime, the jet dynamics smoothly crosses over to exhibit the "leaping shampoo effect" or the Kaye effe...

  16. HF Transverse Segmentation and Tagging Jet Capability

    CERN Document Server

    Doroshkevich, E A; Kuleshov, Sergey

    1998-01-01

    So called tagging jets and pile-up were simulated for the optimisation of the HF segmentation. The energy resolution, angular resolution and efficiency of jet reconstruction are defined for different calorimeter segmentation.

  17. ATLAS jet trigger performance in 2015 data

    CERN Document Server

    Herwig, Theodor Christian; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. The hadronic jet trigger is used to select several different topologies containing different types and multiplicities of hadronic jets, thus supporting many different physics searches and measurements. The hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13 TeV is presented. The efficient selection of events containing hadronic jets requires the characteristics of trigger-level jets and offline jets to be very similar. A comparison of relevant characteristics demonstrates that trigger-level jets and offline jets are in excellent agreement.

  18. ATLAS jet trigger performance in 2016 data

    CERN Document Server

    Herwig, Theodor Christian; The ATLAS collaboration

    2016-01-01

    The ATLAS experiment at the LHC uses a two-level trigger system to preferentially select events with a predefined topology of interest for future analysis. The hadronic jet trigger is used to select several different topologies containing different types and multiplicities of hadronic jets, thus supporting many different physics searches and measurements. The hadronic jet trigger efficiency for proton-proton collision data at a centre-of-mass energy of 13 TeV is presented. The efficient selection of events containing hadronic jets requires the characteristics of trigger-level jets and offline jets to be very similar. A comparison of relevant characteristics demonstrates that trigger-level jets and offline jets are in excellent agreement.

  19. Jets in deep inelastic electroproduction

    CERN Document Server

    Drews, G; Erickson, R; Gebert, W; Janata, F; Joos, P; Ladage, A; Messing, F; Nagel, H; Nordberg, E; Preissner, H; Sadoff, A; Siemann, R; Smith-Kintner, J; Söding, P; Stein, P

    1979-01-01

    Results on jet structure of the hadronic final state in electron- proton scattering are presented. The kinematic range includes 1jet axis determined with sphericity or thrust and the direction of the virtual photon is measured. Comparison with data from e/sup +/e /sup -/ annihilation is made. A method to estimate the intrinsic transverse momentum of the quark in the target proton is presented. (8 refs).

  20. Stagnation knots in precessing Jets

    Directory of Open Access Journals (Sweden)

    Andrew J. Lim

    2002-01-01

    Full Text Available Se investiga el problema de la formaci on de nudos de estancamiento en la cabeza de un jet estelar en precesi on desde los puntos de vista anal tico y num erico. Esta estructura de alta densidad se forma v a un m etodo similar al que propuso Ste en (estas memorias para la formaci on de FLIERs en nebulosas planetarias. Resultados iniciales sugieren que la formaci on de un nudo de estancamiento posiblemente sea una inestabilidad intr nseca de jets en precesi on.

  1. V+jets from CMS

    CERN Document Server

    Hortiangtham, Apichart

    2016-01-01

    The production of vector bosons (V = W, Z or $\\gamma$) in association with jets is a stringent test of perturbative QCD and is a background process in searches for new physics. Total and differential cross-section measurements of vector bosons produced in association with jets (and heavy flavour quarks) are presented. The data have been recorded with the CMS detector at the LHC and are compared to next-to leading order calculations and event simulations that devise matrix element calculations interfaced with parton showers.

  2. Study of Several Impinging Jets

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Impinging Jets are frequently adapted for cooling overheated parts.With the film cooling technique,this process improves thermal exchanges between walls and fluid.However if many works have concerned only the thermal aspect of this problem[1],its dynamic field has been rarely studied especially for multiple impingements.As the two phenomena caanot be totally dissociated.we have undertaken the aerodynamic and thermal study of jets impinging on a aplane wall,Various techniques,have been used as visualizations(spreading over method.LASER sheet visualizations),LDA measurements to propose a topology schema of the flow and infraed thermography.

  3. Physical factors of primary jet vectoring control using synthetic jet actuators

    Institute of Scientific and Technical Information of China (English)

    XIA Zhi-xun; LUO Zhen-bing

    2007-01-01

    A primary jet vectoring using synthetic jet actuators with different exit configurations was investigated, and the main physical factors influencing jet vectoring were analyzed and summarized. The physical factors of the pressure difference, the location and area of the lower pressure region, the component of the synthetic jet momentum and the entrainment ratio of the synthetic jet flow to primary jet flow directly control the vectoring force and the vectoring angle. Three characteristic parameters of the synthetic jet contribute to the pressure difference and the area of the lower pressure region Both the extension step and slope angle of the actuator exit have functions of regulating the location of the lower pressure region, the area of the lower pressure region, and the entrainment ratio of the synthetic jet flow to primary jet flow. The slope angle of the actuator exit has additional functions of regulating the component of the synthetic jet momentum. Based upon analyzing the physical factors of jet vectoring control with synthetic jets, the source variables of the physical factors were established. A preparatory control model of jet vectoring using synthetic jet actuator was presented, and it has the benefit of explaining the efficiency of jet vectoring using synthetic jet actuator with source variables at different values, and it indicates the optimal actuator is taking full advantage of the regulating function.

