WorldWideScience

Sample records for burner flow controls

  1. PASSIVE CONTROL OF PARTICLE DISPERSION IN A PARTICLE-LADEN CIRCULAR JET USING ELLIPTIC CO-ANNULAR FLOW: A MEANS FOR IMPROVING UTILIZATION AND EMISSION REDUCTIONS IN PULVERIZED COAL BURNER

    Energy Technology Data Exchange (ETDEWEB)

    Ahsan R. Choudhuri

    2003-06-01

    A passive control technology utilizing elliptic co-flow to control the particle flinging and particle dispersion in a particle (coal)-laden flow was investigated using experimental and numerical techniques. Preferential concentration of particles occurs in particle-laden jets used in pulverized coal burner and causes uncontrollable NO{sub x} formation due to inhomogeneous local stoichiometry. This particular project was aimed at characterizing the near-field flow behavior of elliptic coaxial jets. The knowledge gained from the project will serve as the basis of further investigation on fluid-particle interactions in an asymmetric coaxial jet flow-field and thus is important to improve the design of pulverized coal burners where non-homogeneity of particle concentration causes increased NO{sub x} formation.

  2. Efficient industrial burner control of a flexible burner management system; Effiziente industrielle Brennertechnik durch Einsatz flexibler Feuerungsautomaten

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Ulrich; Saenger, Peter [Siemens AG, Rastatt (Germany)

    2012-02-15

    Compactness and flexibility of a burner control system is a very important issue. With a few types a wide range in different industrial applications should be covered. This paper presents different applications of a new burner control system: heating of cooling lines in glass industry, steam generation and air heating for a pistachio roastery and in grain dryers. (orig.)

  3. Effect of the mixing fields on the stability and structure of turbulent partially premixed flames in a concentric flow conical nozzle burner

    KAUST Repository

    Mansour, Mohy S.; Elbaz, Ayman M.; Roberts, William L.; Senosy, Mohamed S.; Zayed, Mohamed F.; Juddoo, Mrinal; Masri, Assaad R.

    2016-01-01

    of partially premixed methane flames. The mixing field in a concentric flow conical nozzle (CFCN) burner with well-controlled mechanism of the mixing is investigated using Rayleigh scattering technique. The flame stability, structure and flow field of some

  4. The flow field structure of highly stabilized partially premixed flames in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.; Zayed, M.F.; Samy, M.; Roberts, William L.; Mansour, Mohy S.

    2015-01-01

    The stability limits, the stabilization mechanism, and the flow field structure of highly stabilized partially premixed methane flames in a concentric flow conical nozzle burner with air co-flow have been investigated and presented in this work

  5. Measurements of non-reacting and reacting flow fields of a liquid swirl flame burner

    Science.gov (United States)

    Chong, Cheng Tung; Hochgreb, Simone

    2015-03-01

    The understanding of the liquid fuel spray and flow field characteristics inside a combustor is crucial for designing a fuel efficient and low emission device. Characterisation of the flow field of a model gas turbine liquid swirl burner is performed by using a 2-D particle imaging velocimetry(PIV) system. The flow field pattern of an axial flow burner with a fixed swirl intensity is compared under confined and unconfined conditions, i.e., with and without the combustor wall. The effect of temperature on the main swirling air flow is investigated under open and non-reacting conditions. The result shows that axial and radial velocities increase as a result of decreased flow density and increased flow volume. The flow field of the main swirling flow with liquid fuel spray injection is compared to non-spray swirling flow. Introduction of liquid fuel spray changes the swirl air flow field at the burner outlet, where the radial velocity components increase for both open and confined environment. Under reacting condition, the enclosure generates a corner recirculation zone that intensifies the strength of radial velocity. The reverse flow and corner recirculation zone assists in stabilizing the flame by preheating the reactants. The flow field data can be used as validation target for swirl combustion modelling.

  6. Numerical Simulation of Gas-Solid Two-Phase Flow for Four-Channels Pulverized Swirling Burner

    Directory of Open Access Journals (Sweden)

    Defu LI

    2013-05-01

    Full Text Available This article presents a mathematical model of cold gas-solid two-phase flow which is based on the cement rotary kiln in service. By altering the parameters of air supply system of four- channels pulverized burner, investigations are taken of that motion trajectory and particle distributions in the very turbulent field. The results show that motion trail of most particles in rotary kiln is a combination process of gradual diffusion and slow sedimentation; increasing internal flow velocity would aggravate coal particles to diffuse; external flow velocity should be controlled in a reasonable range.

  7. Highly stabilized partially premixed flames of propane in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.

    2018-01-11

    Partially premixed turbulent flames with non-homogeneous jet of propane were generated in a concentric flow conical nozzle burner in order to investigate the effect of the coflow on the stability and flame structure. The flame stability is first mapped and then high-speed stereoscopic particle image velocimetry, SPIV, plus OH planar laser-induced fluorescence, OH-PLIF, measurements were conducted on a subset of four flames. The jet equivalence ratio Φ = 2, Jet exit Reynolds number Re = 10,000, and degree of premixing are kept constant for the selected flames, while the coflow velocity, Uc, is progressively changed from 0 to 15 m/s. The results showed that the flame is stable between two extinction limits of mixture inhomogeneity, and the optimum stability is obtained at certain degree of mixture inhomogeneity. Increasing Φ, increases the span between these two extinction limits, while these limits converge to a single point (corresponding to optimum mixture inhomogeneity) with increasing Re. Regardless the value of Φ, increasing the coflow velocity improves the flame stability. The correlation between recessed distance of the burner tubes and the fluctuation of the mixture fraction, Δξ, shows that at Δξ around 40% of the flammability limits leads to optimum flame stability. The time averaged SPIV results show that the coflow induces a big annular recirculation zone surrounds the jet flames. The size and the location of this zone is seen to be sensitive to Uc. However, the instantaneous images show the existence of a small vortical structure close to the shear layer, where the flame resides there in the case of no-coflow. These small vertical structures are seen playing a vital role in the flame structure, and increasing the flame corrugation close to the nozzle exit. Increasing the coflow velocity expands the central jet at the expense of the jet velocity, and drags the flame in the early flame regions towards the recirculation zone, where the flame tracks

  8. Optimal Switching Control of Burner Setting for a Compact Marine Boiler Design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan M.

    2010-01-01

    This paper discusses optimal control strategies for switching between different burner modes in a novel compact  marine boiler design. The ideal behaviour is defined in a performance index the minimisation of which defines an ideal trade-off between deviations in boiler pressure and water level...... approach is based on a generalisation of hysteresis control. The strategies are verified on a simulation model of the compact marine boiler for control of low/high burner load switches.  ...

  9. Burner flow regulators with mechanisms performing two variable function. Meccanismi che generano una funzione di due variabili applicati alla regolazione dei bruciatori

    Energy Technology Data Exchange (ETDEWEB)

    Borelli, L.; Tagliaferro, B. (R.B.L. Riello Bruciatori, Legnago Spa, Legnago (Italy)); Cossalter, V.; Da Lio, M. (Padua Univ. (Italy). Dip. di Ingegneria Meccanica)

    1993-08-01

    A new class of fuel oil burners has recently been developed by an Italian firm with the aim of obtaining high performances in terms of both energy efficiency and air pollution abatement. The innovative feature of these burners is that they are equipped with a device which permits the automatic and optimum regulation of the air fuel mixture independent of ambient and operating conditions. To reduce costs, the regulation system is a mechanical one instead of electronic which would require an expensive lambda probe. The mechanical regulating system controls air intake by simply taking into account two main combustion factors - ambient temperature and the nominal fuel flow rate. The special cam mechanism is thus classified as one which performs a single function with two degrees of freedom, i.e., the independent variables of ambient temperature and nominal fuel flow. One of the air intake valve's movements is governed by a temperature transducer, the other (primary), by a screw which allows the registering of the air flow during burner installation or upon completion of periodic maintenance checks. In addition to optimizing combustion control, this control technique affords the possibility to adapt the air flow to the different fuel flows obtained by changing the type of nozzle or supply pressure.

  10. Large Eddy Simulation of Flow Structures in the Sydney Swirl Burner

    DEFF Research Database (Denmark)

    Yang, Yang

    . The theories of LES and the corresponding closure models have been well developed. This research focuses on statistical analysing flow field and characteristic features. Validation studies show good agreement in the isothermal cases, while for the reacting case, the LES predictions are less satisfactory...... zone which starts at the burner surface. As for the medium swirling isothermal case, there are two reverse flow zones in the reacting case. Due to the low stoichiometric mixture fraction in the methane flame, only the outer layer of the bluff‐body induced reverse zone is reactive. The main reactive...... method strategy has limitations concerning wall bounded flows, especially for complex geometries typically found in industry. Multi‐phase flows need special treatment....

  11. DESIGN AND DEVELOPMENT OF MILD COMBUSTION BURNER

    Directory of Open Access Journals (Sweden)

    M.M. Noor

    2013-12-01

    Full Text Available This paper discusses the design and development of the Moderate and Intense Low oxygen Dilution (MILD combustion burner using Computational Fluid Dynamics (CFD simulations. The CFD commercial package was used to simulate preliminary designs for the burner before the final design was sent to the workshop for fabrication. The burner is required to be a non-premixed and open burner. To capture and use the exhaust gas, the burner was enclosed within a large circular shaped wall with an opening at the top. An external EGR pipe was used to transport the exhaust gas which was mixed with the fresh oxidant. To control the EGR and exhaust flow, butterfly valves were installed at the top opening as a damper to close the exhaust gas flow at a certain ratio for EGR and exhaust out to the atmosphere. High temperature fused silica glass windows were installed to view and capture images of the flame and analyze the flame propagation. The burner simulation shows that MILD combustion was achieved for the oxygen mole fraction of 3-13%. The final design of the burner was fabricated and ready for the experimental validation.

  12. Large Eddy Simulation Analysis on Confined Swirling Flows in a Gas Turbine Swirl Burner

    Directory of Open Access Journals (Sweden)

    Tao Liu

    2017-12-01

    Full Text Available This paper describes a Large Eddy Simulation (LES investigation into flow fields in a model gas turbine combustor equipped with a swirl burner. A probability density function was used to describe the interaction physics of chemical reaction and turbulent flow as liquid fuel was directly injected into the combustion chamber and rapidly mixed with the swirling air. Simulation results showed that heat release during combustion accelerated the axial velocity motion and made the recirculation zone more compact. As the combustion was taking place under lean burn conditions, NO emissions was less than 10 ppm. Finally, the effects of outlet contraction on swirling flows and combustion instability were investigated. Results suggest that contracted outlet can enhance the generation of a Central Vortex Core (CVC flow structure. As peak RMS of velocity fluctuation profiles at center-line suggested the turbulent instability can be enhanced by CVC motion, the Power Spectrum Density (PSD amplitude also explained that the oscillation at CVC position was greater than other places. Both evidences demonstrated that outlet contraction can increase the instability of the central field.

  13. Investigation of pore-scale flow physics in porous media burners

    Science.gov (United States)

    Sobhani, Sadaf; Muhunthan, Priyanka; Boigne, Emeric; Mohaddes, Danyal; Ihme, Matthias; Stanford University Team

    2017-11-01

    Porous media burners (PMBs) operate on the principle that the solid porous matrix serves as a means of internally recirculating heat from the combustion products upstream to the reactants, enabling a reduction of the lean-flammability limit, higher power dynamic range, and lower NOx and CO emissions as compared to conventional systems. Accurate predictions of the flow features and properties such as pressure loss in reticulated ceramic foams is an important step in the characterization and optimization of combustion in porous media. In this work, an integrated framework is proposed from obtaining the porous sample to performing a computational fluid dynamics simulation, including X-ray microtomography scanning, digital topology rendering, and volume meshing. Three-dimensional numerical simulations of the flow in the complex geometries of porous foams are obtained by solution of the Navier-Stokes equations using an unstructured, finite-volume solver. This capability enables the investigation of pore-scale flow physics in a wide range of porous materials used in PMBs. In this talk, results obtained at pore-scale Reynolds numbers of order 10 to 100 in a Silicone Carbide foam are presented to demonstrate this capability.

  14. Hybrid model predictive control applied to switching control of burner load for a compact marine boiler design

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan

    2008-01-01

    This paper discusses the application of hybrid model predictive control to control switching between different burner modes in a novel compact marine boiler design. A further purpose of the present work is to point out problems with finite horizon model predictive control applied to systems for w...

  15. The flow field structure of highly stabilized partially premixed flames in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.

    2015-08-29

    The stability limits, the stabilization mechanism, and the flow field structure of highly stabilized partially premixed methane flames in a concentric flow conical nozzle burner with air co-flow have been investigated and presented in this work. The stability map of partial premixed flames illustrates that the flames are stable between two extinction limits. A low extinction limit when partial premixed flames approach non-premixed flame conditions, and a high extinction limit, with the partial premixed flames approach fully premixed flame conditions. These two limits showed that the most stable flame conditions are achieved at a certain degree of partial premixed. The stability is improved by adding air co-flow. As the air co-flow velocity increases the most stable flames are those that approach fully premixed. The turbulent flow field of three flames at 0, 5, 10 m/s co-flow velocity are investigated using Stereo Particle Image Velocimetry (SPIV) in order to explore the improvement of the flame stability due to the use of air co-flow. The three flames are all at a jet equivalence ratio (Φj) of 2, fixed level of partial premixing and jet Reynolds number (Rej) of 10,000. The use of co-flow results in the formation of two vortices at the cone exit. These vortices act like stabilization anchors for the flames to the nozzle tip. With these vortices in the flow field, the reaction zone shifts toward the reduced turbulence intensity at the nozzle rim of the cone. Interesting information about the structure of the flow field with and without co-flow are identified and reported in this work.

  16. COST-EFFECTIVE CONTROL OF NOx WITH INTEGRATED ULTRA LOW-NOx BURNERS AND SNCR

    International Nuclear Information System (INIS)

    Hamid Farzan

    2001-01-01

    Coal-fired electric utilities are facing a serious challenge with regards to curbing their NO(sub x) emissions. At issue are the NO(sub x) contributions to the acid rain, ground level ozone, and particulate matter formation. Substantial NO(sub x) control requirements could be imposed under the proposed Ozone Transport Rule, National Ambient Air Quality Standards, and New Source Performance Standards. McDermott Technology, Inc. (MTI), Babcock and Wilcox (B and W), and Fuel Tech are teaming to provide an integrated solution for NO(sub x) control. The system will be comprised of an ultra low-NO(sub x) pulverized coal (PC) burner technology plus a urea-based, selective non-catalytic reduction (SNCR) system. This system will be capable of meeting a target emission limit of 0.15 lb NO(sub x)/10(sup 6) Btu and target ammonia (NH3) slip level targeted below 5 ppmV for commercial units. Our approach combines the best available combustion and post-combustion NO(sub x) control technologies. More specifically, B and W's DRB-4Z TM ultra low-NO(sub x) PC burner technology will be combined with Fuel Tech's NO(sub x)OUT (SNCR) and NO(sub x)OUT Cascade (SNCR/SCR hybrid) systems and jointly evaluated and optimized in a state-of-the-art test facility at MTI. Although the NO(sub x)OUT Cascade (SNCR/SCR hybrid) system will not be tested directly in this program, its potential application for situations that require greater NO(sub x) reductions will be inferred from other measurements (i.e., SNCR NO(sub x) removal efficiency plus projected NO(sub x) reduction by the catalyst based on controlled ammonia slip). Our analysis shows that the integrated ultra low-NO(sub x) burner and SNCR system has the lowest cost when the burner emissions are 0.25 lb NO(sub x)/10(sup 6) Btu or less. At burner NO(sub x) emission level of 0.20 lb NO(sub x)/10(sup 6) Btu, the levelized cost per ton of NO(sub x) removed is 52% lower than the SCR cost

  17. Reduction of exposure to ultrafine particles by kitchen exhaust hoods: the effects of exhaust flow rates, particle size, and burner position.

    Science.gov (United States)

    Rim, Donghyun; Wallace, Lance; Nabinger, Steven; Persily, Andrew

    2012-08-15

    Cooking stoves, both gas and electric, are one of the strongest and most common sources of ultrafine particles (UFP) in homes. UFP have been shown to be associated with adverse health effects such as DNA damage and respiratory and cardiovascular diseases. This study investigates the effectiveness of kitchen exhaust hoods in reducing indoor levels of UFP emitted from a gas stove and oven. Measurements in an unoccupied manufactured house monitored size-resolved UFP (2 nm to 100 nm) concentrations from the gas stove and oven while varying range hood flow rate and burner position. The air change rate in the building was measured continuously based on the decay of a tracer gas (sulfur hexafluoride, SF(6)). The results show that range hood flow rate and burner position (front vs. rear) can have strong effects on the reduction of indoor levels of UFP released from the stove and oven, subsequently reducing occupant exposure to UFP. Higher range hood flow rates are generally more effective for UFP reduction, though the reduction varies with particle diameter. The influence of the range hood exhaust is larger for the back burner than for the front burner. The number-weighted particle reductions for range hood flow rates varying between 100 m(3)/h and 680 m(3)/h range from 31% to 94% for the front burner, from 54% to 98% for the back burner, and from 39% to 96% for the oven. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Cutting edge SRU control : improved environmental compliance with Jacobs advanced burner control+ (ABC+)

    Energy Technology Data Exchange (ETDEWEB)

    Molenaar, G. [Jacobs Canada Inc., Calgary, AB (Canada); Henning, A.; Kobussen, S. [Jacobs Nederland BV, Hoogvliet (Netherlands)

    2009-07-01

    Oil sands bitumen contains approximately 4 to 5 per cent sulphur by weight and the bitumen is upgraded to produce lighter fractions. During coking the bitumen is heated and cracked into lighter molecules and a mixture of kerosene, naphtha and gas oil is recovered via fractionation. Then, the vapors leaving the fractionator are processed through hydrodesulphurization, followed by removal by amine based sweetening units. The acid gas from the ASUs is sent to the sulphur recovery units (SRUs) where most of the sulphur is recovered as elemental sulphur. The oil sands industry faces many challenges with respect to environmental impact, energy use and greenhouse gas emissions including the recovery of sulphur and minimizing hydrogen sulfide (H{sub 2}S) and sulphur dioxide (SO{sub 2}) emissions from the oil sands production facilities. In order to improve the SRU control response to acid gas feed variations, Jacobs Comprimo Sulphur Solutions implemented advanced burner control+ (ABC+) at Suncor's Simonette Gas Plant's SRU in northern Alberta. This control system used an acid gas feed analyzer and dynamic algorithms to control the combustion air to the reaction furnace. The analyzer measures H{sub 2}S, total hydrocarbons, carbon dioxide (CO{sub 2}) and water (H{sub 2}O) accurately and quickly, which is important for having effective and fast air-to-acid gas ratio control. The paper provided background information on the Suncor Simonette Gas Plant and discussed ABC+ versus conventional control. An overview of the simplified ABC and ABC+ systems was then illustrated and presented. The ABB multiwave process photometer was also explained. Last, a dynamic simulation of the potential benefits of ABC+ was discussed and the ABC+ benefits for oil sands were presented. It was concluded that ABC+ provides improved SRU performance, reduced SO{sub 2} emissions and violations, and reduced flaring. 1 tab., 3 figs.

  19. Highly stabilized partially premixed flames of propane in a concentric flow conical nozzle burner with coflow

    KAUST Repository

    Elbaz, Ayman M.; Senosy, M.S.; Zayed, M.F.; Roberts, William L.; Mansour, M.S.

    2018-01-01

    . Regardless the value of Φ, increasing the coflow velocity improves the flame stability. The correlation between recessed distance of the burner tubes and the fluctuation of the mixture fraction, Δξ, shows that at Δξ around 40% of the flammability limits leads

  20. Effects of elliptical burner geometry on partially premixed gas jet flames in quiescent surroundings

    Science.gov (United States)

    Baird, Benjamin

    This study is the investigation of the effect of elliptical nozzle burner geometry and partial premixing, both 'passive control' methods, on a hydrogen/hydrocarbon flame. Both laminar and turbulent flames for circular, 3:1, and 4:1 aspect ratio (AR) elliptical burners are considered. The amount of air mixed with the fuel is varied from fuel-lean premixed flames to fuel-rich partially premixed flames. The work includes measurements of flame stability, global pollutant emissions, flame radiation, and flame structure for the differing burner types and fuel conditions. Special emphasis is placed on the near-burner region. Experimentally, both conventional (IR absorption, chemiluminecent, and polarographic emission analysis,) and advanced (laser induced fluorescence, planar laser induced fluorescence, Laser Doppler Velocimetry (LDV), Rayleigh scattering) diagnostic techniques are used. Numerically, simulations of 3-dimensional laminar and turbulent reacting flow are conducted. These simulations are run with reduced chemical kinetics and with a Reynolds Stress Model (RSM) for the turbulence modeling. It was found that the laminar flames were similar in appearance and overall flame length for the 3:1 AR elliptical and the circular burner. The laminar 4:1 AR elliptical burner flame split into two sub-flames along the burner major axis. This splitting had the effect of greatly shortening the 4:1 AR elliptical burner flame to have an overall flame length about half of that of the circular and 3:1 AR elliptical burner flames. The length of all three burners flames increased with increasing burner exit equivalence ratio. The blowout velocity for the three burners increased with increase in hydrogen mass fraction of the hydrogen/propane fuel mixture. For the rich premixed flames, the circular burner was the most stable, the 3:1 AR elliptical burner, was the least stable, and the 4:1 AR elliptical burner was intermediate to the two other burners. This order of stability was due

  1. Pulverized coal burner

    Science.gov (United States)

    Sivy, J.L.; Rodgers, L.W.; Koslosy, J.V.; LaRue, A.D.; Kaufman, K.C.; Sarv, H.

    1998-11-03

    A burner is described having lower emissions and lower unburned fuel losses by implementing a transition zone in a low NO{sub x} burner. The improved burner includes a pulverized fuel transport nozzle surrounded by the transition zone which shields the central oxygen-lean fuel devolatilization zone from the swirling secondary combustion air. The transition zone acts as a buffer between the primary and the secondary air streams to improve the control of near-burner mixing and flame stability by providing limited recirculation regions between primary and secondary air streams. These limited recirculation regions transport evolved NO{sub x} back towards the oxygen-lean fuel pyrolysis zone for reduction to molecular nitrogen. Alternate embodiments include natural gas and fuel oil firing. 8 figs.

  2. Radial lean direct injection burner

    Science.gov (United States)

    Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

    2012-09-04

    A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

  3. Design and analysis of the federal aviation administration next generation fire test burner

    Science.gov (United States)

    Ochs, Robert Ian

    The United States Federal Aviation Administration makes use of threat-based fire test methods for the certification of aircraft cabin materials to enhance the level of safety in the event of an in-flight or post-crash fire on a transport airplane. The global nature of the aviation industry results in these test methods being performed at hundreds of laboratories around the world; in some cases testing identical materials at multiple labs but yielding different results. Maintenance of this standard for an elevated level of safety requires that the test methods be as well defined as possible, necessitating a comprehensive understanding of critical test method parameters. The tests have evolved from simple Bunsen burner material tests to larger, more complicated apparatuses, requiring greater understanding of the device for proper application. The FAA specifies a modified home heating oil burner to simulate the effects of large, intense fires for testing of aircraft seat cushions, cargo compartment liners, power plant components, and thermal acoustic insulation. Recently, the FAA has developed a Next Generation (NexGen) Fire Test burner to replace the original oil burner that has become commercially unavailable. The NexGen burner design is based on the original oil burner but with more precise control of the air and fuel flow rates with the addition of a sonic nozzle and a pressurized fuel system. Knowledge of the fundamental flow properties created by various burner configurations is desired to develop an updated and standardized burner configuration for use around the world for aircraft materials fire testing and airplane certification. To that end, the NexGen fire test burner was analyzed with Particle Image Velocimetry (PIV) to resolve the non-reacting exit flow field and determine the influence of the configuration of burner components. The correlation between the measured flow fields and the standard burner performance metrics of flame temperature and

  4. CHP Integrated with Burners for Packaged Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Castaldini, Carlo; Darby, Eric

    2013-09-30

    division of Sempra Energy. These match funds were provided via concurrent contracts and investments available via CMCE, Altex, and Leva Energy The project attained all its objectives and is considered a success. CMCE secured the support of GI&E from Italy to supply 100 kW Turbec T-100 microturbines for the project. One was purchased by the project’s subcontractor, Altex, and a second spare was purchased by CMCE under this project. The microturbines were then modified to convert from their original recuperated design to a simple cycle configuration. Replacement low-NOx silo combustors were designed and bench tested in order to achieve compliance with the California Air Resources Board (CARB) 2007 emission limits for NOx and CO when in CHP operation. The converted microturbine was then mated with a low NOx burner provided by Altex via an integration section that allowed flow control and heat recovery to minimize combustion blower requirements; manage burner turndown; and recover waste heat. A new fully integrated control system was designed and developed that allowed one-touch system operation in all three available modes of operation: (1) CHP with both microturbine and burner firing for boiler heat input greater than 2 MMBtu/hr; (2) burner head only (BHO) when the microturbine is under service; and (3) microturbine only when boiler heat input requirements fall below 2 MMBtu/hr. This capability resulted in a burner turndown performance of nearly 10/1, a key advantage for this technology over conventional low NOx burners. Key components were then assembled into a cabinet with additional support systems for generator cooling and fuel supply. System checkout and performance tests were performed in the laboratory. The assembled system and its support equipment were then shipped and installed at a host facility where final performance tests were conducted following efforts to secure fabrication, air, and operating permits. The installed power burner is now in commercial

  5. Flow Control

    Science.gov (United States)

    2013-04-08

    can be written as â fj (t) =WO tanh( WIx (t)+bI)+bO, (38) where WI , WO are the input and output matrices, respectively, and bI and bO are the input...applications, present on envisioned airborne optical platforms . One of the problems is that all adaptive optical systems rely on mechanically moving some...of successfully controlling the optical aberration due to the flow over the aperture of airborne optical platforms . As outlined above, systems

  6. A comparison of three turbulence models for axisymmetric isothermal swirling flows in the near burner zone

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstedt, H [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1998-12-31

    In this work three different turbulence models, the k - {epsilon}, RNG k - {epsilon} and Reynolds stress model, have been compared in the case of confined swirling flow. The flow geometries are the isothermal swirling flows measured by International Flame Research Foundation (IFRF). The inlet boundary profiles have been taken from the measurements. At the outlet the effect of furnace end contraction has been studied. The k - {epsilon} model falls to predict the correct flow field. The RNG k - {epsilon} model can provide improvements, although it has problems near the symmetry axis. The Reynolds stress model produces the best agreement with measured data. (author) 13 refs.

  7. A comparison of three turbulence models for axisymmetric isothermal swirling flows in the near burner zone

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstedt, H. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1997-12-31

    In this work three different turbulence models, the k - {epsilon}, RNG k - {epsilon} and Reynolds stress model, have been compared in the case of confined swirling flow. The flow geometries are the isothermal swirling flows measured by International Flame Research Foundation (IFRF). The inlet boundary profiles have been taken from the measurements. At the outlet the effect of furnace end contraction has been studied. The k - {epsilon} model falls to predict the correct flow field. The RNG k - {epsilon} model can provide improvements, although it has problems near the symmetry axis. The Reynolds stress model produces the best agreement with measured data. (author) 13 refs.

  8. Large-eddy simulations of the non-reactive flow in the Sydney swirl burner

    DEFF Research Database (Denmark)

    Yang, Yang; Kær, Søren Knudsen

    2012-01-01

    results. In medium swirling case, there are two reverse-flow regions with a collar-like structure between them. The existence of strong unsteady structure, precessing vortex core, was proven. Coherent structures are detached from the instantaneous field. Q-criterion was used to visualize vorticity field...... with distinct clear structure of vortice tubes. Dominating spatial–temporal structures contained in different cross sections were extracted using proper orthogonal decomposition. In high swirling case, there is only one long reverse-flow region. In this paper, we proved the capability of a commercial CFD...... package in predicting complex flow field and presented the potential of large eddy simulation in understanding dynamics....

  9. Large-eddy simulations of the non-reactive flow in the Sydney swirl burner

    International Nuclear Information System (INIS)

    Yang Yang; Kær, Søren Knudsen

    2012-01-01

    Highlights: ► Rational mesh and grid system for LES are discussed. ► Validated results are provided and discrepancy of mean radial velocity component is discussed. ► Flow structures are identified using vorticity field. ► We performed POD on cross sections to assist in understanding of coherent structures. - Abstract: This paper presents a numerical investigation using large-eddy simulation. Two isothermal cases from the Sydney swirling flame database with different swirl numbers were tested. Rational grid system and mesh details were presented firstly. Validations showed overall good agreement in time averaged results. In medium swirling case, there are two reverse-flow regions with a collar-like structure between them. The existence of strong unsteady structure, precessing vortex core, was proven. Coherent structures are detached from the instantaneous field. Q-criterion was used to visualize vorticity field with distinct clear structure of vortice tubes. Dominating spatial–temporal structures contained in different cross sections were extracted using proper orthogonal decomposition. In high swirling case, there is only one long reverse-flow region. In this paper, we proved the capability of a commercial CFD package in predicting complex flow field and presented the potential of large eddy simulation in understanding dynamics.

  10. Turbulent transport measurements in a cold model of GT-burner at realistic flow rates

    Directory of Open Access Journals (Sweden)

    Gobyzov Oleg

    2016-01-01

    Full Text Available In the present work simultaneous velocity field and passive admixture concentration field measurements at realistic flow-rates conditions in a non-reacting flow in a model of combustion chamber with an industrial mixing device are reported. In the experiments for safety reasons the real fuel (natural gas was replaced with neon gas to simulate stratification in a strongly swirling flow. Measurements were performed by means of planar laser-induced fluorescence (PLIF and particle image velocimetry technique (PIV at Reynolds number, based on the mean flow rate and nozzle diameter, ≈300 000. Details on experimental technique, features of the experimental setup, images and data preprocessing procedures and results of performed measurements are given in the paper. In addition to the raw velocity and admixture concentration data in-depth evaluation approaches aimed for estimation of turbulent kinetic energy (TKE components, assessment of turbulent Schmidt number and analysis of the gradient closure hypothesis from experimental data are presented in the paper.

  11. Efficiency of using direct-flow burners and nozzles in implementation of dry-bottom ash removal at the TPP-210A boiler furnace

    Science.gov (United States)

    Arkhipov, A. M.; Kanunnikov, A. A.; Kirichkov, V. S.; Prokhorov, V. B.; Fomenko, M. V.; Chernov, S. L.

    2017-02-01

    In reconstruction of operating pulverized coal-fired boilers, one of the main factors is the choice of a method for slag removal: dry bottom ash removal (DBAR) or slag-tap removal (STR). In this case, ecological and economic aspects should be taken into account, and also the early ignition of pulverized coal fuel, the reliability of operation of the furnace walls in the mode without slagging, and the stability of slag removal should be provided. In this work, issues of changeover of the pulverized coal-fired boilers of the TPP-210A type from the STR mode to the DBAR mode are considered. As of today, the main problems during the operation of these boilers are the high emissions of nitrogen oxides together with flue gases into the atmosphere and the appropriated payoffs, a small range of loads available, the necessity of stabilization of the pulverizedcoal flame sustainability by using the highly reactive fuel, large mechanical fuel underburning, etc. Results of studying aerodynamics of a furnace with DBAR obtained in the process of physical simulation are given; technical solutions and preliminary design (configuration of burners and nozzles in the boiler furnace, conceptual design of the pulverized coal burner, configuration of TPP-210A boiler with the low heat liberation of furnace cross-section and volumetric heat release) are set forth, which are associated with the optimization of aerodynamics of furnace volume, when the direct-flow burners and nozzles are used, and with organization of the efficient staged combustion of solid fuel. Two versions of possible modernization of a boiler unit are considered. Under conditions of the planned increase in the steam production capacity, the most promising measures are as follows: the DBAR implementation with reducing heat releases of the cross-section and volume of the furnace approximately by half, the installation of the direct-flow burners and nozzles with injection of recirculation gases into the active combustion

  12. Effect of the mixing fields on the stability and structure of turbulent partially premixed flames in a concentric flow conical nozzle burner

    KAUST Repository

    Mansour, Mohy S.

    2016-10-22

    The mixing field is known to be one of the key parameters that affect the stability and structure of partially premixed flames. Data in these flames are now available covering the effects of turbulence, combustion system geometry, level of partially premixing and fuel type. However, quantitative analyses of the flame structure based on the mixing field are not yet available. The aim of this work is to present a comprehensive study of the effects of the mixing fields on the structure and stability of partially premixed methane flames. The mixing field in a concentric flow conical nozzle (CFCN) burner with well-controlled mechanism of the mixing is investigated using Rayleigh scattering technique. The flame stability, structure and flow field of some selected cases are presented using LIF of OH and PIV. The experimental data of the mixing field cover wide ranges of Reynolds number, equivalence ratio and mixing length. The data show that the mixing field is significantly affected by the mixing length and the ratio of the air-to-fuel velocities. The Reynolds number has a minimum effect on the mixing field in high turbulent flow regime and the stability is significantly affected by the turbulence level. The temporal fluctuations of the range of mixture fraction within the mixing field correlate with the flame stability. The highest point of stability occurs at recess distances where fluid mixtures near the jet exit plane are mostly within the flammability limits. This paper provides some correlations between the stability range in mixture fraction space and the turbulence level for different equivalence ratios.

  13. Parameter optimization through performance analysis of model based control of a batch heat treatment furnace with low NO x radiant tube burner

    International Nuclear Information System (INIS)

    Tiwari, Manish Kumar; Mukhopadhyay, Achintya; Sanyal, Dipankar

    2005-01-01

    A model based control structure for heat treating a 0.5% C steel slab in a batch furnace with low NO x radiant tube burner is designed and tested for performance to yield optimal parameter values using the model developed in the companion paper. Combustion is considered in a highly preheated and product gas diluted mode. Controlled combustion with a proposed arrangement for preheating and diluting the air by recirculating the exhaust gas that can be retrofitted with an existing burner yields satisfactory performance and emission characteristics. Finally, the effect of variable property considerations are presented and critically analyzed

  14. Pulsed fan burner units with integrated automatic lambda control. Pt. 2; Impulsgeblaesebrennaggregate mit integrierter LAMBDA-Automatik. T. 2

    Energy Technology Data Exchange (ETDEWEB)

    Kiem, Ralph

    2010-02-15

    In recent years, pulsed firing technology has gained increasing importance in the ceramic industry for optimizing firing quality while saving energy through the use of PLC technology. To satisfy ever more stringent environmental regulations, including the German Technical Instructions on Air Quality Control (TA Luft) and the Federal Immission Control Act (Blmschg), the further improvement of proven systems currently in use is absolutely essential. Pulsed fan burners with automatic combustion-air adjustment are the development engineers' response to the need for flexibly automated turbulences in the combustion atmosphere that comply with statutory emission standards. In addition, energy savings of some 20% can be achieved with this technology compared to the older pulsed combustion systems. (orig.)

  15. Numerical simulation of porous burners and hole plate surface burners

    Directory of Open Access Journals (Sweden)

    Nemoda Stevan

    2004-01-01

    Full Text Available In comparison to the free flame burners the porous medium burners, especially those with flame stabilization within the porous material, are characterized by a reduction of the combustion zone temperatures and high combustion efficiency, so that emissions of pollutants are minimized. In the paper the finite-volume numerical tool for calculations of the non-isothermal laminar steady-state flow, with chemical reactions in laminar gas flow as well as within porous media is presented. For the porous regions the momentum and energy equations have appropriate corrections. In the momentum equations for the porous region an additional pressure drop has to be considered, which depends on the properties of the porous medium. For the heat transfer within the porous matrix description a heterogeneous model is considered. It treats the solid and gas phase separately, but the phases are coupled via a convective heat exchange term. For the modeling of the reaction of the methane laminar combustion the chemical reaction scheme with 164 reactions and 20 chemical species was used. The proposed numerical tool is applied for the analyses of the combustion and heat transfer processes which take place in porous and surface burners. The numerical experiments are accomplished for different powers of the porous and surface burners, as well as for different heat conductivity character is tics of the porous regions.

  16. Intelligent Flow Control Valve

    Science.gov (United States)

    Kelley, Anthony R (Inventor)

    2015-01-01

    The present invention is an intelligent flow control valve which may be inserted into the flow coming out of a pipe and activated to provide a method to stop, measure, and meter flow coming from the open or possibly broken pipe. The intelligent flow control valve may be used to stop the flow while repairs are made. Once repairs have been made, the valve may be removed or used as a control valve to meter the amount of flow from inside the pipe. With the addition of instrumentation, the valve may also be used as a variable area flow meter and flow controller programmed based upon flowing conditions. With robotic additions, the valve may be configured to crawl into a desired pipe location, anchor itself, and activate flow control or metering remotely.

  17. Distributed Power Flow Controller

    NARCIS (Netherlands)

    Yuan, Z.

    2010-01-01

    In modern power systems, there is a great demand to control the power flow actively. Power flow controlling devices (PFCDs) are required for such purpose, because the power flow over the lines is the nature result of the impedance of each line. Due to the control capabilities of different types of

  18. Non-uniform velocity profile mechanism for flame stabilization in a porous radiant burner

    Energy Technology Data Exchange (ETDEWEB)

    Catapan, R.C.; Costa, M. [Mechanical Engineering Department, Instituto Superior Tecnico, Technical University of Lisbon, Avenida Rovisco Pais, 1049-001 Lisbon (Portugal); Oliveira, A.A.M. [Mechanical Engineering Department, Federal University of Santa Catarina, Campus Universitario Professor Joao David Ferreira Lima, 88040-900 Florianopolis, SC (Brazil)

    2011-01-15

    Industrial processes where the heating of large surfaces is required lead to the possibility of using large surface porous radiant burners. This causes additional temperature uniformity problems, since it is increasingly difficult to evenly distribute the reactant mixture over a large burner surface while retaining its stability and keeping low pollutant emissions. In order to allow for larger surface area burners, a non-uniform velocity profile mechanism for flame stabilization in a porous radiant burner using a single large injection hole is proposed and analyzed for a double-layered burner operating in open and closed hot (laboratory-scale furnace, with temperature-controlled, isothermal walls) environments. In both environments, local mean temperatures within the porous medium have been measured. For lower reactant flow rate and ambient temperature the flame shape is conical and anchored at the rim of the injection hole. As the volumetric flow rate or furnace temperature is raised, the flame undergoes a transition to a plane flame stabilized near the external burner surface. However, the stability range envelope remains the same in both regimes. (author)

  19. Industrial burner and process efficiency program

    Science.gov (United States)

    Huebner, S. R.; Prakash, S. N.; Hersh, D. B.

    1982-10-01

    There is an acute need for a burner that does not use excess air to provide the required thermal turndown and internal recirculation of furnace gases in direct fired batch type furnaces. Such a burner would improve fuel efficiency and product temperature uniformity. A high velocity burner has been developed which is capable of multi-fuel, preheated air, staged combustion. This burner is operated by a microprocessor to fire in a discrete pulse mode using Frequency Modulation (FM) for furnace temperature control by regulating the pulse duration. A flame safety system has been designed to monitor the pulse firing burners using Factory Mutual approved components. The FM combustion system has been applied to an industrial batch hardening furnace (1800 F maximum temperature, 2500 lbs load capacity).

  20. Defining Quantum Control Flow

    OpenAIRE

    Ying, Mingsheng; Yu, Nengkun; Feng, Yuan

    2012-01-01

    A remarkable difference between quantum and classical programs is that the control flow of the former can be either classical or quantum. One of the key issues in the theory of quantum programming languages is defining and understanding quantum control flow. A functional language with quantum control flow was defined by Altenkirch and Grattage [\\textit{Proc. LICS'05}, pp. 249-258]. This paper extends their work, and we introduce a general quantum control structure by defining three new quantu...

  1. Fluid flow control system

    International Nuclear Information System (INIS)

    Rion, Jacky.

    1982-01-01

    Fluid flow control system featuring a series of grids placed perpendicular to the fluid flow direction, characterized by the fact that it is formed of a stack of identical and continuous grids, each of which consists of identical meshes forming a flat lattice. The said meshes are offset from one grid to the next. This system applies in particular to flow control of the coolant flowing at the foot of an assembly of a liquid metal cooled nuclear reactor [fr

  2. Integrated solar-assisted heat pumps for water heating coupled to gas burners; control criteria for dynamic operation

    International Nuclear Information System (INIS)

    Scarpa, F.; Tagliafico, L.A.; Tagliafico, G.

    2011-01-01

    A direct expansion integrated solar-assisted heat pump (ISAHP) is compared to a traditional flat plate solar panel for low temperature (45 deg. C) water heating applications. The (simulated) comparison is accomplished assuming both the devices are energy supplemented with an auxiliary standard gas burner, to provide the typical heat duty of a four-member family. Literature dynamical models of the systems involved have been used to calculate the main performance figures in a context of actual climatic conditions and typical stochastic user demand. The paper highlights new heat pump control concepts, needed when maximum energy savings are the main goal of the apparatus for given user demand. Simulations confirm the high collector efficiency of the ISAHP when its panel/evaporator works at temperature close to the ambient one. The device, with respect to a flat plate solar water heater, shows a doubled performance, so that it can do the same task just using an unglazed panel with roughly half of the surface.

  3. Performance and analysis by particle image velocimetry (PIV) of cooker-top burners in Thailand

    International Nuclear Information System (INIS)

    Makmool, U.; Jugjai, S.; Tia, S.; Vallikul, P.; Fungtammasan, B.

    2007-01-01

    Cooker-top burners are used extensively in Thailand because of the rapid combustion and high heating-rates created by an impinging flame, which is characteristic of these types of burners. High thermal efficiency with low level of CO emissions is the most important performance criteria for these burners. The wide variation in reported performances of the burners appears to be due to the ad hoc knowledge gained through trial and error of the local manufacturers rather than sound scientific principles. This is extremely undesirable in view of safety, energy conservation and environmental protection. In the present work, a nationwide cooker-top burner performance survey and an implementation of a PIV technique to analyze the burner performance as well as advising local manufacturers were carried out. Experimental data were reported for the base line value of thermal efficiency of all the burners. The thermal performance parameters and dynamic properties of the flow field at a flame impingement area, i.e. velocity magnitude, turbulent intensity, vorticity and strain rate were also reported as a function of burner type, which was categorized into four types based on the configuration of the burner head: radial flow burners, swirling flow burners, vertical flow burners and porous radiant burners

  4. LOW NOX BURNER DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    KRISHNA,C.R.; BUTCHER,T.

    2004-09-30

    The objective of the task is to develop concepts for ultra low NOx burners. One approach that has been tested previously uses internal recirculation of hot gases and the objective was to how to implement variable recirculation rates during burner operation. The second approach was to use fuel oil aerosolization (vaporization) and combustion in a porous medium in a manner similar to gas-fired radiant burners. This task is trying the second approach with the use of a somewhat novel, prototype system for aerosolization of the liquid fuel.

  5. LES and experimental studies of cold and reacting flow in a swirled partially remixed burner with and without fuel modulation

    NARCIS (Netherlands)

    Sengissen, A.X.; van Kampen, J.F.; Huls, R.A.; Stoffels, Genie G.M.; Kok, Jacobus B.W.; Poinsot, T.J.

    2007-01-01

    In devices where air and fuel are injected separately, combustion processes are influenced by oscillations of the air flow rate but may also be sensitive to fluctuations of the fuel flow rate entering the chamber. This paper describes a joint experimental and numerical study of the mechanisms

  6. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS

    Energy Technology Data Exchange (ETDEWEB)

    E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; T.H. Fletcher; H. Zhang; K.A. Davis; M. Denison; H. Shim

    2002-01-01

    The focus of this program is to provide insight into the formation and minimization of NO{sub x} in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO{sub x} emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames--particularly under low NO{sub x} conditions. A CO/H{sub 2}/O{sub 2}/N{sub 2} flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state {sup 13}C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that

  7. MINIMIZATION OF NO EMISSIONS FROM MULTI-BURNER COAL-FIRED BOILERS; FINAL

    International Nuclear Information System (INIS)

    E.G. Eddings; A. Molina; D.W. Pershing; A.F. Sarofim; T.H. Fletcher; H. Zhang; K.A. Davis; M. Denison; H. Shim

    2002-01-01

    The focus of this program is to provide insight into the formation and minimization of NO(sub x) in multi-burner arrays, such as those that would be found in a typical utility boiler. Most detailed studies are performed in single-burner test facilities, and may not capture significant burner-to-burner interactions that could influence NO(sub x) emissions. Thus, investigations of such interactions were made by performing a combination of single and multiple burner experiments in a pilot-scale coal-fired test facility at the University of Utah, and by the use of computational combustion simulations to evaluate full-scale utility boilers. In addition, fundamental studies on nitrogen release from coal were performed to develop greater understanding of the physical processes that control NO formation in pulverized coal flames-particularly under low NO(sub x) conditions. A CO/H(sub 2)/O(sub 2)/N(sub 2) flame was operated under fuel-rich conditions in a flat flame reactor to provide a high temperature, oxygen-free post-flame environment to study secondary reactions of coal volatiles. Effects of temperature, residence time and coal rank on nitrogen evolution and soot formation were examined. Elemental compositions of the char, tar and soot were determined by elemental analysis, gas species distributions were determined using FTIR, and the chemical structure of the tar and soot was analyzed by solid-state(sup 13)C NMR spectroscopy. A laminar flow drop tube furnace was used to study char nitrogen conversion to NO. The experimental evidence and simulation results indicated that some of the nitrogen present in the char is converted to nitric oxide after direct attack of oxygen on the particle, while another portion of the nitrogen, present in more labile functionalities, is released as HCN and further reacts in the bulk gas. The reaction of HCN with NO in the bulk gas has a strong influence on the overall conversion of char-nitrogen to nitric oxide; therefore, any model that

  8. Flow Characteristics of Multi-circular Jet Plate in Premix Chamber of Air-Assist Atomizer for Burner System

    Directory of Open Access Journals (Sweden)

    Amirnordin Shahrin Hisham

    2016-01-01

    Full Text Available The flow characteristics of multi-circular jet (MCJ plate in the premix chamber of an atomizer were investigated using Computational Fluid Dynamics. Multiphase volume of fluid behavior inside the chamber was determined via steady simulations. The Eulerian–Eulerian two-fluid approach was used for execution mixing of diesel fuel and air. Spray simulation using the discrete phase with injection was generated from the nozzle hole into the ambient atmosphere. The behavior of three MCJ plates in the premix chamber was studied numerically. Results illustrated that plate open area, Ae, influenced the turbulence inside the chamber. MCJ 3, which had the lowest open area, generated the highest flow velocity and turbulence kinetic energy compared with MCJ 1 and 2. The MCJ plates could increase the turbulence in the premix chamber and contribute to the combustion efficiency.