  4. Multiple Jets at the LHC with High Energy Jets

    DEFF Research Database (Denmark)

    Andersen, Jeppe Rosenkrantz; Smillie, Jennifer M.

    2011-01-01

    -level accuracy for multiplicities up to 4 jets. The resummation includes all-order hard corrections, which become important for increasing centre-of-mass energy of the hadronic collision. We discuss observables relevant for confronting the perturbative framework with 7 TeV data from the LHC, and the impact...

  5. Inclusive jet production at the Tevatron

    Energy Technology Data Exchange (ETDEWEB)

    Norniella, Olga; /Barcelona, IFAE

    2006-08-01

    Preliminary results on inclusive jet production in proton-antiproton collisions at {radical}s = 1.96 TeV based on 1 fb{sup -1} of CDF Run II data are presented. Measurements are preformed using different jet algorithms in a wide range of jet transverse momentum and jet rapidity. The measured cross sections are compared to next-to-leading order perturbative QCD calculations

  6. Charm jet identification at the CMS experiment

    CERN Document Server

    Moortgat, Seth

    2016-01-01

    Identification of jets originating from c quarks becomes more and more important for a wide variety of standard model physics as well as searches for physics beyond the standard model. Recently, the CMS collaboration developed a charm-jet algorithm, trained to discriminate against b jets and light-quark or gluon jets. In this presentation, we will describe this newly developed algorithm and present its performance on the 13 TeV data.

  7. Academic Training Lecture: Jets at Hadron Colliders

    CERN Multimedia

    PH Department

    2011-01-01

    Regular Programme 30, 31 March and 1 April  2011 from 11:00 to 12:00 -  Bldg. 40-S2-A01 - Salle Andersson Jets at Hadron Colliders by Gavin Salam These three lectures will discuss how jets are defined at hadron colliders, the physics that is responsible for the internal structure of jets and the ways in which an understanding of jets may help in searches for new particles at the LHC.

  8. 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...

  9. The Georgi Algorithms of Jet Clustering

    OpenAIRE

    Ge, Shao-Feng

    2014-01-01

    We reveal the direct link between the jet clustering algorithms recently proposed by Howard Georgi and parton shower kinematics, providing firm foundation from the theoretical side. The kinematics of this class of elegant algorithms is explored systematically for partons with arbitrary masses and the jet function is generalized to $J^{(n)}_\\beta$ with a jet function index $n$ in order to achieve more degrees of freedom. Based on three basic requirements that, the result of jet clustering is p...

  10. A novel energy recovery system for parallel hybrid hydraulic excavator.

    Science.gov (United States)

    Li, Wei; Cao, Baoyu; Zhu, Zhencai; Chen, Guoan

    2014-01-01

    Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the proposed energy recovery system is calculated based on the mathematical models. Meanwhile, the simulation models of the proposed system and a conventional energy recovery system are built by AMESim software. The results show that the proposed system is more effective than the conventional energy saving system. At last, the main components of the proposed energy recovery system including accumulator and hydraulic motor are analyzed for improving the energy recovery efficiency. The measures to improve the energy recovery efficiency of the proposed system are presented.

  11. JetCurry: Modeling 3D geometry of AGN jets from 2D images

    Science.gov (United States)

    Kosak, Katie; Li, KunYang; Avachat, Sayali S.; Perlman, Eric S.

    2017-02-01

    Written in Python, JetCurry models the 3D geometry of jets from 2-D images. JetCurry requires NumPy and SciPy and incorporates emcee (ascl:1303.002) and AstroPy (ascl:1304.002), and optionally uses VPython. From a defined initial part of the jet that serves as a reference point, JetCurry finds the position of highest flux within a bin of data in the image matrix and fits along the x axis for the general location of the bends in the jet. A spline fitting is used to smooth out the resulted jet stream.

  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. Jet quenching and γ-jet correlation in high-energy heavy-ion collisions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-Nian [Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University, Wuhan 430079 (China); Nuclear Science Division Mailstop 70R0319, Lawrence Berkeley National Laboratory, Berkeley, CA 94740 (United States); Zhu, Yan [Departamento de Física de Partículas and IGFAE, Universidade de Santiago de Compostela, E-15706 Santiago de Compostela, Galicia (Spain)

    2014-12-15

    Medium modification of γ-tagged jets in high-energy heavy-ion collisions is investigated within a linearized Boltzmann transport model which includes both elastic parton scattering and induced gluon emission. In Pb + Pb collisions at √(s)=2.76 TeV, a γ-tagged jet is seen to lose 15% of its energy at 0–10% central collisions. Simulations also point to a sizable azimuthal angle broadening of γ-tagged jets at the tail of a distribution which should be measurable when experimental errors are significantly reduced. An enhancement at large z{sub jet}=p{sub L}/E{sub jet} in jet fragmentation function at the Large Hadron Collider (LHC) can be attributed to the dominance of leading particles in the reconstructed jet. A γ-tagged jet fragmentation function is shown to be more sensitive to jet quenching, therefore a better probe of the jet transport parameter.