  9. Environmental control implications of generating electric power from coal. 1977 technology status report. Appendix D. Assessment of NO/sub x/ control technology for coal fired utility boilers. [Low-excess-air, staged combustion, flu gas recirculation and burner design

    Energy Technology Data Exchange (ETDEWEB)

    1977-12-01

    An NOx control technology assessment study was conducted to examine the effectiveness of low-excess-air firing, staged combustion, flue gas recirculation, and current burner/boiler designs as applied to coal-fired utility boilers. Significant variations in NOx emissions exist with boiler type, firing method, and coal type, but a relative comparison of emissions control performance, cost, and operational considerations is presented for each method. The study emphasized the numerous operational factors that are of major importance to the user in selecting and implementing a combustion modification technique. Staged combustion and low-excess-air operation were identified as the most cost-effective methods for existing units. Close control of local air/fuel ratios and rigorous combustion equipment maintenance are essential to the success of both methods. Flue gas recirculation is relatively ineffective and has the added concern of tube erosion. More research is needed to resolve potential corrosion concerns with low-NOx operating modes. Low-NOx burners in conjunction with a compartmentalized windbox are capable of meeting a 0.6-lb/million Btu emission level on new units. Advanced burner designs are being developed to meet research emission goals of approximately 0.25 lb/MBtu.

  10. Design process and instrumentation of a low NOx wire-mesh duct burner for micro-cogeneration unit

    Energy Technology Data Exchange (ETDEWEB)

    Ramadan, O.B.; Gauthier, J.E.D. [Carleton Univ., Ottawa, ON (Canada). Dept. of Mechanical and Aerospace Engineering; Hughes, P.M.; Brandon, R. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre

    2007-07-01

    Air pollution and global climate change have become a serious environmental problem leading to increasingly stringent government regulations worldwide. New designs and methods for improving combustion systems to minimize the production of toxic emissions, like nitrogen oxides (NOx) are therefore needed. In order to control smog, acid rain, ozone depletion, and greenhouse-effect warming, a reduction of nitrogen oxide is necessary. One alternative for combined electrical power and heat generation (CHP) are micro-cogeneration units which use a micro-turbine as a prime mover. However, to increase the efficiencies of these units, micro-cogeneration technology still needs to be developed further. This paper described the design process, building, and testing of a new low NOx wire-mesh duct burner (WMDB) for the development of a more efficient micro-cogeneration unit. The primary goal of the study was to develop a practical and simple WMDB, which produces low emissions by using lean-premixed surface combustion concept and its objectives were separated into four phases which were described in this paper. Phase I involved the design and construction of the burner. Phase II involved a qualitative flow visualization study for the duct burner premixer to assist the new design of the burner by introducing an efficient premixer that could be used in this new application. Phase III of this research program involved non-reacting flow modeling on the burner premixer flow field using a commercial computational fluid dynamic model. In phase IV, the reacting flow experimental investigation was performed. It was concluded that the burner successfully increased the quantity and the quality of the heat released from the micro-CHP unit and carbon monoxide emissions of less than 9 ppm were reached. 3 refs., 3 figs.

  11. Influence of staged-air on airflow, combustion characteristics and NO(x) emissions of a down-fired pulverized-coal 300 MW(e) utility boiler with direct flow split burners.

    Science.gov (United States)

    Li, Zhengqi; Kuang, Min; Zhang, Jia; Han, Yunfeng; Zhu, Qunyi; Yang, Lianjie; Kong, Weiguang

    2010-02-01

    Cold airflow experiments were conducted to investigate the aerodynamic field in a small-scale furnace of a down-fired pulverized-coal 300 MW(e) utility boiler arranged with direct flow split burners enriched by cyclones. By increasing the staged-air ratio, a deflected flow field appeared in the lower furnace; larger staged-air ratios produced larger deflections. Industrial-sized experiments on a full-scale boiler were also performed at different staged-air damper openings with measurements taken of gas temperatures in the burner region and near the right-side wall, wall heat fluxes, and gas components (O(2), CO, and NO(x)) in the near-wall region. Combustion was unstable at staged-air damper openings below 30%. For openings of 30% and 40%, late ignition of the pulverized coal developed and large differences arose in gas temperatures and heat fluxes between the regions near the front and rear walls. In conjunction, carbon content in the fly ash was high and boiler efficiency was low with high NO(x) emission above 1200 mg/m(3) (at 6% O(2) dry). For fully open dampers, differences in gas temperatures and heat fluxes, carbon in fly ash and NO(x) emission decreased yielding an increase in boiler efficiency. The optimal setting is fully open staged-air dampers.

  12. Content dependent information flow control

    DEFF Research Database (Denmark)

    Nielson, Hanne Riis; Nielson, Flemming

    2017-01-01

    Information flow control extends access control by not only regulating who is allowed to access what data but also the subsequent use of the data. Applications within communications systems require such information flow control to be dependent on the actual contents of the data. We develop...

  13. Effects of Burner Configurations on the Natural Oscillation Characteristics of Laminar Jet Diffusion Flames

    Directory of Open Access Journals (Sweden)

    K. R. V. Manikantachari

    2015-09-01

    Full Text Available In this work, effects of burner configurations on the natural oscillations of methane laminar diffusion flames under atmospheric pressure and normal gravity conditions have been studied experimentally. Three regimes of laminar diffusion flames, namely, steady, intermittent flickering and continuous flickering have been investigated. Burner configurations such as straight pipe, contoured nozzle and that having an orifice plate at the exit have been considered. All burners have the same area of cross section at the exit and same burner lip thickness. Flame height data has been extracted from direct flame video using MATLAB. Shadowgraph videos have been captured to analyze the plume width characteristics. Results show that, the oscillation characteristics of the orifice burner is significantly different from the other two burners; orifice burner produces a shorter flame and wider thermal plume width in the steady flame regime and the onset of the oscillation/flickering regimes for the orifice burner occurs at a higher fuel flow rate. In the natural flickering regime, the dominating frequency of flame flickering remains within a small range, 12.5 Hz to 15 Hz, for all the burners and for all fuel flow rates. The time-averaged flame length-scale parameters, such as the maximum and the minimum flame heights, increase with respect to the fuel flow rate, however, the difference in the maximum and the minimum flame heights remains almost constant.

  14. High conversion burner type reactor

    International Nuclear Information System (INIS)

    Higuchi, Shin-ichi; Kawashima, Masatoshi

    1987-01-01

    Purpose: To simply and easily dismantle and reassemble densified fuel assemblies taken out of a high conversion ratio area thereby improve the neutron and fuel economy. Constitution: The burner portion for the purpose of fuel combustion is divided into a first burner region in adjacent with the high conversion ratio area at the center of the reactor core, and a second burner region formed to the outer circumference thereof and two types of fuels are charged therein. Densified fuel assemblies charged in the high conversion ratio area are separatably formed as fuel assemblies for use in the two types of burners. In this way, dense fuel assembly is separated into two types of fuel assemblies for use in burner of different number and arranging density of fuel elements which can be directly charged to the burner portion and facilitate the dismantling and reassembling of the fuel assemblies. Further, since the two types of fuel assemblies are charged in the burner portion, utilization factor for the neutron fuels can be improved. (Kamimura, M.)

  15. Characterization of combustion in a fabric singeing burner operating with varsol

    International Nuclear Information System (INIS)

    Quintana M, Juan C; Mendoza S, Cesar Camilo; Molina Alejandro

    2009-01-01

    The textile industry uses singeing burners to diminish the amount of pilling on surface fabrics. Some of these burners use Stoddard solvent which has high cost per unit of energy, high flammability and emits volatile organic compounds that pose an occupational safety hazard. This study characterized a singing burner operating with varsol performing measurements of temperature downstream the burner, air and fuel flows, and concentration of CO, CO 2 , O 2 and NO x . These measurements defined the most important characteristics of the Stoddard solvent flame that should be maintained to obtain a similar behavior in an eventual change to natural gas.

  16. Research on the Improvement of a Natural Gas Fired Burner for the CHP Application in a Central Heating Boiler using Radiant Burner Technology

    Energy Technology Data Exchange (ETDEWEB)

    Bieleveld, T.

    2010-08-15

    These days, the reduction of CO2 emissions from combustion devices is one of the main priorities for each design improvement. For the domestic use of the central heating boiler, Microgen Engine Corporation produces free piston Stirling engines for the Combined Heat and Power (CHP) application in these central heating boilers (Dutch: 'HRe ketel'). With CHP, the generation of electricity and heat are combined to increase overall efficiency, as heat is generally a waste product from the combustion to electric generation process. In this application, the Stirling engine, which can be defined as an external combustion engine, is heated by a natural gas fired engine-burner and cooled by a coolant flow. The heat transfer into the engine is converted into mechanical work and a heat flux from the engine. The mechanical work is used to produce electricity via a linear alternator. Heat in the flue gasses from the engine-burner is reused in a secondary burner and condensing heat exchanger. The coolant flow from the engine, after passing the secondary burner, is used for heating purposes. The heat transfer from engine-burner to the Stirling engine is analyzed and via several motivations it is found that it is favorable to improve fuel to electric conversion efficiency, for which the heat transfer efficiency of the engine-burner to the Stirling engine should be improved, as the engine design is not to be altered. From an initially developed linear free piston Stirling engine model and measurements performed at Microgen Engine Corporation, St. Petersborough, (UK), the engine power demand and engine-burner performance are found. The results are used to visualize the current energy flows of the Stirling engine and engine burner subsystem. The heat transfer to the engine is analyzed to find possible heat transfer improvements. It is concluded that heat transfer from the engine-burner to the engine can be approved if the flue losses due to convective heat transfer are

  17. Flow Control Technology

    Science.gov (United States)

    2010-07-01

    known as Darrieus turbines or, after the German inventors of these devices, Voith-Schneider propellers. Their main advantage is the ability to produce... turbines (VAWT), named for the typical orientation of the main shaft. While their efficiency is similar to that of the more common horizontal axis wind ...Oscillating Systems’, Cambridge University Press, 2002 [11] G. M. Darrieus , ’ Turbine having its rotating shaft transverse to the flow of the current

  18. Low NO sub x /SO sub x Burner retrofit for utility cyclone boilers

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This Public Design Report provides available nonproprietary design information on the Low NO{sub x}SO{sub x} Burner Retrofit of Utility Cyclone Boilers project. In addition to the design aspects, the history of the project, the organization of the project, and the role of the funding parties are discussed. An overview of the Low NO{sub x}SO{sub x} (LNS) Burner, the cyclone boiler and the Southern Illinois Power Cooperative host site is presented. A detailed nonproprietary description of the individual process steps, plant systems, and resulting performance then follows. Narrative process descriptions, simplified process flow diagrams, input/output stream data, operating conditions and requirements are given for each unit. The plant demonstration program and start up provisions, the environmental considerations and control, monitoring and safety factors that are considered are also addressed.

  19. Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

    Science.gov (United States)

    Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

    2002-01-01

    A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

  20. Flow Control Enabled Aircraft Design

    National Research Council Canada - National Science Library

    Nangia, Rajendar

    2004-01-01

    ...: Many future advanced aircraft concepts being considered by the Air Force fall outside the current aerodynamic design practice and will rely heavily on the use of flow control technology to optimize flight performance...

  1. Slurry burner for mixture of carbonaceous material and water

    Science.gov (United States)

    Nodd, D.G.; Walker, R.J.

    1985-11-05

    The present invention is intended to overcome the limitations of the prior art by providing a fuel burner particularly adapted for the combustion of carbonaceous material-water slurries which includes a stationary high pressure tip-emulsion atomizer which directs a uniform fuel into a shearing air flow as the carbonaceous material-water slurry is directed into a combustion chamber, inhibits the collection of unburned fuel upon and within the atomizer, reduces the slurry to a collection of fine particles upon discharge into the combustion chamber, and regulates the operating temperature of the burner as well as primary air flow about the burner and into the combustion chamber for improved combustion efficiency, no atomizer plugging and enhanced flame stability.

  2. Optimal Power Flow Control by Rotary Power Flow Controller

    Directory of Open Access Journals (Sweden)

    KAZEMI, A.

    2011-05-01

    Full Text Available This paper presents a new power flow model for rotary power flow controller (RPFC. RPFC injects a series voltage into the transmission line and provides series compensation and phase shifting simultaneously. Therefore, it is able to control the transmission line impedance and the active power flow through it. An RPFC is composed mainly of two rotary phase shifting transformers (RPST and two conventional (series and shunt transformers. Structurally, an RPST consists of two windings (stator and rotor windings. The rotor windings of the two RPSTs are connected in parallel and their stator windings are in series. The injected voltage is proportional to the vector sum of the stator voltages and so its amplitude and angle are affected by the rotor position of the two RPSTs. This paper, describes the steady state operation and single-phase equivalent circuit of the RPFC. Also in this paper, a new power flow model, based on power injection model of flexible ac transmission system (FACTS controllers, suitable for the power flow analysis is introduced. Proposed model is used to solve optimal power flow (OPF problem in IEEE standard test systems incorporating RPFC and the optimal settings and location of the RPFC is determined.

  3. Enhanced Combustion Low NOx Pulverized Coal Burner

    Energy Technology Data Exchange (ETDEWEB)

    David Towle; Richard Donais; Todd Hellewell; Robert Lewis; Robert Schrecengost

    2007-06-30

    For more than two decades, Alstom Power Inc. (Alstom) has developed a range of low cost, infurnace technologies for NOx emissions control for the domestic U.S. pulverized coal fired boiler market. This includes Alstom's internally developed TFS 2000{trademark} firing system, and various enhancements to it developed in concert with the U.S. Department of Energy. As of the date of this report, more than 270 units representing approximately 80,000 MWe of domestic coal fired capacity have been retrofit with Alstom low NOx technology. Best of class emissions range from 0.18 lb/MMBtu for bituminous coal to 0.10 lb/MMBtu for subbituminous coal, with typical levels at 0.24 lb/MMBtu and 0.13 lb/MMBtu, respectively. Despite these gains, NOx emissions limits in the U.S. continue to ratchet down for new and existing boiler equipment. On March 10, 2005, the Environmental Protection Agency (EPA) announced the Clean Air Interstate Rule (CAIR). CAIR requires 25 Eastern states to reduce NOx emissions from the power generation sector by 1.7 million tons in 2009 and 2.0 million tons by 2015. Low cost solutions to meet such regulations, and in particular those that can avoid the need for a costly selective catalytic reduction system (SCR), provide a strong incentive to continue to improve low NOx firing system technology to meet current and anticipated NOx control regulations. The overall objective of the work is to develop an enhanced combustion, low NOx pulverized coal burner, which, when integrated with Alstom's state-of-the-art, globally air staged low NOx firing systems will provide a means to achieve: Less than 0.15 lb/MMBtu NOx emissions when firing a high volatile Eastern or Western bituminous coal, Less than 0.10 lb/MMBtu NOx emissions when firing a subbituminous coal, NOx reduction costs at least 25% lower than the costs of an SCR, Validation of the NOx control technology developed through large (15 MWt) pilot scale demonstration, and Documentation required for

  4. Subcubic Control Flow Analysis Algorithms

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Van Horn, David

    We give the first direct subcubic algorithm for performing control flow analysis of higher-order functional programs. Despite the long held belief that inclusion-based flow analysis could not surpass the ``cubic bottleneck, '' we apply known set compression techniques to obtain an algorithm...... that runs in time O(n^3/log n) on a unit cost random-access memory model machine. Moreover, we refine the initial flow analysis into two more precise analyses incorporating notions of reachability. We give subcubic algorithms for these more precise analyses and relate them to an existing analysis from...

  5. Controls on summer low flow

    Science.gov (United States)

    Graham, C. B.; McNamara, J. P.

    2012-12-01

    Summer low flow has significant impacts on aquatic flora and fauna, municipal water use, and power generation. However, the controls on the minimum annual summer discharge are complex, including a combination of snowmelt dynamics, summer evapotranspiration demand, and spring, summer precipitation patterns and surface - groundwater interactions. This is especially true in the Rocky Mountain West of the United States, where snowpack provides the majority of water available for spring runoff and groundwater replenishment. In this study, we look at summer low flow conditions at four snow dominated catchments (26 km2 - 2200 km2) in South-central Idaho currently feeling the effects of climate change. Measures of snowmelt dynamics, summer evapotranspiration demand and spring and summer precipitation are used to determine the dominant controls on late summer low flow magnitude, timing and duration. These analyses show that the controls vary between watersheds, with significant implications for the impacts of climate change in snow dominated areas of the Rocky Mountain West.

  6. Developement of porous media burner operating on waste vegetable oil

    International Nuclear Information System (INIS)

    Lapirattanakun, Arwut; Charoensuk, Jarruwat

    2017-01-01

    Highlights: • Steam was successfully applied to promote combustion of WVO. • A specially designed porous domain was an essential element for stable combustion of WVO. • The performance of WVO burner was in the range of cooking stove. • Nozzle clog up in domestic WVO burner can be avoided when replacing it with a steam-assisted nozzle. - Abstract: A newly designed cooking stove using Wasted Vegetable Oil (WVO) as fuel was introduced. Porous media, containing 2 cm diameter of spherical ceramic balls, was used as a flame stabilizer. Steam was successfully applied in a burner at this scale to atomize WVO droplet and entrain air into the combustion zone as well as to reduce soot and CO emission. DIN EN 203-1 testing standard was adopted and the experiment was conducted at various firing rate with the water flow rate at 0.16, 0.20 and 0.22 kg/min. Temperature, emissions, visible flame length, thermal efficiency as well as combustion efficiency were evaluated. Under the current WVOB design, it was suitable to operate the burner at the range of nominal firing rate between 325 and 548 kW/m"2 with water flow rate of 0.16 kg/min, at burner height to diameter ratio of 0.75, giving CO and NO_x emissions up to 171 and 40 ppm, respectively (at 6% O_2). Thermal efficiency was at around 28% where the combustion efficiency was approximately at 99.5%. The performance of WVO burner could be improved further if increasing the H/D ratio to 1.5, yielding thermal efficiency up to 42%.

  7. Altitude Performance Characteristics of Tail-pipe Burner with Convergingconical Burner Section on J47 Turbojet Engine

    Science.gov (United States)

    Prince, William R; Mcaulay, John E

    1950-01-01

    An investigation of turbojet-engine thrust augmentation by means of tail-pipe burning was conducted in the NACA Lewis altitude wind tunnel. Performance data were obtained with a tail-pipe burner having a converging conical burner section installed on an axial-flow-compressor type turbojet engine over a range of simulated flight conditions and tail-pipe fuel-air ratios with a fixed-area exhaust nozzle. A maximum tail-pipe combustion efficiency of 0.86 was obtained at an altitude of 15,000 feet and a flight Mach number of 0.23. Tail-pipe burner operation was possible up to an altitude of 45,000 feet at a flight Mach number of 0.23.

  8. Flow control arrangements for centrifuges

    International Nuclear Information System (INIS)

    Alderton, G.W.; Davidge, P.C.

    1983-01-01

    In a centrifuge plant for the separation of uranium isotopes, when a centrifuge machine breaks down, light gas is produced. This gas can cause adjacent machines to break down, so propagating the fault. The present invention provides flow control arrangements in gas pipes to the centrifuge, whereby sudden egress of gas from a failed machine is inhibited. (author)

  9. The method of waste liquid atomization/incineration by using ultrasonic industrial burners

    International Nuclear Information System (INIS)

    Bartonek, Thomas

    1999-01-01

    The problem of burning a fuel is closely related to distributing that fuel and mixing it with the combustion air within a pre-designated space, the combustion chamber. For fuel engineers, the rule of thumb is unchanged: mix it and it will burn. That is why the burner designer focuses his attention on incorporating the best possible atomization and mixing, equipment, i.c. in the end, on the construction of the atomizer nozzle and the control of the combustion air. It was these considerations plus the inability of conventional burners to meet the tough demands of today's applications that led DUMAG to undertake an intensive program of research which has now been crowned with success. Below, basic points drawn from the fundamental knowledge of all fuel engineers have been included to bring into sharper focus the operating principles of the DUMAG Ultrasonic Industrial Burner, a world class Austrian product. This paper describes a plant which has been operating without incident since October 1977. Its level of operational effectiveness is at least equivalent to that of a standard oil burner plant. The plant is also in full compliance with current environmental standards following the installation of additional safety equipment such as pre-combustion chambers, sensors to monitor pre-combustion chamber temperatures, cut-off valves for reaction water and solvents to block their flow if no heating oil is being fed in, flue gas density monitor, and finer atomization and better mixing by means of an ultrasonic system - even with fluctuations in the viscosity. By eliminating disposal costs and recovering power from liquid waste materials, the entire plant pays for itself within one year. (Original)

  10. Blow-off characteristics of turbulent premixed flames in curved-wall Jet Burner

    KAUST Repository

    Mansour, Morkous S.; Mannaa, O.; Chung, Suk-Ho

    2015-01-01

    and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the turbulent flow field features. Ethylene/air flames were stabilized in CWJ burner to determine the sequence of events leading to blowoff. For stably burning flames far from blowoff

  11. IEN project - Fluidized bed burner

    International Nuclear Information System (INIS)

    1985-08-01

    Due to difficulties inherent to the organic waste storage from laboratories and institutes which use radioactive materials for scientific researches, the Nuclear Facilities Division (DIN/CNEN); elaborated a project for constructing a fluidized burner, in laboratory scale, for burning the low level organic radioactive wastes. The burning system of organic wastes is described. (M.C.K.) [pt

  12. Optimisation of efficiency and emissions in pellet burners

    International Nuclear Information System (INIS)

    Eskilsson, David; Roennbaeck, Marie; Samuelsson, Jessica; Tullin, Claes

    2004-01-01

    There is a trade-off between the emissions of nitrogen oxides (NO x ) and of unburnt hydrocarbons and carbon monoxide (OGC and CO). Decreasing the excess air results in lower NO x emission but also increased emission of unburnt. The efficiency increases, as the excess air is decreased until the losses due to incomplete combustion become too high. The often-high NO x emission in today's pellet burners can be significantly reduced using well-known techniques such as air staging. The development of different chemical sensors is very intensive and recently sensors for CO and OGC have been introduced on the market. These sensors may, together with a Lambda sensor, provide efficient control for optimal performance with respect to emissions and efficiency. In this paper, results from an experimental parameter study in a modified commercial burner, followed by Chemkin simulations with relevant input data and experiments in a laboratory reactor and in a prototype burner, are summarised. Critical parameters for minimisation of NO x emission from pellet burners are investigated in some detail. Also, results from tests of a new sensor for unburnt are reported. In conclusion, relatively simple design modifications can significantly decrease NO x emission from today's pellet burners

  13. Multiverse data-flow control.

    Science.gov (United States)

    Schindler, Benjamin; Waser, Jürgen; Ribičić, Hrvoje; Fuchs, Raphael; Peikert, Ronald

    2013-06-01

    In this paper, we present a data-flow system which supports comparative analysis of time-dependent data and interactive simulation steering. The system creates data on-the-fly to allow for the exploration of different parameters and the investigation of multiple scenarios. Existing data-flow architectures provide no generic approach to handle modules that perform complex temporal processing such as particle tracing or statistical analysis over time. Moreover, there is no solution to create and manage module data, which is associated with alternative scenarios. Our solution is based on generic data-flow algorithms to automate this process, enabling elaborate data-flow procedures, such as simulation, temporal integration or data aggregation over many time steps in many worlds. To hide the complexity from the user, we extend the World Lines interaction techniques to control the novel data-flow architecture. The concept of multiple, special-purpose cursors is introduced to let users intuitively navigate through time and alternative scenarios. Users specify only what they want to see, the decision which data are required is handled automatically. The concepts are explained by taking the example of the simulation and analysis of material transport in levee-breach scenarios. To strengthen the general applicability, we demonstrate the investigation of vortices in an offline-simulated dam-break data set.

  14. Liquid-Flow Controller With Trickle Preflow

    Science.gov (United States)

    Cox, George B., Jr.

    1990-01-01

    Liquid-flow controller allows pressure in liquid to increase steeply with flow as flow starts, then provides more-gradual nearly linear rise of pressure with flow as flow and pressure increase beyond preset breakpoint. Controller alternative version of mechanism described in "Liquid-Flow Controller Responds To Pressure" (MFS-28329) and "Liquid-Flow Controller With Preset Break Pressure" (MFS-28330). Material cut out of cone at tip of pintle. Liquid always passes from shell, albeit at low rate. When pressure in shell great enough to force orifice away from pintle, liquid flows at greater rate.

  15. Bypass flow rate control method

    International Nuclear Information System (INIS)

    Kiyama, Yoichi.

    1997-01-01

    In a PWR type reactor, bypass flow rate is controlled by exchanging existent jetting hole plugs of a plurality of nozzles disposed to the upper end of incore structures in order to flow a portion of primary coolants as a bypass flow to the upper portion of the pressure vessel. Two kinds of exchange plugs, namely, a first plug and a second plug each having a jetting out hole of different diameter are used as exchange plugs. The first plug has the diameter as that of an existent plug and the second plug has a jetting out hole having larger diameter than that of the existent plug. Remained extent plugs are exchanged to a combination of the first and the second plugs without exchanging existent plugs having seizing with the nozzles, in which the number and the diameter of the jetting out holes of the second plugs are previously determined based on predetermined total bypass flow rate to be jetted from the entire plugs after exchange of plugs. (N.H.)

  16. Low NO{sub x}/SO{sub x} Burner retrofit for utility cyclone boilers. Public design report

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This Public Design Report provides available nonproprietary design information on the Low NO{sub x}SO{sub x} Burner Retrofit of Utility Cyclone Boilers project. In addition to the design aspects, the history of the project, the organization of the project, and the role of the funding parties are discussed. An overview of the Low NO{sub x}SO{sub x} (LNS) Burner, the cyclone boiler and the Southern Illinois Power Cooperative host site is presented. A detailed nonproprietary description of the individual process steps, plant systems, and resulting performance then follows. Narrative process descriptions, simplified process flow diagrams, input/output stream data, operating conditions and requirements are given for each unit. The plant demonstration program and start up provisions, the environmental considerations and control, monitoring and safety factors that are considered are also addressed.

  17. Bio-mimetic Flow Control

    Science.gov (United States)

    Choi, Haecheon

    2009-11-01

    Bio-mimetic engineering or bio-mimetics is the application of biological methods and systems found in nature to the study and design of engineering systems and modern technology (from Wikipedia). The concept itself is old, but successful developments have been made recently, especially in the research field of flow control. The objective of flow control based on the bio-mimetic approach is to develop novel concepts for reducing drag, increasing lift and enhancing aerodynamic performance. For skin friction reduction, a few ideas have been suggested such as the riblet from shark, compliant surface from dolphin, microbubble injection and multiple front-body curvature from penguin, and V-shaped protrusion from sailfish. For form drag reduction, several new attempts have been also made recently. Examples include the V-shaped spanwise grooves from saguaro cactus, overall shape of box fish, longitudinal grooves on scallop shell, bill of swordfish, hooked comb on owl wing, trailing-edge protrusion on dragonfly wing, and fillet. For the enhancement of aerodynamic performance, focuses have been made on the birds, fish and insects: e.g., double layered feather of landing bird, leading-edge serration of humpback-whale flipper, pectoral fin of flying fish, long tail on swallowtail-butterfly wing, wing flapping motion of dragonfly, and alula in birds. Living animals adapt their bodies to better performance in multi purposes, but engineering requires single purpose in most cases. Therefore, bio-mimetic approaches often produce excellent results more than expected. However, they are sometimes based on people's wrong understanding of nature and produce unwanted results. Successes and failures from bio-mimetic approaches in flow control will be discussed in the presentation.

  18. Regulator of Dust and Coal Burner of Power Boilers

    Directory of Open Access Journals (Sweden)

    W. Wujcik

    2004-01-01

    Full Text Available The papers considers problems concerning introduction of neutron regulator into engineering practice. The regulator makes it possible to regulate CO, N0^ and O2 values with the purpose to optimize ejections into environment. The paper contains scheme of automation control of cyclone dust and coal burner with the help of a neutron regulator.

  19. Optimization of burners in oxygen-gas fired glass furnace

    NARCIS (Netherlands)

    Kersbergen, M.J. van; Beerkens, R.G.C.; Sarmiento-Darkin, W.; Kobayashi, H.

    2012-01-01

    The energy efficiency performance, production stability and emissions of oxygen-fired glass furnaces are influenced by the type of burner, burner nozzle sizes, burner positions, burner settings, oxygen-gas ratios and the fuel distribution among all the burners. These parameters have been optimized

  20. Experimental investigations and numerical simulations of methane cup-burner flame

    Directory of Open Access Journals (Sweden)

    Kubát P.

    2013-04-01

    Full Text Available Pulsation frequency of the cup-burner flame was determined by means of experimental investigations and numerical simulations. Simplified chemical kinetics was successfully implemented into a laminar fluid flow model applied to the complex burner geometry. Our methodical approach is based on the monitoring of flame emission, fast Fourier transformation and reproduction of measured spectral features by numerical simulations. Qualitative agreement between experimental and predicted oscillatory behaviour was obtained by employing a two-step methane oxidation scheme.

  1. Characterization of a Rijke Burner as a Tool for Studying Distribute Aluminum Combustion

    OpenAIRE

    Newbold, Brian R.

    1996-01-01

    As prelude to the quantitative study of aluminum distributed combustion, the current work has characterized the acoustic growth, frequency, and temperature of a Rijke burner as a function of mass flow rate, gas composition, and geometry. By varying the exhaust temperature profile, the acoustic growth rate can be as much as tripled from the baseline value of approximately 120 s-1• At baseline, the burner operated in the third harmonic mode at a frequency of 1300 Hz, but geometry or temperature...

  2. Southern Woods-Burners: A Descriptive Analysis

    Science.gov (United States)

    M.L. Doolittle; M.L. Lightsey

    1979-01-01

    About 40 percent of the South's nearly 60,000 wildfires yearly are set by woods-burners. A survey of 14 problem areas in four southern States found three distinct sets of woods-burners. Most active woods-burners are young, white males whose activities are supported by their peers. An older but less active group have probably retired from active participation but...

  3. Parametric Study of High-Efficiency and Low-Emission Gas Burners

    Directory of Open Access Journals (Sweden)

    Shuhn-Shyurng Hou

    2013-01-01

    Full Text Available The objective of this study is to investigate the influence of three significant parameters, namely, swirl flow, loading height, and semi-confined combustion flame, on thermal efficiency and CO emissions of a swirl flow gas burner. We focus particularly on the effects of swirl angle and inclination angle on the performance of the swirl flow burner. The results showed that the swirl flow burner yields higher thermal efficiency and emits lower CO concentration than those of the conventional radial flow burner. A greater swirl angle results in higher thermal efficiency and CO emission. With increasing loading height, the thermal efficiency increases but the CO emission decreases. For a lower loading height (2 or 3 cm, the highest efficiency occurs at the inclination angle 15°. On the other hand, at a higher loading height, 4 cm, thermal efficiency increases with the inclination angle. Moreover, the addition of a shield can achieve a great increase in thermal efficiency, about 4-5%, and a decrease in CO emissions for the same burner (swirl flow or radial flow.

  4. Controlled pilot oxidizer for a gas turbine combustor

    Science.gov (United States)

    Laster, Walter R.; Bandaru, Ramarao V.

    2010-07-13

    A combustor (22) for a gas turbine (10) includes a main burner oxidizer flow path (34) delivering a first portion (32) of an oxidizer flow (e.g., 16) to a main burner (28) of the combustor and a pilot oxidizer flow path (38) delivering a second portion (36) of the oxidizer flow to a pilot (30) of the combustor. The combustor also includes a flow controller (42) disposed in the pilot oxidizer flow path for controlling an amount of the second portion delivered to the pilot.

  5. The Control of Junction Flows

    National Research Council Canada - National Science Library

    Smith, Charles

    1997-01-01

    An experimental study of the effects of spatially-limited (i.e. localized) surface suction on unsteady laminar and turbulent junction flows was performed using hydrogen bubble flow visualization and Particle Image Velocimetry (PIV...

  6. Electromagnetic application device for flow rate/flow speed control

    International Nuclear Information System (INIS)

    Yoshioka, Senji.

    1994-01-01

    Electric current and magnetic field are at first generated in a direction perpendicular to a flow channel of a fluid, and forces generated by electromagnetic interaction of the current and the magnetic field are combined and exerted on the fluid, to control the flow rate and the flow speed thereby decreasing flowing pressure loss. In addition, an electric current generation means and a magnetic field generation means integrated together are disposed to a structural component constituting the flow channel, and they are combined to attain the aimed effect. The current generating means forms a potential difference by supplying electric power to a pair of electrodes as a cathode and an anode by using structures disposed along the channel, to generate an electric field or electric current in a direction perpendicular to the flow channel. The magnetic field generating means forms a counter current (reciprocal current) by using structures disposed along the flow channel, to generate synthesized or emphasized magnetic field. The fluid can be applied with a force in the direction of the flowing direction by the electromagnetic interaction of the electric current and the magnetic field, thereby capable of propelling the fluid. Accordingly, the flowrate/flowing speed can be controlled inside of the flow channel and flowing pressure loss can be decreased. (N.H.)

  7. The Impact of Variable Inlet Mixture Stratification on Flame Topology and Emissions Performance of a Premixer/Swirl Burner Configuration

    Directory of Open Access Journals (Sweden)

    P. Koutmos

    2012-01-01

    Full Text Available The work presents the assessment of a low emissions premixer/swirl burner configuration utilizing lean stratified fuel preparation. An axisymmetric, single- or double-cavity premixer, formed along one, two, or three concentric disks promotes propane-air premixing and supplies the combustion zone at the afterbody disk recirculation with a radial equivalence ratio gradient. The burner assemblies are operated with a swirl co-flow to study the interaction of the recirculating stratified flame with the surrounding swirl. A number of lean and ultra-lean flames operated either with a plane disk stabilizer or with one or two premixing cavity arrangements were evaluated over a range of inlet mixture conditions. The influence of the variation of the imposed swirl was studied for constant fuel injections. Measurements of turbulent velocities, temperatures, OH* chemiluminescence and gas analysis provided information on the performance of each burner set up. Comparisons with Large Eddy Simulations, performed with an 11-step global chemistry, illustrated the flame front interaction with the vortex formation region under the influence of the variable inlet mixture stratifications. The combined effort contributed to the identification of optimum configurations in terms of fuel consumption and pollutants emissions and to the delineation of important controlling parameters and limiting fuel-air mixing conditions.

  8. Burner for a wood burning furnace

    Energy Technology Data Exchange (ETDEWEB)

    Nolting, H

    1981-12-10

    The burner according to the invention consists of a horizontal tube, whose front wall is penetrated by an intake pipe, which is surrounded by a pipe duct and several divided shells, which are arranged below the pipe duct. The front wall is also provided with air openings. The intake pipe is provided with a spiral and moves chopped wood into the burner.

  9. Premixed combustion on ceramic foam burners

    NARCIS (Netherlands)

    Bouma, P.H.; Goey, de L.P.H.

    1999-01-01

    Combustion of a lean premixed methane–air mixture stabilized on a ceramic foam burner has been studied. The stabilization of the flame in the radiant mode has been simulated using a one-dimensional numerical model for a burner stabilized flat-flame, taking into account the heat transfer between the

  10. Power flow control using quadrature boosters

    Science.gov (United States)

    Sadanandan, Sandeep N.

    A power system that can be controlled within security constraints would be an advantage to power planners and real-time operators. Controlling flows can lessen reliability issues such as thermal limit violations, power stability problems, and/or voltage stability conditions. Control of flows can also mitigate market issues by reducing congestion on some lines and rerouting power to less loaded lines or onto preferable paths. In the traditional control of power flows, phase shifters are often used. More advanced methods include using Flexible AC Transmission System (FACTS) Controllers. Some examples include Thyristor Controlled Series Capacitors, Synchronous Series Static Compensators, and Unified Power Flow Controllers. Quadrature Boosters (QBs) have similar structures to phase-shifters, but allow for higher voltage magnitude during real power flow control. In comparison with other FACTS controllers QBs are not as complex and not as expensive. The present study proposes to use QBs to control power flows on a power system. With the inclusion of QBs, real power flows can be controlled to desired scheduled values. In this thesis, the linearized power flow equations used for power flow analysis were modified for the control problem. This included modifying the Jacobian matrix, the power error vector, and calculating the voltage injected by the quadrature booster for the scheduled real power flow. Two scenarios were examined using the proposed power flow control method. First, the power flow in a line in a 5-bus system was modified with a QB using the method developed in this thesis. Simulation was carried out using Matlab. Second, the method was applied to a 30-bus system and then to a 118-bus system using several QBs. In all the cases, the calculated values of the QB voltages led to desired power flows in the designated line.

  11. Flow control for oblique shock wave reflections

    OpenAIRE

    Giepman, R.H.M.

    2016-01-01

    Shock wave-boundary layer interactions are prevalent in many aerospace applications that involve transonic or supersonic flows. Such interactions may lead to boundary layer separation, flow unsteadiness and substantial losses in the total pressure. Flow control techniques can help to mitigate these adverse effects and stabilize the interaction. This thesis focuses on passive flow control techniques for oblique shock wave reflections on flat plates and presents experimental results for both la...

  12. A new scaling methodology for NO(x) emissions performance of gas burners and furnaces

    Science.gov (United States)

    Hsieh, Tse-Chih

    1997-11-01

    A general burner and furnace scaling methodology is presented, together with the resulting scaling model for NOsb{x} emissions performance of a broad class of swirl-stabilized industrial gas burners. The model is based on results from a set of novel burner scaling experiments on a generic gas burner and furnace design at five different scales having near-uniform geometric, aerodynamic, and thermal similarity and uniform measurement protocols. These provide the first NOsb{x} scaling data over the range of thermal scales from 30 kW to 12 MW, including input-output measurements as well as detailed in-flame measurements of NO, NOsb{x}, CO, Osb2, unburned hydrocarbons, temperature, and velocities at each scale. The in-flame measurements allow identification of key sources of NOsb{x} production. The underlying physics of these NOsb{x} sources lead to scaling laws for their respective contributions to the overall NOsb{x} emissions performance. It is found that the relative importance of each source depends on the burner scale and operating conditions. Simple furnace residence time scaling is shown to be largely irrelevant, with NOsb{x} emissions instead being largely controlled by scaling of the near-burner region. The scalings for these NOsb{x} sources are combined in a comprehensive scaling model for NOsb{x} emission performance. Results from the scaling model show good agreement with experimental data at all burner scales and over the entire range of turndown, staging, preheat, and excess air dilution, with correlations generally exceeding 90%. The scaling model permits design trade-off assessments for a broad class of burners and furnaces, and allows performance of full industrial scale burners and furnaces of this type to be inferred from results of small scale tests.

  13. Study and mathematical model of ultra-low gas burner

    International Nuclear Information System (INIS)

    Gueorguieva, A.

    2001-01-01

    The main objective of this project is prediction and reduction of NOx and CO 2 emissions under levels recommended from European standards for gas combustion processes. A mathematical model of burner and combustion chamber is developed based on interacting fluid dynamics processes: turbulent flow, gas phase chemical reactions, heat and radiation transfer The NOx prediction model for prompt and thermal NOx is developed. The validation of CFD (Computer fluid-dynamics) simulations corresponds to 5 MWI burner type - TEA, installed on CASPER boiler. This burner is three-stream air distribution burner with swirl effect, designed by ENEL to meet future NOx emission standards. For performing combustion computer modelling, FLUENT CFD code is preferred, because of its capabilities to provide accurately description of large number of rapid interacting processes: turbulent flow, phase chemical reactions and heat transfer and for its possibilities to present wide range of calculation and graphical output reporting data The computational tool used in this study is FLUENT version 5.4.1, installed on fs 8200 UNIX systems The work includes: study the effectiveness of low-NOx concepts and understand the impact of combustion and swirl air distribution and flue gas recirculation on peak flame temperatures, flame structure and fuel/air mixing. A finite rate combustion model: Eddy-Dissipation (Magnussen-Hjertager) Chemical Model for 1, 2 step Chemical reactions of bi-dimensional (2D) grid is developed along with NOx and CO 2 predictions. The experimental part of the project consists of participation at combustion tests on experimental facilities located in Livorno. The results of the experiments are used, to obtain better vision for combustion process on small-scaled design and to collect the necessary input data for further Fluent simulations

  14. A novel micromechanical flow controller

    NARCIS (Netherlands)

    van Toor, M.W.; van Toor, M.W.; Lammerink, Theodorus S.J.; Gardeniers, Johannes G.E.; Elwenspoek, Michael Curt; Monsma, D.J.

    A new concept for a micromechanical flow regulator is presented. Regulation of the flow is achieved using variation of channel length instead of channel diameter. Several design concepts together with their application in fluidic systems are presented. A regulator for biomedical use, as a part of a

  15. Flow control for oblique shock wave reflections

    NARCIS (Netherlands)

    Giepman, R.H.M.

    2016-01-01

    Shock wave-boundary layer interactions are prevalent in many aerospace applications that involve transonic or supersonic flows. Such interactions may lead to boundary layer separation, flow unsteadiness and substantial losses in the total pressure. Flow control techniques can help to mitigate these

  16. Development of stoker-burner wood chip combustion systems for the UK market

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    The document makes a case for the development of a design of wood chip stoker-burner more suited to the UK than those currently imported from Sweden and Finland. The differences would centre on market conditions, performance and cost-effectiveness and the devices would be manufactured or part-manufactured in the UK. Econergy Limited was contracted by the DTI as part of its Sustainable Energy Programmes to design and construct an operational prototype stoker-burner rated at 120 kWth. A test rig was built to: (i) study modified burner heads and (ii) develop control hardware and a control strategy. Both (i) and (ii) are described. Tests brought about an increase in performance of the burner head and its wet wood performance. It was considered that further improvements are achievable and six areas for future study were suggested.

  17. Combustion characteristics of porous media burners under various back pressures: An experimental study

    Directory of Open Access Journals (Sweden)

    Xuemei Zhang

    2017-07-01

    Full Text Available The porous media combustion technology is an effective solution to stable combustion and clean utilization of low heating value gas. For observing the combustion characteristics of porous media burners under various back pressures, investigating flame stability and figuring out the distribution laws of combustion gas flow and resistance loss, so as to achieve an optimized design and efficient operation of the devices, a bench of foamed ceramics porous media combustion devices was thus set up to test the cold-state resistance and hot-state combustion characteristic of burners in working conditions without back pressures and with two different back pressures. The following results are achieved from this experimental study. (1 The strong thermal reflux of porous media can preheat the premixed air effectively, so the flame can be kept stable easily, the combustion equivalent ratio of porous media burners is lower than that of traditional burners, and its pollutant content of flue gas is much lower than the national standard value. (2 The friction coefficient of foamed ceramics decreases with the increase of air flow rate, and its decreasing rate slows down gradually. (3 When the flow rate of air is low, viscosity is the dominant flow resistance, and the friction coefficient is in an inverse relation with the flow rate. (4 As the flow rate of air increases, inertia is the dominant flow resistance, and the friction coefficient is mainly influenced by the roughness and cracks of foamed ceramics. (5 After the introduction of secondary air, the minimum equivalent ratio of porous media burners gets much lower and its range of equivalent ratio is much larger than that of traditional burners.

  18. RF torch discharge combined with conventional burner

    International Nuclear Information System (INIS)

    Janca, J.; Tesar, C.

    1996-01-01

    The design of the combined flame-rf-plasma reactor and experimental examination of this reactor are presented. For the determination of the temperature in different parts of the combined burner plasma the methods of emission spectroscopy were used. The temperatures measured in the conventional burner reach the maximum temperature 1900 K but in the burner with the superimposed rf discharge the neutral gas temperature substantially increased up to 2600 K but also the plasma volume increases substantially. Consequently, the resident time of reactants in the reaction zone increases

  19. Modular Control Flow Analysis for Libraries

    DEFF Research Database (Denmark)

    Probst, Christian W.

    2002-01-01

    One problem in analyzing object oriented languages is that the exact control flow graph is not known statically due to dynamic dispatching. However, this is needed in order to apply the large class of known interprocedural analysis. Control Flow Analysis in the object oriented setting aims...

  20. Flow Control in a Compact Inlet

    Science.gov (United States)

    Vaccaro, John C.

    2011-12-01

    An experimental investigation of flow control, via various control jets actuators, was undertaken to eliminate separation and secondary flows in a compact inlet. The compact inlet studied was highly aggressive with a length-to-diameter ratio of 1.5. A brand new facility was designed and built to enable various actuation methodologies as well as multiple measurement techniques. Techniques included static surface pressure, total pressure, and stereoscopic particle image velocimetry. Experimental data were supplemented with numerical simulations courtesy of Prof. Kenneth Jansen, Dr. Onkar Sahni, and Yi Chen. The baseline flow field was found to be dominated by two massive separations and secondary flow structures. These secondary structures were present at the aerodynamic interface plane in the form of two counter-rotating vortices inducing upwash along centerline. A dominant shedding frequency of 350 Hz was measured both at the aerodynamic interface plane and along the lower surface of the inlet. Flow control experiments started utilizing a pair of control jets placed in streamwise locations where flow was found to separate. Tests were performed for a range of inlet Mach numbers from 0.2 to 0.44. Steady and unsteady static pressure measurements along the upper and lower walls of the duct were performed for various combinations of actuation. The parameters that were tested include the control jets momentum coefficient, their blowing ratio, the actuation frequency, as well as different combinations of jets. It was shown that using mass flux ratio as a criterion to define flow control is not sufficient, and one needs to provide both the momentum coefficient and the blowing ratio to quantify the flow control performance. A detailed study was undertaken on controlling the upstream separation point for an inlet Mach number of 0.44. Similar to the baseline flow field, the flow field associated with the activation of a two-dimensional control jet actuator was dominated by

  1. Microjet burners for molecular-beam sources and combustion studies

    Science.gov (United States)

    Groeger, Wolfgang; Fenn, John B.

    1988-09-01

    A novel microjet burner is described in which combustion is stabilized by a hot wall. The scale is so small that the entire burner flow can be passed through a nozzle only 0.2 mm or less in diameter into an evacuated chamber to form a supersonic free jet with expansion so rapid that all collisional processes in the jet gas are frozen in a microsecond or less. This burner can be used to provide high-temperature source gas for free jet expansion to produce intense beams of internally hot molecules. A more immediate use would seem to be in the analysis of combustion products and perhaps intermediates by various kinds of spectroscopies without some of the perturbation effects encountered in probe sampling of flames and other types of combustion devices. As an example of the latter application of this new tool, we present infrared emission spectra for jet gas obtained from the combustion of oxygen-hydrocarbon mixtures both fuel-rich and fuel-lean operation. In addition, we show results obtained by mass spectrometric analysis of the combustion products.