  14. 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.

  15. Monte Carlo Tools for Jet Quenching

    OpenAIRE

    Zapp, Korinna

    2011-01-01

    A thorough understanding of jet quenching on the basis of multi-particle final states and jet observables requires new theoretical tools. This talk summarises the status and propects of the theoretical description of jet quenching in terms of Monte Carlo generators.

  16. Understanding jets at the Large Hadron Collider

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Matthew D. [Harvard Univ., Cambridge, MA (United States). Dept. of Physics

    2016-11-17

    Jet physics is an exciting and rapidly growing branch of particle physics, particularly relevant to the energy frontier. Just a few years ago, jets were universally treated as structureless objects, representing the momentum of an underlying quark or gluon. Nowadays, jets are understood to be intricate, dynamical objects with interesting hidden properties worthy of investigation and relevant for understanding quantum field theory.

  17. ECRH for JET: A feasibility study

    NARCIS (Netherlands)

    Lennholm, M.; Giruzzi, G.; Parkin, A.; Bouquey, F.; Braune, H.; Bruschi, A.; de la Luna, E.; Denisov, G.; Edlington, T.; Farina, D.; Farthing, J.; Figini, L.; Garavaglia, S.; Garcia, J.; Gerbaud, T.; Granucci, G.; Henderson, M.; Horton, L.; Kasparek, W.; Khilar, P.; Jennison, M.; Kirneva, N.; Kislov, D.; Kuyanov, A.; Litaudon, X.; Litvak, A. G.; Moro, A.; Nowak, S.; Parail, V.; Plaum, B.; Rimini, F.; Saibene, G.; Sips, A.; Sozzi, C.; Späh, P.; Trukhina, E.; Vaccaro, A.; Vdovin, V.

    2011-01-01

    For JET to fulfil its mission in preparing ITER operation, the installation of an electron cyclotron resonance heating system on JET would be desirable. The study described in this paper has investigated the feasibility of installing such a system on JET. The principal goals of such a system are: cu

  18. Technology of load-sensitivity used in the hydraulic system of an all-hydraulic core rig

    Institute of Scientific and Technical Information of China (English)

    XIN De-zhong; CHEN Song-ling; WANG Qing-feng

    2009-01-01

    The existing hydraulic system always have problems of temperature rise, run-ning stability and anti-interference of the implementation components, reliability of hydrau-lic components, maintenance difficulties, and other issues. With high efficiency, energy saving, reliability, easy operating, stable running, anti-interference ability, and other ad-vantages, the load-sensitive hydraulic system is more suitable for coal mine all-hydraulic core rig. Therefore, for the technical development of the coal mine all-hydraulic core rig, the load-sensitive technology employed by the rig should be of great significance.

  19. Trends in Design of Water Hydraulics

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents and discusses a R&D-view on trends in development and best practise in design of both low-pressure and high-pressure tap water hydraulic components and systems for motion control as well as open-ended solutions various industrial applications. The focus is on the advantages using...... ordinary tap water and the range of application areas are illustrated with examples, in particular within the food processing industry, humidification operations, water mist systems for fire fighting, high water pressure cleaners, water moisturising systems for wood processing, lumber drying process...... operate with pure water from the tap without additives of any kind. Hence water hydraulics takes the benefit of pure water as fluid being environmentally friendly, easy to clean sanitary design, non-toxic, non-flammable, inexpensive, readily available and easily disposable. The low-pressure tap water...

  20. The hydraulic fracturing of geothermal formations

    Energy Technology Data Exchange (ETDEWEB)

    Naceur, K. Ben; Economides, M.J.; Schlumberger, Dowell

    1988-01-01

    Hydraulic fracturing has been attempted in geothermal formations as a means to stimulate both production and injection wells. Since most geothermal formations contain fissures and on occasion massive natural fissures, the production behavior of the man-made fractures results in certain characteristic trends. A model is offered that allows the presence of a finite or infinite conductivity fracture intercepting a fissured medium. The method is based on a numerical discretization of the formation allowing transient interporosity flow. Type curves for pressure drawdown and cumulative production are given for infinite acting and closed reservoirs. Since most of the fissured formations exhibit a degree of anisotropy, the effects of the orientation of the hydraulic fracture with respect to the fissure planes, and of the ratio between the directional permeabilities are then discussed. Guidelines are offered as to the size of appropriate stimulation treatments based on the observed fissured behavior of the reservoir.