  2. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME II. SECOND GENERATION LOW-NOX BURNERS

    Science.gov (United States)

    The report describes tests to evaluate the performance characteristics of three Second Generation Low-NOx burner designs: the Dual Register burner (DRB), the Babcock-Hitachi NOx Reducing (HNR) burner, and the XCL burner. The three represent a progression in development based on t...

  3. Passive safety design characteristics of the KALIMER-600 burner reactor

    International Nuclear Information System (INIS)

    Kwon, Young-Min; Jeong, Hae-Yong; Cho, Chung-Ho; Ha, Ki-Seok; Kim, Sang-Ji

    2009-01-01

    The Korea Atomic Energy Research Institute (KAERI) has recently studied several burner core designs for a transuranics (TRU) transmutation based on the breakeven core geometry of KALIMER-600. The KALIMER-600 is a net electrical rating of 600MWe, sodium-cooled, metallic-fueled, pool-type reactor. For the burner core concept selected for the present analysis, the smearing fractions of the fuel rods in three fuel zones are changed while maintaining the cladding outer diameter and cladding thickness. The resulting fuel slug smearing fractions of the inner, middle, and outer core zones are 36%, 40%, and 48%, respectively. The TRU conversion ratio is 0.57 and the TRU enrichment of the driver fuel is set to 30.0 w/o because of the current practical limitation of the U-TRU-10%Zr metal fuel database. The purpose of this paper is to evaluate the safety performance characteristics provided by the passive safety design features in the KALIMER-600 burner reactor by using a system-wide safety analysis code. The present scoping analysis focuses on an assessment of the enhanced safety design features that provide passive and self-regulating responses to transient conditions and an evaluation of the safety margin during unprotected overpower, unprotected loss of flow, and unprotected loss of heat sink events. The analysis results show that the KALIMER-600 burner reactor provides larger safety margins with respect to the sodium boiling, fuel rod integrity, and structural integrity. The overall inherent safety can be enhanced by accounting for the reactivity feedback mechanisms in the design process. (author)

  4. Integrated soft sensor model for flow control.

    Science.gov (United States)

    Aijälä, G; Lumley, D

    2006-01-01

    Tighter discharge permits often require wastewater treatment plants to maximize utilization of available facilities in order to cost-effectively reach these goals. Important aspects are minimizing internal disturbances and using available information in a smart way to improve plant performance. In this study, flow control throughout a large highly automated wastewater treatment plant (WWTP) was implemented in order to reduce internal disturbances and to provide a firm foundation for more advanced process control. A modular flow control system was constructed based on existing instrumentation and soft sensor flow models. Modules were constructed for every unit process in water treatment and integrated into a plant-wide model. The flow control system is used to automatically control recirculation flows and bypass flows at the plant. The system was also successful in making accurate flow estimations at points in the plant where it is not possible to have conventional flow meter instrumentation. The system provides fault detection for physical flow measuring devices. The module construction allows easy adaptation for new unit processes added to the treatment plant.

  5. Image-based spectroscopic sensor for the automatic control gas burners in the glass-processing industry. Multichannel spectral detection of flame emissions and multivariate analysis methods allow for optical quality monitoring and control of industrial burners; Bildgebende optische Spektralsensorik zur automatischen Regelung von Gasbrennern fuer die Glas verarbeitende Industrie. Durch mehrkanalige spektrale Aufnahmen der Flammenemission und multivariate Auswertemethoden kann die Qualitaet der Gasversorgung bei industriellen Brennern optisch ueberwacht und geregelt werden

    Energy Technology Data Exchange (ETDEWEB)

    Knetsch, R.; Arnold, W. [Herbert Arnold GmbH und Co. KG, Weilburg (Germany); Erfurth, F.; Scheibe, A.; Nyuyki, B.; Schmidt, W.D. [GMBU e.V., Jena (Germany). Fachsektion Photonik und Sensorik

    2009-07-01

    The precise composition of the combustion gas mixture of burners is essential for the maximum achievable flame temperature as well as for the economic use of raw material. We present a mobile device for optical flame analysis and optimization of gas supply for industrial burners. The relative fuel-oxygen-ratio can be assessed by means of spectral emission in the visible and UV region by factoring in the distribution of gas emissions along the flame. Based on spectral imaging technology our sensor allows for calculation of a flame index stating the quality of fuel supply. A laboratory sample of the flame sensor has been tested with different burners using natural gas and propane. The flame index has been determined successful for several fuel-oxygen-ratios. Practical experiments showed that uncomplicated software-based adaptation of the device to several burner configurations is possible.

  6. Flow Control of Flexible Structures

    Science.gov (United States)

    2017-09-06

    levels of modeling [Dowell and Hall, 2001]. Fur- thermore, even for the most complex models, the main research goal has been a mathe - matical description...possibility for localized, discrete actuation to coun- teract detrimental flow developments before they result in significant structural loads and

  7. A design of steady state fusion burner

    International Nuclear Information System (INIS)

    Hasegawa, Akira; Hatori, Tadatsugu; Itoh, Kimitaka; Ikuta, Takashi; Kodama, Yuji.

    1975-01-01

    We present a brief design of a steady state fusion burner in which a continuous burning of nuclear fuel may be achieved with output power of a gigawatt. The laser fusion is proposed to ignite the fuel. (auth.)

  8. Efficiency improvements of electromagnetic flow control

    International Nuclear Information System (INIS)

    Spong, E.; Reizes, J.A.; Leonardi, E.

    2005-01-01

    In turbulent flow, frictional resistance and heat transfer are controlled to a large degree by the intensity of the turbulence fluctuations in the near vicinity of a surface. In the case of a weak electrically conducting fluid, such as seawater, turbulence intensity can be controlled by subjecting the fluid to electromagnetic fields. This technique, known as Electro-magneto-hydro-dynamic (EMHD) flow control, has been shown to have promise as a means of reducing the turbulence intensity, and hence heat transfer or frictional drag of turbulent boundary layers. Unfortunately EMHD flow control currently suffers from poor efficiency due to the high energy requirements of the electromagnetic field. A numerical study has been conducted in which a new electromagnetic actuator design has been developed to provide a more efficient spatial distribution of the electromagnetic forces. The new actuator design has then been coupled to an ideal flow sensor. A flow control subroutine, embedded in the numerical model, uses the velocity information from the ideal sensor to determine the appropriate actuating force to apply to the flow at each time step. The new actuator design has been shown to be capable of successfully attenuating a sequence of artificial low speed streaks in a simplified model of a low Reynolds number turbulent boundary layer. Thus, a potential solution to the poor efficiency of EMHD flow control has been offered by providing the means whereby the expensive electromagnetic forces can be strategically and sparingly applied to the flow

  9. Manipulation of vortex rings for flow control

    International Nuclear Information System (INIS)

    Toyoda, Kuniaki; Hiramoto, Riho

    2009-01-01

    This paper reviews the dynamics of vortex rings and the control of flow by the manipulation of vortex rings. Vortex rings play key roles in many flows; hence, the understanding of the dynamics of vortex rings is crucial for scientists and engineers dealing with flow phenomena. We describe the structures and motions of vortex rings in circular and noncircular jets, which are typical examples of flows evolving into vortex rings. For circular jets the mechanism of evolving, merging and breakdown of vortex rings is described, and for noncircular jets the dynamics of three-dimensional deformation and interaction of noncircular vortex rings under the effect of self- and mutual induction is discussed. The application of vortex-ring manipulation to the control of various flows is reviewed with successful examples, based on the relationship between the vortex ring dynamics and the flow properties. (invited paper)

  10. Burners and combustion apparatus for carbon nanomaterial production

    Science.gov (United States)

    Alford, J. Michael; Diener, Michael D; Nabity, James; Karpuk, Michael

    2013-02-05

    The invention provides improved burners, combustion apparatus, and methods for carbon nanomaterial production. The burners of the invention provide sooting flames of fuel and oxidizing gases. The condensable products of combustion produced by the burners of this invention produce carbon nanomaterials including without limitation, soot, fullerenic soot, and fullerenes. The burners of the invention do not require premixing of the fuel and oxidizing gases and are suitable for use with low vapor pressure fuels such as those containing substantial amounts of polyaromatic hydrocarbons. The burners of the invention can operate with a hot (e.g., uncooled) burner surface and require little, if any, cooling or other forms of heat sinking. The burners of the invention comprise one or more refractory elements forming the outlet of the burner at which a flame can be established. The burners of the invention provide for improved flame stability, can be employed with a wider range of fuel/oxidizer (e.g., air) ratios and a wider range of gas velocities, and are generally more efficient than burners using water-cooled metal burner plates. The burners of the invention can also be operated to reduce the formation of undesirable soot deposits on the burner and on surfaces downstream of the burner.

  11. Compressed-air flow control system.

    Science.gov (United States)

    Bong, Ki Wan; Chapin, Stephen C; Pregibon, Daniel C; Baah, David; Floyd-Smith, Tamara M; Doyle, Patrick S

    2011-02-21

    We present the construction and operation of a compressed-air driven flow system that can be used for a variety of microfluidic applications that require rapid dynamic response and precise control of multiple inlet streams. With the use of inexpensive and readily available parts, we describe how to assemble this versatile control system and further explore its utility in continuous- and pulsed-flow microfluidic procedures for the synthesis and analysis of microparticles.

  12. Development and demonstration of a gas-fired recuperative confined radiant burner (deliverable 42/43). Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-06-01

    The objective of the project was to develop and demonstrate an innovative, efficient, low-pollutant, recuperative gas-fired IR-system (infrared radiation) for industrial processes (hereafter referred to as the CONRAD-system). The CONRAD-system is confined, so flue gases from the combustion can be kept separated from the product. The gas/air mixture to the burner is preheated by means of the flue gas, which increases the radiant efficiency of the CONRAD-system significantly over traditional gas-fired IR burners. During the first phase of the project, the CONRAD-system was designed and developed. The conducted work included a survey on suitable burner materials, modelling of the burner system, basic design of burner construction, control etc., experimental characterisation of several preprototypes and detailed design of the internal heat exchanger in the burner. The result is a cost effective burner system with a documented radiant efficiency up to 66% and low emissions (NO{sub x} and CO) all in accordance with the criteria of success set up at the start of the project. In the second phase of the project, the burner system was established and tested in laboratory and in four selected industrial applications: 1) Drying of coatings on sand cores in the automotive industry. 2) Baking of bread/cake. 3) General purpose painting/powder curing process 4. Curing of powder paint on wood components. The results from the preliminary tests Overe used to optimise the CONRAD-system, before it was applied in the industrial processes and demonstrated. However, the optimised burners manufactured for demonstration suffered from different 'infant failures', which made the installation in an industrial environment very cumbersome, and even impossible in the food industry and the automotive industry. In the latter cases realistic laboratory tests Overe carried out and the established know how reported for use when the burner problems are overcome.(au)

  13. The art and science of flow control

    Science.gov (United States)

    Gad-El-hak, Mohamed

    1989-01-01

    The ability to actively or passively manipulate a flow field to effect a desired change is of immense technological importance. In this article, methods of control to achieve transition delay, separation postponement, lift enhancement, drag reduction, turbulence augmentation, or noise suppression are considered. Emphasis is placed on external boundary-layer flows although applicability of some of the methods reviewed for internal flows will be mentioned. Attempts will be made to present a unified view of the different methods of control to achieve a variety of end results. Performance penalties associated with a particular method such as cost, complexity, or trade-off will be elaborated.

  14. A Lyapunov theory based UPFC controller for power flow control

    Energy Technology Data Exchange (ETDEWEB)

    Zangeneh, Ali; Kazemi, Ahad; Hajatipour, Majid; Jadid, Shahram [Center of Excellence for Power Systems Automation and Operation, Iran University of Science and Technology, Tehran (Iran)

    2009-09-15

    Unified power flow controller (UPFC) is the most comprehensive multivariable device among the FACTS controllers. Capability of power flow control is the most important responsibility of UPFC. According to high importance of power flow control in transmission lines, the proper controller should be robust against uncertainty and disturbance and also have suitable settling time. For this purpose, a new controller is designed based on the Lyapunov theory and its stability is also evaluated. The Main goal of this paper is to design a controller which enables a power system to track reference signals precisely and to be robust in the presence of uncertainty of system parameters and disturbances. The performance of the proposed controller is simulated on a two bus test system and compared with a conventional PI controller. The simulation results show the power and accuracy of the proposed controller. (author)

  15. Monitoring And Controlling Hydroponic Flow

    Science.gov (United States)

    Dreschel, Thomas W.

    1992-01-01

    Pressure-monitoring and -controlling apparatus maintains slight suction required on nutrient solution in apparatus described in "Tubular Membrane Plant-Growth Unit" (KSC-11375), while overcoming gravity effects on operation of system on Earth. Suction helps to hold solution in tubular membrane.

  16. Characteristics of premixed flames stabilized in an axisymmetric curved-wall jet burner with tip modification

    KAUST Repository

    Kim, Daejoong; Gil, Y. S.; Chung, TaeWon; Chung, Suk-Ho

    2009-01-01

    The stabilization characteristics of premixed flames in an axisymmetric curved-wall jet burner have been experimentally investigated. This burner utilized the Coanda effect on top of a burner tip. The initially spherical burner tip was modified to a

  17. Correction of edge-flame propagation speed in a counterflow, annular slot burner

    KAUST Repository

    Tran, Vu Manh

    2015-10-22

    To characterize the propagation modes of flames, flame propagation speed must be accurately calculated. The impact of propagating edge-flames on the flow fields of unburned gases is limited experimentally. Thus, few studies have evaluated true propagation speeds by subtracting the flow velocities of unburned gases from flame displacement speeds. Here, we present a counterflow, annular slot burner that provides an ideal one-dimensional strain rate and lengthwise zero flow velocity that allowed us to study the fundamental behaviors of edge-flames. In addition, our burner has easy optical access for detailed laser diagnostics. Flame displacement speeds were measured using a high-speed camera and related flow fields of unburned gases were visualized by particle image velocimetry. These techniques allowed us to identify significant modifications to the flow fields of unburned gases caused by thermal expansion of the propagating edges, which enabled us to calculate true flame propagation speeds that took into account the flow velocities of unburned gases.

  18. Recycle flow rate control device

    International Nuclear Information System (INIS)

    Sumida, Susumu; Mizuno, Hiroshi; Oka, Yoko.

    1984-01-01

    Purpose: To attain stable low hydraulic power operation with no abnormal changes in the reactor water level by smoothly varying the speed control for the recycling pump for regulating the reactor core flowrate in BWR type reactors. Constitution: In a recycling control system equipped with an internal pump having a response characteristic higher by ten and several times or more than that of prior pump, a previously programed recycling run-back signal is inputted to a speed regulator upon load interruption of the electric generator to thereby control the operation of the internal pump driving motor such that the speed is decreased rapidly at the initial state and smoothly thereafter. The run-back singal is passed through a primary delay circuit so that the interruption of the motor operation does not directly performed by the signal interruption upon failure. As the result, the amount of void produced is also made smooth and the reactor water level varies smoothly as well, whereby the reactor power can be reduced with a sufficient margin. (Kamimura, M.)

  19. Thermionic cogeneration burner assessment study. Third quarterly technical progress report, April-June, 1983

    Energy Technology Data Exchange (ETDEWEB)

    1983-01-01

    The specific tasks of this study are to mathematically model the thermionic cogeneration burner, experimentally confirm the projected energy flows in a thermal mock-up, make a cost estimate of the burner, including manufacturing, installation and maintenance, review industries in general and determine what groups of industries would be able to use the electrical power generated in the process, select one or more industries out of those for an in-depth study, including determination of the performance required for a thermionic cogeneration system to be competitive in that industry. Progress is reported. (WHK)

  20. Correction of edge-flame propagation speed in a counterflow, annular slot burner

    KAUST Repository

    Tran, Vu Manh; Cha, Min

    2015-01-01

    to study the fundamental behaviors of edge-flames. In addition, our burner has easy optical access for detailed laser diagnostics. Flame displacement speeds were measured using a high-speed camera and related flow fields of unburned gases were visualized

  1. Experimental and numerical investigation of the acoustic response of multi-slit Bunsen burners

    NARCIS (Netherlands)

    Kornilov, V.N.; Rook, R.; Thije Boonkkamp, ten J.H.M.; Goey, de L.P.H.

    2009-01-01

    Experimental and numerical techniques to characterize the response of premixed methane-air flames to acoustic waves are discussed and applied to a multi-slit Bunsen burner. The steady flame shape, flame front kinematics and flow field of acoustically exited flames, as well as the flame transfer

  2. Modelling and control of systems with flow

    NARCIS (Netherlands)

    van Mourik, S.

    2008-01-01

    In practice, feedback control design consists of three steps: modelling, model reduction and controller design for the reduced model. Systems with flow are often complicated, and there is yet no standard algorithm that integrates these steps. In this thesis we make a modest effort by considering two

  3. Effect of fuel volatility on performance of tail-pipe burner

    Science.gov (United States)

    Barson, Zelmar; Sargent, Arthur F , Jr

    1951-01-01

    Fuels having Reid vapor pressures of 6.3 and 1.0 pounds per square inch were investigated in a tail-pipe burner on an axial-flow-type turbojet engine at a simulated flight Mach number of 0.6 and altitudes from 20,000 to 45,000 feet. With the burner configuration used in this investigation, having a mixing length of only 8 inches between the fuel manifold and the flame holder, the low-vapor-pressure fuel gave lower combustion efficiency at a given tail-pipe fuel-air ratio. Because the exhaust-nozzle area was fixed, the lower efficiency resulted in lower thrust and higher specific fuel consumption. The maximum altitude at which the burner would operate was practically unaffected by the change in fuel volatility.

  4. Numerical study of MHD supersonic flow control

    Science.gov (United States)

    Ryakhovskiy, A. I.; Schmidt, A. A.

    2017-11-01

    Supersonic MHD flow around a blunted body with a constant external magnetic field has been simulated for a number of geometries as well as a range of the flow parameters. Solvers based on Balbas-Tadmor MHD schemes and HLLC-Roe Godunov-type method have been developed within the OpenFOAM framework. The stability of the solution varies depending on the intensity of magnetic interaction The obtained solutions show the potential of MHD flow control and provide insights into for the development of the flow control system. The analysis of the results proves the applicability of numerical schemes, that are being used in the solvers. A number of ways to improve both the mathematical model of the process and the developed solvers are proposed.

  5. Engineering models for low-NO{sub x} burners

    Energy Technology Data Exchange (ETDEWEB)

    Storm Pedersen, Lars

    1997-08-01

    The present Ph.D. thesis describes a theoretical investigation of NO formation in pulverised coal combustion and an experimental investigation of co-combustion of straw and pulverised coal. The theoretical work has resulted in a simplified mathematical model of a swirling pulverised coal flame able to predict the NO emission and the burnout of coal. In order to simplify the flow pattern of a confined swirling flame, the residence time distribution (RTD) in a swirling pulverised coal flame was determined. This was done by using the solution of a detailed fluid dynamic mathematical model for a 2.2 MW{sub th} and a 12 MW{sub th} pulverised coal flame. From the mathematical solution the RTD was simulated by tracing a number of fluid particles or inert particles. The RTD in the near burner zone was investigated by use of the mathematical model for the 2.2 MW{sub th} and 12 MW{sub th} flame. Results showed that the gas phase in the near burner zone may be approximated as a CSTR and that the mean residence time increased with particle size. In pulverised coal flames, the most important volatile nitrogen component forming NO{sub x} is HCN. To be able to model the nitrogen chemistry in coal flames it is necessary to have an adequate model for HCN oxidation. In order to develop a model for HCN/NH{sub 3}/NO conversion, a systematic reduction of a detailed chemical kinetic model was performed. Based on the simplification of the flow pattern for a swirling flame and the reduced chemistry developed, a chemical engineering model of pulverised coal flame was established. The objectives were to predict the NO emission, the CO emission, and the burnout of char. The effects of co-firing straw and pulverised coal was investigated in a 2.5 MW{sub th} pilot-scale burner and a 250 MW{sub e} utility boiler. In the 2.5 MW{sub th} trial the straw was chopped and fed separately to the burner, whereas in the full-scale experiment the straw was pre-processed as pellets and pulverised with the

  6. Fully Premixed Low Emission, High Pressure Multi-Fuel Burner

    Science.gov (United States)

    Nguyen, Quang-Viet (Inventor)

    2012-01-01

    A low-emissions high-pressure multi-fuel burner includes a fuel inlet, for receiving a fuel, an oxidizer inlet, for receiving an oxidizer gas, an injector plate, having a plurality of nozzles that are aligned with premix face of the injector plate, the plurality of nozzles in communication with the fuel and oxidizer inlets and each nozzle providing flow for one of the fuel and the oxidizer gas and an impingement-cooled face, parallel to the premix face of the injector plate and forming a micro-premix chamber between the impingement-cooled face and the in injector face. The fuel and the oxidizer gas are mixed in the micro-premix chamber through impingement-enhanced mixing of flows of the fuel and the oxidizer gas. The burner can be used for low-emissions fuel-lean fully-premixed, or fuel-rich fully-premixed hydrogen-air combustion, or for combustion with other gases such as methane or other hydrocarbons, or even liquid fuels.

  7. Wood pellets for stoker burner

    International Nuclear Information System (INIS)

    Nykaenen, S.

    2000-01-01

    The author of this article has had a stoker for several years. Wood chips and sod peat has been used as fuels in the stoker, either separately or mixed. Last winter there occurred problems with the sod peat due to poor quality. Wood pellets, delivered by Vapo Oy were tested in the stoker. The price of the pellets seemed to be a little high 400 FIM/500 kg large sack. If the sack is returned in good condition 50 FIM deposit will be repaid to the customer. However, Vapo Oy informed that the calorific value of wood pellets is three times higher than that of sod peat so it should not be more expensive than sod peat. When testing the wood pellets in the stoker, the silo of the stoker was filled with wood pellets. The adjustments were first left to position used for sod peat. However, after the fire had ignited well, the adjustments had to be decreased. The content of the silo was combusted totally. The combustion of the content of the 400 litter silo took 4 days and 22 hours. Respectively combustion of 400 l silo of good quality sod peat took 2 days. The water temperature with wood pellets remained at 80 deg C, while with sod peat it dropped to 70 deg C. The main disadvantage of peat with small loads is the unhomogenous composition of the peat. The results of this test showed that wood pellets will give better efficiency than peat, especially when using small burner heads. The utilization of them is easier, and the amount of ash formed in combustion is significantly smaller than with peat. Wood pellets are always homogenous and dry if you do not spoil it with unproper storage. Pellets do not require large storages, the storage volume needed being less than a half of the volume needed for sod peat. When using large sacks the amount needed can even be transported at the trunk of a passenger car. Depending on the area to be heated, a large sack is sufficient for heating for 2-3 weeks. Filling of stoker every 2-5 day is not an enormous task

  8. Methane combustion in catalytic premixed burners

    International Nuclear Information System (INIS)

    Cerri, I.; Saracco, G.; Specchia, V.

    1999-01-01

    Catalytic premixed burners for domestic boiler applications were developed with the aim of achieving a power modularity from 10 to 100% and pollutant emissions limited to NO x 2 , where the combustion took place entirely inside the burner heating it to incandescence and allowing a decrease in the flame temperature and NO x emissions. Such results were confirmed through further tests carried out in a commercial industrial-scale boiler equipped with the conical panels. All the results, by varying the excess air and the heat power employed, are presented and discussed [it

  9. The new low-NO{sub x} burner

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Masato [Joban Joint Power Corporation, Ltd., Nagasaki (Japan); Domoto, Kazuhiro; Tanaka, Ryuichiro [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan). Boiler Engineering Dept. Power Systems; Matsumoto, Keigo [Mitsubishi Heavy Industries, Ltd., Nagasaki (Japan). Combustion Lab.

    2013-11-01

    Burner design requires good ignitability, high burn-up rate and low NO{sub x} emissions. Mitsubishi Heavy Industries Ltd. (MHI) developed a low-NO{sub x} burner which meets the aforementioned requirements. It also needs less combustion air, the burner nozzle is subjected to less thermal stresses, and the potential of NO{sub x} corrosion is being reduced. (orig.)

  10. DESIGN REPORT: LOW-NOX BURNERS FOR PACKAGE BOILERS

    Science.gov (United States)

    The report describes a low-NOx burner design, presented for residual-oil-fired industrial boilers and boilers cofiring conventional fuels and nitrated hazardous wastes. The burner offers lower NOx emission levels for these applications than conventional commercial burners. The bu...

  11. EVALUATION OF INTERNALLY STAGED COAL BURNERS AND SORBENT JET AERODYNAMICS FOR COMBINED SO2/NOX CONTROL IN UTILITY BOILERS, VOLUME 1, TESTING IN A 10 MILLION BTU/HR EXPERIMENTAL FURNACE

    Science.gov (United States)

    The document gives results of tests conducted in a 2 MWt experimental furnace to: (1) investigate ways to reduce NOx emissions from utility coal burners without external air ports (i.e., with internal fuel/air staging); and (2) improve the performance of calcium-based sorbents fo...

  12. Locus of control in relation to flow

    Directory of Open Access Journals (Sweden)

    Celeste M Taylor

    2006-04-01

    Full Text Available The principal objective of the study was to examine the relationship between locus of control and optimal experience (flow in carrying out work and/or study activities. Two questionnaires measuring the aforementioned constructs were administered to a group of first and second-year Human Resource Management students (n=168 between the ages of 16 and 30. The results suggest that more frequent experience of flow is positively correlated with Autonomy and Internal Locus of Control. Limitations, lines of future research, implications and further contributions are discussed.

  13. Numerical simulations of a large scale oxy-coal burner

    Energy Technology Data Exchange (ETDEWEB)

    Chae, Taeyoung [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Park, Sanghyun; Ryu, Changkook [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Yang, Won [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group

    2013-07-01

    Oxy-coal combustion is one of promising carbon dioxide capture and storage (CCS) technologies that uses oxygen and recirculated CO{sub 2} as an oxidizer instead of air. Due to difference in physical properties between CO{sub 2} and N{sub 2}, the oxy-coal combustion requires development of burner and boiler based on fundamental understanding of the flame shape, temperature, radiation and heat flux. For design of a new oxy-coal combustion system, computational fluid dynamics (CFD) is an essential tool to evaluate detailed combustion characteristics and supplement experimental results. In this study, CFD analysis was performed to understand the combustion characteristics inside a tangential vane swirl type 30 MW coal burner for air-mode and oxy-mode operations. In oxy-mode operations, various compositions of primary and secondary oxidizers were assessed which depended on the recirculation ratio of flue gas. For the simulations, devolatilization of coal and char burnout by O{sub 2}, CO{sub 2} and H{sub 2}O were predicted with a Lagrangian particle tracking method considering size distribution of pulverized coal and turbulent dispersion. The radiative heat transfer was solved by employing the discrete ordinate method with the weighted sum of gray gases model (WSGGM) optimized for oxy-coal combustion. In the simulation results for oxy-model operation, the reduced swirl strength of secondary oxidizer increased the flame length due to lower specific volume of CO{sub 2} than N{sub 2}. The flame length was also sensitive to the flow rate of primary oxidizer. The oxidizer without N{sub 2} that reduces thermal NO{sub x} formation makes the NO{sub x} lower in oxy-mode than air-mode. The predicted results showed similar trends with measured temperature profiles for various oxidizer compositions. Further numerical investigations are required to improve the burner design combined with more detailed experimental results.

  14. Coordinated Control of Cross-Flow Turbines

    Science.gov (United States)

    Strom, Benjamin; Brunton, Steven; Polagye, Brian

    2016-11-01

    Cross-flow turbines, also known as vertical-axis turbines, have several advantages over axial-flow turbines for a number of applications including urban wind power, high-density arrays, and marine or fluvial currents. By controlling the angular velocity applied to the turbine as a function of angular blade position, we have demonstrated a 79 percent increase in cross-flow turbine efficiency over constant-velocity control. This strategy uses the downhill simplex method to optimize control parameter profiles during operation of a model turbine in a recirculating water flume. This optimization method is extended to a set of two turbines, where the blade motions and position of the downstream turbine are optimized to beneficially interact with the coherent structures in the wake of the upstream turbine. This control scheme has the potential to enable high-density arrays of cross-flow turbines to operate at cost-effective efficiency. Turbine wake and force measurements are analyzed for insight into the effect of a coordinated control strategy.

  15. Declarative flow control for distributed instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Parvin, Bahram; Taylor, John; Fontenay, Gerald; Callahan, Daniel

    2001-06-01

    We have developed a 'microscopy channel' to advertise a unique set of on-line scientific instruments and to let users join a particular session, perform an experiment, collaborate with other users, and collect data for further analysis. The channel is a collaborative problem solving environment (CPSE) that allows for both synchronous and asynchronous collaboration, as well as flow control for enhanced scalability. The flow control is a declarative feature that enhances software functionality at the experimental scale. Our testbed includes several unique electron and optical microscopes with applications ranging from material science to cell biology. We have built a system that leverages current commercial CORBA services, Web Servers, and flow control specifications to meet diverse requirements for microscopy and experimental protocols. In this context, we have defined and enhanced Instrument Services (IS), Exchange Services (ES), Computational Services (CS), and Declarative Services (DS) that sit on top of CORBA and its enabling services (naming, trading, security, and notification) IS provides a layer of abstraction for controlling any type of microscope. ES provides a common set of utilities for information management and transaction. CS provides the analytical capabilities needed for online microscopy. DS provides mechanisms for flow control for improving the dynamic behavior of the system.

  16. Premixed burner experiments: Geometry, mixing, and flame structure issues

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, A.K.; Lewis, M.J.; Gupta, M. [Univ of Maryland, College Park, MD (United States)] [and others

    1995-10-01

    This research program is exploring techniques for improved fuel-air mixing, with the aim of achieving combustor operations up to stoichiometric conditions with minimal NO x and maximum efficiency. The experimental studies involve the use of a double-concentric natural gas burner that is operable in either premixed or non-premixed modes, and the system allows systematic variation of equivalence ratio, swirl strength shear length region and flow momentum in each annulus. Flame structures formed with various combinations of swirl strengths, flow throughput and equivalence ratios in premixed mode show the significant impact of swirl flow distribution on flame structure emanating from the mixedness. This impact on flame structure is expected to have a pronounced effect on the heat release rate and the emission of NO{sub x}. Thus, swirler design and configuration remains a key factor in the quest for completely optimized combustion. Parallel numerical studies of the flow and combustion phenomena were carried out, using the RSM and thek-{epsilon} turbulence models. These results have not only indicated the strengths and limitations of CFD in performance and pollutants emission predictions, but have provided guidelines on the size and strength of the recirculation produced and the spatio-temporal structure of the combustion flowfield. The first stage of parametric studies on geometry and operational parameters at Morgan State University have culminated in the completion of a one-dimensional flow code that is integrated with a solid, virtual model of the existing premixed burner. This coupling will provide the unique opportunity to study the impact of geometry on the flowfield and vice-versa, with particular emphasis on concurrent design optimization.

  17. Pollution active control: a strategy for a clean and efficient combustion; Le controle actif des polluants: une strategie pour une combustion propre et efficace

    Energy Technology Data Exchange (ETDEWEB)

    Lacas, F. [CNRS Ecole Centrale de Paris, 75 (France). Laboratoire E.M2.C

    1996-12-31

    The active control NOx reduction concept has been applied on two burners (20 kW and 840 kW), using a rotary valve enabling an excitation in the 100 to 1000 Hz band, that can be mounted on existing appliances such as domestic or industrial boilers. NOx level reduction may reach 15 pc for the 20 kW burner, 25 pc for the 840 kW burner with domestic fuel oil and 35 pc for the 840 kW burner using pyridine doped domestic fuel oil. Mechanisms are detailed through flow visualization, and consist mainly in an annular vortex inducing a fuel/air pre-mixing favourable to a large decrease in NOx generation level and establishing a staged process such as in re-burning processes. The pulsed combustion process may be also combined to other pollution control systems

  18. Fuel cell with internal flow control

    Science.gov (United States)

    Haltiner, Jr., Karl J.; Venkiteswaran, Arun [Karnataka, IN

    2012-06-12

    A fuel cell stack is provided with a plurality of fuel cell cassettes where each fuel cell cassette has a fuel cell with an anode and cathode. The fuel cell stack includes an anode supply chimney for supplying fuel to the anode of each fuel cell cassette, an anode return chimney for removing anode exhaust from the anode of each fuel cell cassette, a cathode supply chimney for supplying oxidant to the cathode of each fuel cell cassette, and a cathode return chimney for removing cathode exhaust from the cathode of each fuel cell cassette. A first fuel cell cassette includes a flow control member disposed between the anode supply chimney and the anode return chimney or between the cathode supply chimney and the cathode return chimney such that the flow control member provides a flow restriction different from at least one other fuel cell cassettes.

  19. Design and Realization of Intelligent Flow Controller

    Directory of Open Access Journals (Sweden)

    Jianxiong Ye

    2014-09-01

    Full Text Available According to accurate flow rate control requirements in large irrigation zone, a fuzzy controller with dead-band is designed on the characteristics analysis and comparison of PID and Fuzzy. The setting values of water flow for gates are determined by real-time water level detection sensors, and the realistic value of discharged water and gate opening are detected out with relative sensors, simulation manifest that the specific control strategy can adjust the gate swiftly in circumstance of huge offset, and regulate the gate slightly in time of small bias, it is realized with Siemens S315 PLC (Programmable Logical Controller and has being working steadily for 2 years, the aim of regulation is performed properly.

  20. On Bunsen Burners, Bacteria and the Bible

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 1; Issue 2. On Bunsen Burners, Bacteria and the Bible. Milind Watve. Classroom Volume 1 Issue 2 February 1996 pp 84-89. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/001/02/0084-0089 ...

  1. Control Flow Analysis for BioAmbients

    DEFF Research Database (Denmark)

    Nielson, Flemming; Nielson, Hanne Riis; Priami, C.

    2007-01-01

    This paper presents a static analysis for investigating properties of biological systems specified in BioAmbients. We exploit the control flow analysis to decode the bindings of variables induced by communications and to build a relation of the ambients that can interact with each other. We...

  2. X-29 vortex flow control tests

    Science.gov (United States)

    Hancock, Regis; Fullerton, Gordon

    1992-01-01

    A joint Air Force/NASA X-29 aircraft program to improve yaw control at high angle of attack using vortex flow control (VFC) is described. Directional VFC blowing proved to a be a powerful yaw moment generator and was very effective in overriding natural asymmetries, but was essentially ineffective in suppressing wing rock. Symmetric aft blowing also had little effect on suppressing wing rock.

  3. Numerical study of geometric parameters effecting temperature and thermal efficiency in a premix multi-hole flat flame burner

    International Nuclear Information System (INIS)

    Saberi Moghaddam, Mohammad Hossein; Saei Moghaddam, Mojtaba; Khorramdel, Mohammad

    2017-01-01

    This paper investigates the geometric parameters related to thermal efficiency and pollution emission of a multi-hole flat flame burner. Recent experimental studies indicate that such burners are significantly influenced by both the use of distribution mesh and the size of the diameter of the main and retention holes. The present study numerically simulated methane-air premixed combustion using a two-step mechanism and constant mass diffusivity for all species. The results indicate that the addition of distribution mesh leads to uniform flow and maximum temperature that will reduce NOx emissions. An increase in the diameter of the main holes increased the mass flow which increased the temperature, thermal efficiency and NOx emissions. The size of the retention holes should be considered to decrease the total flow velocity and bring the flame closer to the burner surface, although a diameter change did not considerably improve temperature and thermal efficiency. Ultimately, under temperature and pollutant emission constraints, the optimum diameters of the main and retention holes were determined to be 5 and 1.25 mm, respectively. - Highlights: • Using distribution mesh led to uniform flow and reduced Nox pollutant by 53%. • 93% of total heat transfer occurred by radiation method in multi-hole burner. • Employing retention hole caused the flame become closer to the burner surface.

  4. Core flow control system for field applications; Sistema de controle de core-flow

    Energy Technology Data Exchange (ETDEWEB)

    Granzotto, Desiree G.; Adachi, Vanessa Y.; Bannwart, Antonio C.; Moura, Luiz F.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Sassim, Natache S.D.A. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Centro de Estudo do Petroleo (CEPETRO); Carvalho, Carlos H.M. [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    The significant heavy oil reserves worldwide and the presently high crude oil prices make it essential the development of technologies for heavy oil production and transportation. Heavy oils, with their inherent features of high viscosity (100- 10,000 cP) and density (below 20 deg API) require specific techniques to make it viable their flow in pipes at high flow rates. One of the simplest methods, which do not require use of heat or diluents, is provided by oil-water annular flow (core-flow). Among the still unsolved issues regarding core-flow is the two-phase flow control in order to avoid abrupt increases in the pressure drop due to the possible occurrence of bad water-lubricated points, and thus obtain a safe operation of the line at the lowest possible water-oil ratio. This work presents results of core flow tests which allow designing a control system for the inlet pressure of the line, by actuating on the water flow rate at a fixed oil flow rate. With the circuit model and the specified controller, simulations can be done to assess its performance. The experiments were run at core-flow circuit of LABPETRO-UNICAMP. (author)

  5. Development of combined low-emissions burner devices for low-power boilers

    Science.gov (United States)

    Roslyakov, P. V.; Proskurin, Yu. V.; Khokhlov, D. A.

    2017-08-01

    Low-power water boilers are widely used for autonomous heat supply in various industries. Firetube and water-tube boilers of domestic and foreign manufacturers are widely represented on the Russian market. However, even Russian boilers are supplied with licensed foreign burner devices, which reduce their competitiveness and complicate operating conditions. A task of developing efficient domestic low-emissions burner devices for low-power boilers is quite acute. A characteristic property of ignition and fuel combustion in such boilers is their flowing in constrained conditions due to small dimensions of combustion chambers and flame tubes. These processes differ significantly from those in open combustion chambers of high-duty power boilers, and they have not been sufficiently studied yet. The goals of this paper are studying the processes of ignition and combustion of gaseous and liquid fuels, heat and mass transfer and NO x emissions in constrained conditions, and the development of a modern combined low-emissions 2.2 MW burner device that provides efficient fuel combustion. A burner device computer model is developed and numerical studies of its operation on different types of fuel in a working load range from 40 to 100% of the nominal are carried out. The main features of ignition and combustion of gaseous and liquid fuels in constrained conditions of the flame tube at nominal and decreased loads are determined, which differ fundamentally from the similar processes in steam boiler furnaces. The influence of the burner devices design and operating conditions on the fuel underburning and NO x formation is determined. Based on the results of the design studies, a design of the new combined low-emissions burner device is proposed, which has several advantages over the prototype.

  6. Case study for co and counter swirling domestic burners

    Directory of Open Access Journals (Sweden)

    Ashraf Kotb

    2018-03-01

    Full Text Available In this case study, the influence of equivalence ratio for co and counter-swirl domestic burners compared with non-swirl design on the thermal efficiency as well as CO emissions has been studied using liquefied petroleum gas (LPG. Also, the flame stability, and pot height, which is defined as the burner-to-pot distance (H, of the co and counter domestic burners were compared. The analysis of the results showed that, for both swirl burners co and counter one the thermal efficiency under all operation conditions tested is higher than the non-swirled burner (base burner. For example, the thermal efficiency increased by 8.8%, and 5.8% than base burner for co and counter swirl, respectively at Reynolds number equal 2000 and equivalence ratio 1. The co and counter swirl burners show lower CO emission than the base burner. The co swirl burner has wider operation range than counter swirl. With the increase of pot height, the thermal efficiency of all burners decreases because the flame and combustion gases are cooled due to mixing with ambient air. As a result, the heat transfer is decreased due to atmospheric loss, which decrease the thermal efficiency.

  7. IR sensor for monitoring of burner flame; IR sensor foer oevervakning av braennarflamma

    Energy Technology Data Exchange (ETDEWEB)

    Svanberg, Marcus; Funkquist, Jonas; Clausen, Soennik; Wetterstroem, Jonas

    2007-12-15

    To obtain a smooth operation of the coal-fired power plants many power plant managers have installed online mass flow measurement of coal to all burners. This signal is used to monitor the coal mass flow to the individual burner and match it with appropriate amount of air and also to monitor the distribution of coal between the burners. The online mass flow measurement system is very expensive (approximately 150 kEUR for ten burners) and is not beneficial for smaller plants. The accuracy of the measurement and the sample frequency are also questionable. The idea in this project has been to evaluate a cheaper system that can present the same information and may also provide better accuracy and faster sample frequency. The infrared sensor is a cheap narrow banded light emission sensor that can be placed in a water cooed probe. The sensor was directed at the burner flame and the emitted light was monitored. Through calibration the mass flow of coal can be presented. Two measurement campaigns were performed. Both campaigns were carried out in Nordjyllandsverket in Denmark even though the second campaign was planned to be in Uppsala. Due to severe problems in the Uppsala plant the campaign was moved to Nordjyllandsverket. The pre-requisites for the test plant were that online measurement of coal flow was installed. In Nordjyllandsverket 4 out of 16 burners have the mass flow measurement installed. Risoe Laboratories has vast experiences in the IR technology and they provided the IR sensing equipment. One IR sensor was placed in the flame guard position just behind the flame directed towards the ignition zone. A second sensor was placed at the boiler wall directed towards the flame. The boiler wall position did not give any results and the location was not used during the second campaign. The flame-guard-positioned-sensor- signal was thoroughly evaluated and the results show that there is a clear correlation between the coal mass flow and the IR sensor signal. Tests were

  8. Plasma actuators for bluff body flow control

    Science.gov (United States)

    Kozlov, Alexey V.

    The aerodynamic plasma actuators have shown to be efficient flow control devices in various applications. In this study the results of flow control experiments utilizing single dielectric barrier discharge plasma actuators to control flow separation and unsteady vortex shedding from a circular cylinder in cross-flow are reported. This work is motivated by the need to reduce landing gear noise for commercial transport aircraft via an effective streamlining created by the actuators. The experiments are performed at Re D = 20,000...164,000. Circular cylinders in cross-flow are chosen for study since they represent a generic flow geometry that is similar in all essential aspects to a landing gear oleo or strut. The minimization of the unsteady flow separation from the models and associated large-scale wake vorticity by using actuators reduces the radiated aerodynamic noise. Using either steady or unsteady actuation at ReD = 25,000, Karman shedding is totally eliminated, turbulence levels in the wake decrease significantly and near-field sound pressure levels are reduced by 13.3 dB. Unsteady actuation at an excitation frequency of St D = 1 is found to be most effective. The unsteady actuation also has the advantage that total suppression of shedding is achieved for a duty cycle of only 25%. However, since unsteady actuation is associated with an unsteady body force and produces a tone at the actuation frequency, steady actuation is more suitable for noise control applications. Two actuation strategies are used at ReD = 82,000: spanwise and streamwise oriented actuators. Near field microphone measurements in an anechoic wind tunnel and detailed study of the near wake using LDA are presented in the study. Both spanwise and streamwise actuators give nearly the same noise reduction level of 11.2 dB and 14.2 dB, respectively, and similar changes in the wake velocity profiles. The contribution of the actuator induced noise is found to be small compared to the natural shedding

  9. Characteristics of premixed flames stabilized in an axisymmetric curved-wall jet burner with tip modification

    KAUST Repository

    Kim, Daejoong

    2009-11-10

    The stabilization characteristics of premixed flames in an axisymmetric curved-wall jet burner have been experimentally investigated. This burner utilized the Coanda effect on top of a burner tip. The initially spherical burner tip was modified to a flat tip and a concave tip in order to improve flame stabilization by providing enough space for flow recirculation above the burner tip region. The flow characteristics have been visualized using a schlieren technique. Small-scale turbulence structure has been observed mainly in the interaction jet region (located downstream of the recirculation region) for large jet velocity (Reynolds number >11,500). An appreciable amount of air entrainment was exhibited from the half-angle of the jet spread, approximately 20. The averaged planar laser-induced fluorescence images of the flames for this large velocity demonstrated that the strong signal of OH radicals, representing reaction zones, existed in the recirculation zone, while it was weak in the interaction jet region due to intermittency and local extinction by the generation of small scale turbulence. The OH radical signals strengthened again in the merged jet region (downstream of the interaction jet region). In extreme cases of Reynolds number over 19,000, a unique flame exhibiting OH radicals only in the recirculation zone was observed for the concave tip. The flame stabilization has been mapped by varying jet velocity and equivalence ratio, and the result showed that the stabilization characteristics were improved appreciably from the initial spherical tip design, especially for rich mixtures. The flow fields measured by a laser Doppler velocimetry confirmed the existence of recirculation zone and the expansion of the recirculation zones for the modified tips. The temperature profile measured by a coherent anti-Stokes Raman spectroscopy exhibited an intermittent nature, especially near the recirculation zone.

  10. Drag Reduction by Laminar Flow Control

    Directory of Open Access Journals (Sweden)

    Nils Beck

    2018-01-01

    Full Text Available The Energy System Transition in Aviation research project of the Aeronautics Research Center Niedersachsen (NFL searches for potentially game-changing technologies to reduce the carbon footprint of aviation by promoting and enabling new propulsion and drag reduction technologies. The greatest potential for aerodynamic drag reduction is seen in laminar flow control by boundary layer suction. While most of the research so far has been on partial laminarization by application of Natural Laminar Flow (NLF and Hybrid Laminar Flow Control (HLFC to wings, complete laminarization of wings, tails and fuselages promises much higher gains. The potential drag reduction and suction requirements, including the necessary compressor power, are calculated on component level using a flow solver with viscid/inviscid coupling and a 3D Reynolds-Averaged Navier-Stokes (RANS solver. The effect on total aircraft drag is estimated for a state-of-the-art mid-range aircraft configuration using preliminary aircraft design methods, showing that total cruise drag can be halved compared to today’s turbulent aircraft.

  11. Arduino control of a pulsatile flow rig.

    Science.gov (United States)

    Drost, S; de Kruif, B J; Newport, D

    2018-01-01

    This note describes the design and testing of a programmable pulsatile flow pump using an Arduino micro-controller. The goal of this work is to build a compact and affordable system that can relatively easily be programmed to generate physiological waveforms. The system described here was designed to be used in an in-vitro set-up for vascular access hemodynamics research, and hence incorporates a gear pump that delivers a mean flow of 900 ml/min in a test flow loop, and a peak flow of 1106 ml/min. After a number of simple identification experiments to assess the dynamic behaviour of the system, a feed-forward control routine was implemented. The resulting system was shown to be able to produce the targeted representative waveform with less than 3.6% error. Finally, we outline how to further increase the accuracy of the system, and how to adapt it to specific user needs. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

  12. Catalytic burners in larger boiler appliances

    Energy Technology Data Exchange (ETDEWEB)

    Silversand, Fredrik; Persson, Mikael (Catator AB, Lund (Sweden))

    2009-02-15

    This project focuses on the scale up of a Catator's catalytic burner technology to enable retrofit installation in existing boilers and the design of new innovative combinations of catalytic burners and boilers. Different design approaches are discussed and evaluated in the report and suggestions are made concerning scale-up. Preliminary test data, extracted from a large boiler installation are discussed together with an accurate analysis of technical possibilities following an optimization of the boiler design to benefit from the advantages of catalytic combustion. The experimental work was conducted in close collaboration with ICI Caldaie (ICI), located in Verona, Italy. ICI is a leading European boiler manufacturer in the effect segment ranging from about 20 kWt to several MWt. The study shows that it is possibly to scale up the burner technology and to maintain low emissions. The boilers used in the study were designed around conventional combustion and were consequently not optimized for implementation of catalytic burners. From previous experiences it stands clear that the furnace volume can be dramatically decreased when applying catalytic combustion. In flame combustion, this volume is normally dimensioned to avoid flame impingement on cold surfaces and to facilitate completion of the gas-phase reactions. The emissions of nitrogen oxides can be reduced by decreasing the residence time in the furnace. Even with the over-dimensioned furnace used in this study, we easily reached emission values close to 35 mg/kWh. The emissions of carbon monoxide and unburned hydrocarbons were negligible (less than 5 ppmv). It is possible to decrease the emissions of nitrogen oxides further by designing the furnace/boiler around the catalytic burner, as suggested in the report. Simultaneously, the size of the boiler installation can be reduced greatly, which also will result in material savings, i.e. the production cost can be reduced. It is suggested to optimize the

  13. CFD simulations on marine burner flames

    DEFF Research Database (Denmark)

    Cafaggi, Giovanni; Jensen, Peter Arendt; Glarborg, Peter

    The marine industry is changing with new demands concerning high energy efficiency, fuel flexibility and lower emissions of NOX and SOX. A collaboration between the company Alfa Laval and Technical University of Denmark has been established to support the development of the next generation...... of marine burners. The resulting auxiliary boilers shall be compact and able to operate with different fuel types, while reducing NOX emissions. The specific boiler object of this study uses a swirl stabilized liquid fuel burner, with a pressure swirl spill-return atomizer (Fig.1). The combustion chamber...... is enclosed in a water jacket used for water heating and evaporation, and a convective heat exchanger at the furnace outlet super-heats the steam. The purpose of the present study is to gather detailed knowledge about the influence of fuel spray conditions on marine utility boiler flames. The main goal...

  14. CFD optimization of a pellet burner

    Directory of Open Access Journals (Sweden)

    Westerlund Lars B.

    2012-01-01

    Full Text Available Increased capacity of computers has made CFD technology attractive for the design of different apparatuses. Optimization of a pellet burner using CFD was investigated in this paper. To make the design tool work fast, an approach with only mixing of gases was simulated. Other important phenomena such as chemical reactions were omitted in order to speed up the design process. The original design of the burner gave unsatisfactory performance. The optimized design achieved from simulation was validated and the results show a significant improvement. The power output increased and the emission of unburned species decreased but could be further reduced. The contact time between combustion gases and secondary air was probably too short. An increased contact time in high temperature conditions would possibly improve the design further.

  15. PULSE DRYING EXPERIMENT AND BURNER CONSTRUCTION

    Energy Technology Data Exchange (ETDEWEB)

    Robert States

    2006-07-15

    Non steady impingement heat transfer is measured. Impingement heating consumes 130 T-BTU/Yr in paper drying, but is only 25% thermally efficient. Pulse impingement is experimentally shown to enhance heat transfer by 2.8, and may deliver thermal efficiencies near 85%. Experimental results uncovered heat transfer deviations from steady theory and from previous investigators, indicating the need for further study and a better theoretical framework. The pulse burner is described, and its roll in pulse impingement is analyzed.

  16. Thermal-hydraulics of actinide burner reactors

    International Nuclear Information System (INIS)

    Takizuka, Takakazu; Mukaiyama, Takehiko; Takano, Hideki; Ogawa, Toru; Osakabe, Masahiro.

    1989-07-01

    As a part of conceptual study of actinide burner reactors, core thermal-hydraulic analyses were conducted for two types of reactor concepts, namely (1) sodium-cooled actinide alloy fuel reactor, and (2) helium-cooled particle-bed reactor, to examine the feasibility of high power-density cores for efficient transmutation of actinides within the maximum allowable temperature limits of fuel and cladding. In addition, calculations were made on cooling of actinide fuel assembly. (author)

  17. Controlling flow time delays in flexible manufacturing cells

    NARCIS (Netherlands)

    Slomp, J.; Caprihan, R.; Bokhorst, J. A. C.

    2009-01-01

    Flow time delays in Flexible Manufacturing Cells (FMCs) are caused by transport and clamping/reclamping activities. This paper shows how dynamic scheduling parameters may control the flow times of jobs and the available task windows for flow time delays.

  18. Characterization of a new Hencken burner with a transition from a reducing-to-oxidizing environment for fundamental coal studies

    Science.gov (United States)

    Adeosun, Adewale; Huang, Qian; Li, Tianxiang; Gopan, Akshay; Wang, Xuebin; Li, Shuiqing; Axelbaum, Richard L.

    2018-02-01

    In pulverized coal burners, coal particles usually transition from a locally reducing environment to an oxidizing environment. The locally reducing environment in the near-burner region is due to a dense region of coal particles undergoing devolatilization. Following this region, the particles move into an oxidizing environment. This "reducing-to-oxidizing" transition can influence combustion processes such as ignition, particulate formation, and char burnout. To understand these processes at a fundamental level, a system is required that mimics such a transition. Hence, we have developed and characterized a two-stage Hencken burner to evaluate the effect of the reducing-to-oxidizing transition and particle-to-particle interaction (which characterizes dense region of coal particles) on ignition and ultrafine aerosol formation. The two-stage Hencken burner allows coal particles to experience a reducing environment followed by a transition to an oxidizing environment. This work presents the results of the design and characterization of the new two-stage Hencken burner and its new coal feeder. In a unique approach to the operation of the flat-flame of the Hencken burner, the flame configurations are operated as either a normal flame or inverse flame. Gas temperatures and oxygen concentrations for the Hencken burner are measured in reducing-to-oxidizing and oxidizing environments. The results show that stable flames with well-controlled conditions, relatively uniform temperatures, and species concentrations can be achieved in both flame configurations. This new Hencken burner provides an effective system for evaluating the effect of the reducing-to-oxidizing transition and particle-to-particle interaction on early-stage processes of coal combustion such as ignition and ultrafine particle formation.

  19. Pulverized straw combustion in a low-NOx multifuel burner

    DEFF Research Database (Denmark)

    Mandø, Matthias; Rosendahl, Lasse; Yin, Chungen

    2010-01-01

    A CFD simulation of pulverized coal and straw combustion using a commercial multifuel burner have been undertaken to examine the difference in combustion characteristics. Focus has also been directed to development of the modeling technique to deal with larger non-spherical straw particles...... and to determine the relative importance of different modeling choices for straw combustion. Investigated modeling choices encompass the particle size and shape distribution, the modification of particle motion and heating due to the departure from the spherical ideal, the devolatilization rate of straw......, the influence of inlet boundary conditions and the effect of particles on the carrier phase turbulence. It is concluded that straw combustion is associated with a significantly longer flame and smaller recirculation zones compared to coal combustion for the present air flow specifications. The particle size...

  20. Wake flow control using a dynamically controlled wind turbine

    Science.gov (United States)

    Castillo, Ricardo; Wang, Yeqin; Pol, Suhas; Swift, Andy; Hussain, Fazle; Westergaard, Carsten; Texas Tech University Team

    2016-11-01

    A wind tunnel based "Hyper Accelerated Wind Farm Kinematic-Control Simulator" (HAWKS) is being built at Texas Tech University to emulate controlled wind turbine flow physics. The HAWKS model turbine has pitch, yaw and speed control which is operated in real model time, similar to that of an equivalent full scale turbine. Also, similar to that of a full scale wind turbine, the controls are developed in a Matlab Simulink environment. The current diagnostic system consists of power, rotor position, rotor speed measurements and PIV wake characterization with four cameras. The setup allows up to 7D downstream of the rotor to be mapped. The purpose of HAWKS is to simulate control strategies at turnaround times much faster than CFD and full scale testing. The fundamental building blocks of the simulator have been tested, and demonstrate wake steering for both static and dynamic turbine actuation. Parameters which have been studied are yaw, rotor speed and combinations hereof. The measured wake deflections for static yaw cases are in agreement with previously reported research implying general applicability of the HAWKS platform for the purpose of manipulating the wake. In this presentation the general results will be introduced followed by an analysis of the wake turbulence and coherent structures when comparing static and dynamic flow cases. The outcome of such studies could ultimately support effective wind farm wake flow control strategies. Texas Emerging Technology Fund (ETF).

  1. Flow-controlled magnetic particle manipulation

    Science.gov (United States)

    Grate, Jay W [West Richland, WA; Bruckner-Lea, Cynthia J [Richland, WA; Holman, David A [Las Vegas, NV

    2011-02-22

    Inventive methods and apparatus are useful for collecting magnetic materials in one or more magnetic fields and resuspending the particles into a dispersion medium, and optionally repeating collection/resuspension one or more times in the same or a different medium, by controlling the direction and rate of fluid flow through a fluid flow path. The methods provide for contacting derivatized particles with test samples and reagents, removal of excess reagent, washing of magnetic material, and resuspension for analysis, among other uses. The methods are applicable to a wide variety of chemical and biological materials that are susceptible to magnetic labeling, including, for example, cells, viruses, oligonucleotides, proteins, hormones, receptor-ligand complexes, environmental contaminants and the like.

  2. Effect of energetic electrons on combustion of premixed burner flame

    Science.gov (United States)

    Sasaki, Koichi

    2011-10-01

    In many studies of plasma-assisted combustion, authors superpose discharges onto flames to control combustion reactions. This work is motivated by more fundamental point of view. The standpoint of this work is that flames themselves are already plasmas. We irradiated microwave power onto premixed burner flame with the intention of heating electrons in it. The microwave power was limited below the threshold for a discharge. We obtained the enhancement of burning velocity by the irradiation of the microwave power, which was understood by the shortening of the flame length. At the same time, we observed the increases in the optical emission intensities of OH and CH radicals. Despite the increases in the optical emission intensities, the optical emission spectra of OH and CH were not affected by the microwave irradiation, indicating that the enhancement of the burning velocity was not attributed to the increase in the gas temperature. On the other hand, we observed significant increase in the optical emission intensity of the second positive system of molecular nitrogen, which is a clear evidence for electron heating in the premixed burner flame. Therefore, it is considered that the enhancement of the burning velocity is obtained by nonequilibrium combustion chemistry which is driven by energetic electrons. By irradiating pulsed microwave power, we examined the time constants for the increases and decreases in the optical emission intensities of N2, OH, CH, and continuum radiation.

  3. Porosity effects in flame length of the porous burners

    Directory of Open Access Journals (Sweden)

    Fatemeh Bahadori

    2014-10-01

    Full Text Available Furnaces are the devices for providing heat to the industrial systems like boilers, gas turbines and etc. The main challenge of furnaces is emission of huge air pollutants. However, porous burners produce less contaminant compared to others. The quality of the combustion process in the porous burners depends on the length of flame in the porous medium. In this paper, the computational fluid dynamic (CFD is used to investigate the porosity effects on the flame length of the combustion process in porous burner. The simulation results demonstrate that increasing the porosity increases the flame length and the combustion zone extends forward. So, combustion quality increases and production of carbon monoxide decrease. It is possible to conclude that temperature distribution in low porosity burner is lower and more uniform than high porosity one. Therefore, by increasing the porosity of the burner, the production of nitrogen oxides increases. So, using an intermediate porosity in the burner appears to be reasonable.

  4. Flow Control Over Sharp-Edged Wings

    Science.gov (United States)

    2007-07-01

    Gad-el-Hak (2001) as the ability to actively or passively manipulate a flow field to effect a desired change. The challenge is to achieve that change...combinations. Been able to independently control both is a great challenge . These requirements may appear too stringent for the sharp- edged airfoils...06 0𔄁 08 09 lic Vlc Figure 22: Pressure distributions for Model B at a=13 °. Stations I (left); 2 (right) 1 , -2 1 F - [12 1 -6a -16 08 -08 06 -06

  5. Minor actinide transmutation using minor actinide burner reactors

    International Nuclear Information System (INIS)

    Mukaiyama, T.; Yoshida, H.; Gunji, Y.

    1991-01-01

    The concept of minor actinide burner reactor is proposed as an efficient way to transmute long-lived minor actinides in order to ease the burden of high-level radioactive waste disposal problem. Conceptual design study of minor actinide burner reactors was performed to obtain a reactor model with very hard neutron spectrum and very high neutron flux in which minor actinides can be fissioned efficiently. Two models of burner reactors were obtained, one with metal fuel core and the other with particle fuel core. Minor actinide transmutation by the actinide burner reactors is compared with that by power reactors from both the reactor physics and fuel cycle facilities view point. (author)

  6. 3-DIMENSIONAL SIMULATION AND FEASIBILITY STUDY OF BIOMASS/COAL CO-COMBUSTION BURNER

    Directory of Open Access Journals (Sweden)

    Nataliya DUNAYEVSKA

    2017-06-01

    Full Text Available Combustion of solid biomass mixed with coal in existing boilers not only reduces harmful emissions, but also allows diversifying the available fuel base. Such technology allows to implement the efficient use of food industry solid wastes, which otherwise would be dumped in piles, and thus produce harmful environmental impact. The geometrical models of research reactor and a burner thermal preprocessing of pulverized coal were developed and calculational meshes were generated. The geometrical model of the VGP-100Vpresents only fluid domain whereas the effect of cooled walls was substituted by the equivalent biudary conditions deruved on the basis of direct experimentation. The model of the VGP-100V allowed accounting for the specifics of radiative heat transfer by comparison of experimental thermo-couple measurements to the simulated by the model one. A model has been developed allowing the determination of actual temperatures of combustion gases flow based upon the reading of unsheathed thermo-couples by taking into account the reradiation of the thermo-couple beads to the channel walls. Based on the ANSYS 3-D process model in the burner of the Trypilska Thermal Power Plant (TPP for the combustion of low-reactive coal with the thermochemical preparation of the design of an actual burner has been developed. On the basis of the experimental studies of the actual burner and the above-mentioned CFD calculations, the burner draft of the 65 MW for TPP-210A boiler aimed at the implementation of biomass-coal co-combustion was designed.

  7. Active Control of Jet Engine Inlet Flows

    National Research Council Canada - National Science Library

    Rediniotis, Othon; Bowersox, Rodney; Kirk, Aaron; Kumar, Abhinav; Tichenor, Nathan

    2007-01-01

    ...), flow visualization tests, particle image velocimetry (PIV), pressure probe and wall static tap experiments at various locations, the development and evolution of the secondary flow structures were observed...

  8. Optimization of gas mixing system of premixed burner based on CFD analysis

    International Nuclear Information System (INIS)

    Zhang, Tian-Hu; Liu, Feng-Guo; You, Xue-Yi

    2014-01-01

    Highlights: • New multi-ejectors gas mixing system for premixed combustion burner is provided. • Two measures are proposed to improve the flow uniformity at the outlet of GMS. • Small improvement of uniformity induces significant decrease of pollutant emission. • Uniformity of velocity and fuel–gas mixing of ejector increases 234.2% and 2.9%. • Uniformity of flow rate and fuel–gas mixing of ejectors increases 1.9% and 2.2%. - Abstract: The optimization of gas mixing system (GMS) of premixed burner is presented by Computational Fluid Dynamics (CFD) and the uniformity at the outlet of GMS is proved experimentally to have strong influence on pollutant emission. To improve the uniformity at the outlet of GMS, the eleven distribution orifice plates and a diversion plate are introduced. The quantified analysis shows that the uniformity at the outlet of GMS is improved significantly. With applying the distribution orifice plates, the uniformity of velocity and fuel–gas mixing of single ejector is increased by 234.2% and 2.9%, respectively. With applying the diversion plate, the uniformity of flow rate and fuel–gas mixing of different ejectors is increased by 1.9% and 2.2%, respectively. The optimal measures and geometrical parameters provide an applicable guidance for the design of commercial premixed burner

  9. The influence of burner material properties on the acoustical transfer function of radiant surface burners

    NARCIS (Netherlands)

    Schreel, K.R.A.M.; Tillaart, van den E.L.; Goey, de L.P.H.

    2005-01-01

    Modern central heating systems use low NO$_x$ premixed burners with a largemodulation range. This can lead to noise problems which cannot be solved viatrial and error, but need accurate modelling. An acoustical analysis as part ofthe design phase can reduce the time-to-market considerably, but the

  10. Studies on a burner used biomass pellets as fuel. Performance of a spiral vortex pellet burner

    Energy Technology Data Exchange (ETDEWEB)

    Iwao, Toshio

    1987-12-21

    In order to develop a small size burner with high performance using biomass pellets fuel substitute for fuel oil, the burning performance of a spiral vortex pallet burner has been studied. An experimental equipment for the pellet burning is made up of a fuel supply unit, combustion chamber and a furnace. The used woody pellet is made of mixed sawdust and bark; with water content of 10.29%, particle diameter of 5.5-9mm, length of 5-50mm, and, apparent and real specific gravities are 0.59 and 1.334 respectively. The pellets are sent to bottom of the combustion chamber, spiral vortex combustion are carried out with blown air, the ashes and unburnt residues are discharged to out of combustion chamber with spiral vortex hot gases. As the result, it was clarified that the formation of the burning layers in a burner is required to be in order of the layers of ash, oxidation, reduction and carbonization up to the upper layer for high burning performance, and the formation of the layer is influenced by the condition of sedimentation of pellets in the combustion chamber. In the meanwhile the burning performance of the burner is influenced by the quantity of blast, the rate of feeding, and by the time of pre-heating in the combustion chamber. (23 figs, 5 refs)

  11. Effect of Flow Rate Controller on Liquid Steel Flow in Continuous Casting Mold using Numerical Modeling

    Science.gov (United States)

    Gursoy, Kadir Ali; Yavuz, Mehmet Metin

    2014-11-01

    In continuous casting operation of steel, the flow through tundish to the mold can be controlled by different flow rate control systems including stopper rod and slide-gate. Ladle changes in continuous casting machines result in liquid steel level changes in tundishes. During this transient event of production, the flow rate controller opening is increased to reduce the pressure drop across the opening which helps to keep the mass flow rate at the desired level for the reduced liquid steel level in tundish. In the present study, computational fluid dynamic (CFD) models are developed to investigate the effect of flow rate controller on mold flow structure, and particularly to understand the effect of flow controller opening on meniscus flow. First, a detailed validation of the CFD models is conducted using available experimental data and the performances of different turbulence models are compared. Then, the constant throughput casting operations for different flow rate controller openings are simulated to quantify the opening effect on meniscus region. The results indicate that the meniscus velocities are significantly affected by the flow rate controller and its opening level. The steady state operations, specified as constant throughput casting, do not provide the same mold flow if the controller opening is altered. Thus, for quality and castability purposes, adjusting the flow controller opening to obtain the fixed mold flow structure is proposed. Supported by Middle East Technical University (METU) BAP (Scientific Research Projects) Coordination.

  12. Curved wall-jet burner for synthesizing titania and silica nanoparticles

    KAUST Repository

    Ismail, Mohamed

    2015-01-01

    A novel curved wall-jet (CWJ) burner was designed for flame synthesis, by injecting precursors through a center tube and by supplying fuel/air mixtures as an annular-inward jet for rapid mixing of the precursors in the reaction zone. Titanium dioxide (TiO2) and silicon dioxide (SiO2) nanoparticles were produced in ethylene (C2H4)/air premixed flames using titanium tetraisopropoxide (TTIP) and hexamethyldisiloxane (HMDSO) as the precursors, respectively. Particle image velocimetry measurements confirmed that the precursors can be injected into the flames without appreciably affecting flow structure. The nanoparticles were characterized using X-ray diffraction, Raman spectroscopy, the Brunauer-Emmett-Teller (BET) method, and high-resolution transmission electron microscopy. In the case of TiO2, the phase of nanoparticles could be controlled by adjusting the equivalence ratio, while the particle size was dependent on the precursor loading rate and the flame temperature. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence ratios (φ > 1.3). In the case of SiO2, the particle size could be controlled from 11 to 18 nm by adjusting the precursor loading rate. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

  13. Access control mechanism of wireless gateway based on open flow

    Science.gov (United States)

    Peng, Rong; Ding, Lei

    2017-08-01

    In order to realize the access control of wireless gateway and improve the access control of wireless gateway devices, an access control mechanism of SDN architecture which is based on Open vSwitch is proposed. The mechanism utilizes the features of the controller--centralized control and programmable. Controller send access control flow table based on the business logic. Open vSwitch helps achieve a specific access control strategy based on the flow table.

  14. Some parameters and conditions defining the efficiency of burners ...

    Indian Academy of Sciences (India)

    irradiation in special burners, namely, in the blankets of ADS. Various views ... Ecologic gain – ratio of the ecologic threat level of initial LLW to that of final. LLW. .... For all burner types, the general tendency is that the increase of consumption.

  15. Exposure calculation code module for reactor core analysis: BURNER

    Energy Technology Data Exchange (ETDEWEB)

    Vondy, D.R.; Cunningham, G.W.

    1979-02-01

    The code module BURNER for nuclear reactor exposure calculations is presented. The computer requirements are shown, as are the reference data and interface data file requirements, and the programmed equations and procedure of calculation are described. The operating history of a reactor is followed over the period between solutions of the space, energy neutronics problem. The end-of-period nuclide concentrations are determined given the necessary information. A steady state, continuous fueling model is treated in addition to the usual fixed fuel model. The control options provide flexibility to select among an unusually wide variety of programmed procedures. The code also provides user option to make a number of auxiliary calculations and print such information as the local gamma source, cumulative exposure, and a fine scale power density distribution in a selected zone. The code is used locally in a system for computation which contains the VENTURE diffusion theory neutronics code and other modules.

  16. Exposure calculation code module for reactor core analysis: BURNER

    International Nuclear Information System (INIS)

    Vondy, D.R.; Cunningham, G.W.

    1979-02-01

    The code module BURNER for nuclear reactor exposure calculations is presented. The computer requirements are shown, as are the reference data and interface data file requirements, and the programmed equations and procedure of calculation are described. The operating history of a reactor is followed over the period between solutions of the space, energy neutronics problem. The end-of-period nuclide concentrations are determined given the necessary information. A steady state, continuous fueling model is treated in addition to the usual fixed fuel model. The control options provide flexibility to select among an unusually wide variety of programmed procedures. The code also provides user option to make a number of auxiliary calculations and print such information as the local gamma source, cumulative exposure, and a fine scale power density distribution in a selected zone. The code is used locally in a system for computation which contains the VENTURE diffusion theory neutronics code and other modules

  17. 0.20-m (8-in.) primary burner development report

    International Nuclear Information System (INIS)

    Stula, R.T.; Young, D.T.; Rode, J.S.

    1977-12-01

    High-Temperature Gas-Cooled Reactors (HTGRs) utilize graphite-base fuels. Fluidized-bed burners are being employed successfully in the experimental reprocessing of these fuels. The primary fluidized-bed burner is a unit operation in the reprocessing flowsheet in which the graphite moderator is removed. A detailed description of the development status of the 0.20-m (8-in.) diameter primary fluidized-bed burner as of July 1, 1977 is presented. Experimental work to date performed in 0.10; 0.20; and 0.40-m (4, 8, and 16 in.) diameter primary burners has demonstrated the feasibility of the primary burning process and, at the same time, has defined more clearly the areas in which additional experimental work is required. The design and recent operating history of the 0.20-m-diameter burner are discussed, with emphasis placed upon the evolution of the current design and operating philosophy

  18. Glial and neuronal control of brain blood flow

    DEFF Research Database (Denmark)

    Attwell, David; Buchan, Alastair M; Charpak, Serge

    2010-01-01

    Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now...... in our understanding of cerebral blood flow control have important implications for the development of new therapeutic approaches....

  19. Emissions of Jatropha oil-derived biodiesel blend fuels during combustion in a swirl burner

    Science.gov (United States)

    Norwazan, A. R.; Mohd. Jaafar, M. N.; Sapee, S.; Farouk, Hazir

    2018-03-01

    Experimental works on combustion of jatropha oil biodiesel blends of fuel with high swirling flow in swirl burner have been studied in various blends percentage. Jatropha oil biodiesel was produced using a two-step of esterification-transesterification process. The paper focuses on the emissions of biodiesel blends fuel using jatropha oil in lean through to rich air/fuel mixture combustion in swirl burner. The emissions performances were evaluated by using axial swirler amongst jatropha oil blends fuel including diesel fuel as baseline. The results show that the B25 has good emissions even though it has a higher emission of NOx than diesel fuel, while it emits as low as 42% of CO, 33% of SO2 and 50% of UHC emissions with high swirl number. These are due to the higher oxygen content in jatropha oil biodiesel.

  20. Sensor Development for Active Flow Control

    Science.gov (United States)

    Kahng, Seun K.; Gorton, Susan A.; Mau, Johnney C.; Soto, Hector L.; Hernandez, Corey D.

    2001-01-01

    Presented are the developmental efforts for MEMS sensors for a closed-loop active flow control in a low-speed wind tunnel evaluation. The MEMS sensors are designed in-house and fabricated out of house, and the shear sensors are a thermal type that are collocated with temperature and pressure sensors on a flexible polyimide sheet, which conforms to surfaces of a simple curvature. A total of 6 sensors are located within a 1.5 by 3 mm area as a cluster with each sensor being 300 pm square. The thickness of this sensor cluster is 75 pm. Outputs from the shear sensors have been compared with respect to those of the Preston tube for evaluation of the sensors on a flat plate. Pressure sensors are the absolute type and have recorded pressure measurements within 0.05 percent of the tunnel ESP pressure sensor readings. The sensors and signal conditioning electronics have been tested on both a flat plate and a ramp in Langley s 15-Inch Low-Turbulence Tunnel. The system configuration and control PC is configured with LabView, where calibration constants are stored for desired compensation and correction. The preliminary test results are presented within.

  1. Flow Control Device Evaluation for an Internal Flow with an Adverse Pressure Gradient

    Science.gov (United States)

    Jenkins, Luther N.; Gorton, Susan Althoff; Anders, Scott G.

    2002-01-01

    The effectiveness of several active and passive devices to control flow in an adverse pressure gradient with secondary flows present was evaluated in the 15 Inch Low Speed Tunnel at NASA Langley Research Center. In this study, passive micro vortex generators, micro bumps, and piezoelectric synthetic jets were evaluated for their flow control characteristics using surface static pressures, flow visualization, and 3D Stereo Digital Particle Image Velocimetry. Data also were acquired for synthetic jet actuators in a zero flow environment. It was found that the micro vortex generator is very effective in controlling the flow environment for an adverse pressure gradient, even in the presence of secondary vortical flow. The mechanism by which the control is effected is a re-energization of the boundary layer through flow mixing. The piezoelectric synthetic jet actuators must have sufficient velocity output to produce strong longitudinal vortices if they are to be effective for flow control. The output of these devices in a laboratory or zero flow environment will be different than the output in a flow environment. In this investigation, the output was higher in the flow environment, but the stroke cycle in the flow did not indicate a positive inflow into the synthetic jet.

  2. Glial and neuronal control of brain blood flow

    DEFF Research Database (Denmark)

    Attwell, David; Buchan, Alastair M; Charpak, Serge

    2010-01-01

    Blood flow in the brain is regulated by neurons and astrocytes. Knowledge of how these cells control blood flow is crucial for understanding how neural computation is powered, for interpreting functional imaging scans of brains, and for developing treatments for neurological disorders. It is now...... recognized that neurotransmitter-mediated signalling has a key role in regulating cerebral blood flow, that much of this control is mediated by astrocytes, that oxygen modulates blood flow regulation, and that blood flow may be controlled by capillaries as well as by arterioles. These conceptual shifts...

  3. Recent progress in flow control for practical flows results of the STADYWICO and IMESCON projects

    CERN Document Server

    Barakos, George; Luczak, Marcin

    2017-01-01

    This book explores the outcomes on flow control research activities carried out within the framework of two EU-funded projects focused on training-through-research of Marie Sklodowska-Curie doctoral students. The main goal of the projects described in this monograph is to assess the potential of the passive- and active-flow control methods for reduction of fuel consumption by a helicopter. The research scope encompasses the fields of structural dynamics, fluid flow dynamics, and actuators with control. Research featured in this volume demonstrates an experimental and numerical approach with a strong emphasis on the verification and validation of numerical models. The book is ideal for engineers, students, and researchers interested in the multidisciplinary field of flow control. Provides highly relevant and up-to-date information on the topic of flow control; Includes assessments of a wide range of flow-control technologies and application examples for fixed and rotary-wing configurations; Reinforces reader u...

  4. Improving Software Systems By Flow Control Analysis

    Directory of Open Access Journals (Sweden)

    Piotr Poznanski

    2012-01-01

    Full Text Available Using agile methods during the implementation of the system that meets mission critical requirements can be a real challenge. The change in the system built of dozens or even hundreds of specialized devices with embedded software requires the cooperation of a large group of engineers. This article presents a solution that supports parallel work of groups of system analysts and software developers. Deployment of formal rules to the requirements written in natural language enables using formal analysis of artifacts being a bridge between software and system requirements. Formalism and textual form of requirements allowed the automatic generation of message flow graph for the (sub system, called the “big-picture-model”. Flow diagram analysis helped to avoid a large number of defects whose repair cost in extreme cases could undermine the legitimacy of agile methods in projects of this scale. Retrospectively, a reduction of technical debt was observed. Continuous analysis of the “big picture model” improves the control of the quality parameters of the software architecture. The article also tries to explain why the commercial platform based on UML modeling language may not be sufficient in projects of this complexity.

  5. Review of hybrid laminar flow control systems

    Science.gov (United States)

    Krishnan, K. S. G.; Bertram, O.; Seibel, O.

    2017-08-01

    The aeronautic community always strived for fuel efficient aircraft and presently, the need for ecofriendly aircraft is even more, especially with the tremendous growth of air traffic and growing environmental concerns. Some of the important drivers for such interests include high fuel prices, less emissions requirements, need for more environment friendly aircraft to lessen the global warming effects. Hybrid laminar flow control (HLFC) technology is promising and offers possibility to achieve these goals. This technology was researched for decades for its application in transport aircraft, and it has achieved a new level of maturity towards integration and safety and maintenance aspects. This paper aims to give an overview of HLFC systems research and associated flight tests in the past years both in the US and in Europe. The review makes it possible to distinguish between the successful approaches and the less successful or outdated approaches in HLFC research. Furthermore, the technology status shall try to produce first estimations regarding the mass, power consumption and performance of HLFC systems as well as estimations regarding maintenance requirements and possible subsystem definitions.

  6. Preliminary design and analysis on nuclear fuel cycle for fission-fusion hybrid spent fuel burner

    International Nuclear Information System (INIS)

    Chen Yan; Wang Minghuang; Jiang Jieqiong

    2012-01-01

    A wet-processing-based fuel cycle and a dry-processing were designed for a fission-fusion hybrid spent fuel burner (FDS-SFB). Mass flow of SFB was preliminarily analyzed. The feasibility analysis of initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing were preliminarily evaluated. The results of mass flow of FDS-SFB demonstrated that the initial loaded fuel inventory, recycle fuel fabrication and spent fuel reprocessing of nuclear fuel cycle of FDS-SFB is preliminarily feasible. (authors)

  7. Molten salt burner fuel behaviour and treatment

    International Nuclear Information System (INIS)

    Ignatiev, V.V.; Zakirov, R.Y.; Grebenkine, K.F.

    2001-01-01

    The objective of this paper is to discuss the feasibility of molten salt reactor technology for treatment of Pu, minor actinides and fission products, when the reactor and fission product clean-up unit are planned as an integral system. This contribution summarises the available R and D which led to selection of the fuel compositions for the molten salt reactor of the TRU burner type (MSB). Special characteristics of behaviour of TRUs and fission products during power operation of MSB concepts are presented. The present paper briefly reviews the processing developments underlying the prior molten salt reactor programmes and relates them to the separation requirements of the MSB concept, including the permissible range of processing cycle times and removal times. Status and development needs in the thermodynamic properties of fluorides, fission product clean-up methods and container materials compatibility with the working fluids for the fission product clean-up unit are discussed. (authors)

  8. AGA answers complaints on burner tip prices

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper reports that the American Gas Association has rebutted complaints that natural gas prices have dropped at the wellhead but not at the burner tip. AGA Pres. Mike Baly the an association study of the issue found that all classes of customers paid less for gas in 1991 than they did in 1984, when gas prices were at their peak. He the, the study also shows that 100% of the wellhead price decline has been passed through to natural gas consumers in the form of lower retail prices. Baly the the average cost of gas delivered to all customers classes fell by $1.12/Mcf from 1984 to 1991, which exceeds the $1.10/Mcf decline in average wellhead prices during the same period

  9. Experimental investigation of combustion instabilities in lean swirl-stabilized partially-premixed flames in single- and multiple-burner setup

    Directory of Open Access Journals (Sweden)

    Christian Kraus

    2016-03-01

    Full Text Available In the present work, combustion instabilities of a modular combustor are investigated. The combustor operates with partially premixed, swirl-stabilized flames and can be operated in single- and different multiple-burner setups. The design parameters of the combustor prevent large-scale flame–flame interactions in the multiple-burner arrangements. The objective is to investigate how the interaction of the swirl jets affects the thermoacoustic stability of the combustor. Results of measurements of pressure oscillations and high-speed OH*-chemiluminescence imaging for the single-burner setup and two multiple-burner setups are discussed. Additionally, results of investigations with different flame characteristics are presented. These are achieved by varying the ratio of the mass flow rates through the swirlers of the double-concentric swirl nozzle. Several unstable modes with high pressure amplitudes are observed in the single-burner setup as well as in the multiple-burner setups. Numerical studies of the acoustic behavior of the combustor setups were performed that indicate that the different geometries show similar acoustic behaviors. The results lead to the conclusion that the interaction of the swirl jets in the multiple-burner setups affects the thermoacoustic response spectrum of the flame even in the absence of large-scale flame–flame interactions. Based on the findings in earlier studies, it is concluded that the differences in the flame response characteristics are induced by the reduction of the swirl intensity in the multiple-burner arrangements, which is caused by the exchange of momentum between the adjacent swirl jets.

  10. Firing in fluid beds and burners

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, F.; Lans, R. van der; Storm Pedersen, L.; Philbert Nielsen, H.; Aslaug Hansen, L.; Lin, W.; Johnsson, J.E.; Dam-Johansen, K.

    1998-02-01

    An investigation of the effect of co-firing straw and pulverized coal was performed. Based on experiments from pilot-scale and full-scale it was concluded that a higher fraction of straw in the fuel feedstock mixture results in lower NO and SO{sub 2} emissions. The lower NO emission was mainly due to the higher volatile content of the straw, which leads to lower stoichiometry in the gas phase and in subsequent suppression of NO{sub x} formation. This conclusion is consistent with experimental and modeling results for pure coal combustion. The effect of coal quality on NO emissions has been investigated with three coals of different characteristics in three furnaces: in the Funen power station, unit 7 (FVO7), the Midtkraft Studstrup power station, unit 4 (MKS4), and the Mitsui Babcock Energy Ltd (MBEL) test-rig. The MBEL test-rig was able to reproduce qualitatively the emissions from the MKS4 plant, and quantitatively the emissions from the FVO7 plant. The better agreement between the MBEL test-rig and FVO7 is presumed to be related to the existence of a large primary zone with a relatively low stoichiometry, diminishing the influence of near burner air and fuel mixing rate on the NO emissions. An engineering model has been developed for the prediction of NO emissions and burnout from pulverized fuel combustion in swirl burners. A simplified model for reduction of N{sub 2}O in CFBC has been developed, and simulation results are in good agreement with experimental data from a 12 MW{sub th} CFB-boiler. (EG) EFP-94. 108 refs.

  11. Electroosmotically controllable multi-flow microreactor

    NARCIS (Netherlands)

    Kohlheyer, D.; Besselink, G.A.J.; Lammertink, Rob G.H.; Schlautmann, Stefan; Unnikrishnan, S.; Schasfoort, Richardus B.M.

    2005-01-01

    An adjustable diffusion-based microfluidic reactor is presented here, which is based on electro-osmotic guiding of reagent samples. The device consists of a laminar flow chamber with two separate reagent inlets. The position and the width of the two sample streams in the flow chamber can be

  12. Flow Control for Supersonic Inlet Applications

    Science.gov (United States)

    2014-06-10

    1221-1233, May 2013 3. Loth, E., Titchener, N., Babinsky, H., Povinelli , L., “Canonical NSBLI Flows Relevant to External Compression Inlets”, AIAA J...Tennessee, Jan. 9-12, 2012 7. Loth, E.L., Titchener, N., Babinsky, H., Povinelli , L.A., “A Canonical Normal SBLI Flow Relevant to External

  13. Use of UPFC device controlled by fuzzy logic controllers for decoupled power flow control

    Directory of Open Access Journals (Sweden)

    Ivković Sanja

    2014-01-01

    Full Text Available This paper investigates the possibility of decoupled active and reactive power flow control in a power system using a UPFC device controlled by fuzzy logic controllers. A Brief theoretical review of the operation principles and applications of UPFC devices and design principles of the fuzzy logic controller used are given. A Matlab/Simulink model of the system with UPFC, the fuzzy controller setup, and graphs of the results are presented. Conclusions are drawn regarding the possibility of using this system for decoupled control of the power flow in power systems based on analysis of these graphs.

  14. Control of District Heating System with Flow-dependent Delays

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Ledesma, Jorge Val; Kallesøe, Carsten Skovmose

    2017-01-01

    All flow systems are subject to transport delays, which are governed by the flow rates in the system. When the flow rates themselves are control inputs, the system becomes subject to input-dependent state delays, which poses significant theoretical problems. In an earlier paper, we proposed...

  15. Numerical investigation of premixed combustion in a porous burner with integrated heat exchanger

    Energy Technology Data Exchange (ETDEWEB)

    Farzaneh, Meisam; Shafiey, Mohammad; Shams, Mehrzad [K.N. Toosi University of Technology, Department of Mechanical Engineering, Tehran (Iran, Islamic Republic of); Ebrahimi, Reza [K.N. Toosi University of Technology, Department of Aerospace Engineering, Tehran (Iran, Islamic Republic of)

    2012-07-15

    In this paper, we perform a numerical analysis of a two-dimensional axisymmetric problem arising in premixed combustion in a porous burner with integrated heat exchanger. The physical domain consists of two zones, porous and heat exchanger zones. Two dimensional Navier-Stokes equations, gas and solid energy equations, and chemical species transport equations are solved and heat release is described by a multistep kinetics mechanism. The solid matrix is modeled as a gray medium, and the finite volume method is used to solve the radiative transfer equation to calculate the local radiation source/sink in the solid phase energy equation. Special attention is given to model heat transfer between the hot gas and the heat exchanger tube. Thus, the corresponding terms are added to the energy equations of the flow and the solid matrix. Gas and solid temperature profiles and species mole fractions on the burner centerline, predicted 2D temperature fields, species concentrations and streamlines are presented. Calculated results for temperature profiles are compared to experimental data. It is shown that there is good agreement between the numerical solutions and the experimental data and it is concluded that the developed numerical program is an excellent tool to investigate combustion in porous burner. (orig.)

  16. The art and science of flow control - case studies using flow visualization methods

    Science.gov (United States)

    Alvi, F. S.; Cattafesta, L. N., III

    2010-04-01

    Active flow control (AFC) has been the focus of significant research in the last decade. This is mainly due to the potentially substantial benefits it affords. AFC applications range from the subsonic to the supersonic (and beyond) regime for both internal and external flows. These applications are wide and varied, such as controlling flow transition and separation over various external components of the aircraft to active management of separation and flow distortion in engine components and over turbine and compressor blades. High-speed AFC applications include control of flow oscillations in cavity flows, supersonic jet screech, impinging jets, and jet-noise control. In this paper we review some of our recent applications of AFC through a number of case studies that illustrate the typical benefits as well as limitations of present AFC methods. The case studies include subsonic and supersonic canonical flowfields such as separation control over airfoils, control of supersonic cavity flows and impinging jets. In addition, properties of zero-net mass-flux (ZNMF) actuators are also discussed as they represent one of the most widely studied actuators used for AFC. In keeping with the theme of this special issue, the flowfield properties and their response to actuation are examined through the use of various qualitative and quantitative flow visualization methods, such as smoke, shadowgraph, schlieren, planar-laser scattering, and Particle image velocimetry (PIV). The results presented here clearly illustrate the merits of using flow visualization to gain significant insight into the flow and its response to AFC.

  17. Thaw flow control for liquid heat transport systems

    Science.gov (United States)

    Kirpich, Aaron S.

    1989-01-01

    In a liquid metal heat transport system including a source of thaw heat for use in a space reactor power system, the thaw flow throttle or control comprises a fluid passage having forward and reverse flow sections and a partition having a plurality of bleed holes therein to enable fluid flow between the forward and reverse sections. The flow throttle is positioned in the system relatively far from the source of thaw heat.

  18. Surface ignition behaviors of methane–air mixture in a gas oven burner

    International Nuclear Information System (INIS)

    Ryu, Jungwan; Kwon, Jongseo; Kim, Ryanggyun; Kim, Minseong; Kim, Youngsoo; Jeon, Chunghwan; Song, Juhun

    2014-01-01

    In a gas oven burner, commonly used as a residential appliance, a surface igniter is a critical component for creating a pilot flame near the surface that can propagate safely back to the nozzle of the burner. The igniter should meet critical operating requirements: a lower surface temperature needed to ignite a methane–air mixture and a stable/safe ignition sustained. Otherwise, such failure would result in an instantaneous peak in carbon monoxide emission and a safety hazard inside a closed oven. Several theoretical correlations have been used to predict ignition temperature as well as the critical ignition/extinction limit for a stagnation flow ignition. However, there have only been a few studies on ignition modes or relevant stability analysis, and therefore a more detailed examination of the transient ignition process is required. In this study, a high-speed flame visualization technique with temperature measurement was employed to reveal a surface ignition phenomenon and subsequent flame propagation of a cold combustible methane–air mixture in a gas oven burner. The operating parameters were the temperature–time history of the igniter surface, mixture velocity, and the distance of the igniter from the nozzle. The surface ignition temperatures were analyzed for such parameters under a safe ignition mode, while several abnormal modes leading to ignition failure were also recognized. - Highlights: •We revealed a surface ignition behavior of combustible mixture in gas oven burner. •We employed a flame visualization technique with temperature measurement. •We evaluated effects of parameters such as lifetime, mixture velocity and igniter distance. •We recognized several abnormal modes leading to ignition failure

  19. Microjet flow control in an ultra-compact serpentine inlet

    Directory of Open Access Journals (Sweden)

    Da Xingya

    2015-10-01

    Full Text Available Microjets are used to control the internal flow to improve the performance of an ultra-compact serpentine inlet. A highly offset serpentine inlet with length-to-diameter ratio of 2.5 is designed and static tests are conducted to analyze the internal flow characteristics in terms of pressure recovery, distortion and flow separation. Flow separation is encountered in the second S-turn, and two strong counter-rotating vortices are formed at the aerodynamic interface plane (AIP face which occupy a quarter of the outlet area and result in severe pressure loss and distortion. A flow control model employing a row of microjets in the second turn is designed based on the internal flow characteristics and simplified CFD simulations. Flow control tests are conducted to verify the control effectiveness and understand the characteristics as a function of inlet throat Mach number, injection mass flow ratio, jet Mach number and momentum coefficient. At all test Mach numbers, microjet flow control (MFC effectively improves the recovery and reduces the distortion intensity. Between inlet throat Mach number 0.2 and 0.5, the strong flow separation in the second S-turn is suppressed at an optimum jet flow ratio of less than 0.65%, resulting in a maximum improvement of 4% for pressure recovery coefficient and a maximum decrease of 75% for circumferential distortion intensity at cruise. However, in order to suppress the flow separation, the injection rate should retain in an effective range. When the injection rate is higher than this range, the flow is degraded and the distortion contour is changed from 90° circumferential distortion pattern to 180° circumferential distortion pattern. Detailed data analysis shows that this optimum flow ratio depends on inlet throat Mach number and the momentum coefficient affects the control effectiveness in a dual stepping manner.

  20. Boundary control of fluid flow through porous media

    DEFF Research Database (Denmark)

    Hasan, Agus; Foss, Bjarne; Sagatun, Svein Ivar

    2010-01-01

    The flow of fluids through porous media can be described by the Boussinesq’s equation with mixed boundary conditions; a Neumann’s boundary condition and a nonlinear boundary condition. The nonlinear boundary condition provides a means to control the fluid flow through porous media. In this paper,......, some stabilizing controllers are constructed for various cases using Lyapunov design.......The flow of fluids through porous media can be described by the Boussinesq’s equation with mixed boundary conditions; a Neumann’s boundary condition and a nonlinear boundary condition. The nonlinear boundary condition provides a means to control the fluid flow through porous media. In this paper...

  1. Plasma Control of Turbine Secondary Flows, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose Phase I and II efforts that will focus on turbomachinery flow control. Specifically, the present work will investigate active control in a high speed...

  2. Information-flow-based Access Control for Virtualized Systems

    Directory of Open Access Journals (Sweden)

    Dmitriy Aleksandrovich Postoev

    2014-12-01

    Full Text Available The article is devoted to the method of information-flow-based access control, adopted for virtualized systems. General structure of access control system for virtual infrastructure is proposed.

  3. Development of strand burner for solid propellant burning rate studies

    International Nuclear Information System (INIS)

    Aziz, A; Mamat, R; Ali, W K Wan

    2013-01-01

    It is well-known that a strand burner is an apparatus that provides burning rate measurements of a solid propellant at an elevated pressure in order to obtain the burning characteristics of a propellant. This paper describes the facilities developed by author that was used in his studies. The burning rate characteristics of solid propellant have be evaluated over five different chamber pressures ranging from 1 atm to 31 atm using a strand burner. The strand burner has a mounting stand that allows the propellant strand to be mounted vertically. The strand was ignited electrically using hot wire, and the burning time was recorded by electronic timer. Wire technique was used to measure the burning rate. Preliminary results from these techniques are presented. This study shows that the strand burner can be used on propellant strands to obtain accurate low pressure burning rate data

  4. Evaluating the efficacy of a minor actinide burner

    International Nuclear Information System (INIS)

    Dobbin, K.D.; Kessler, S.F.; Nelson, J.V.; Omberg, R.P.; Wootan, D.W.

    1993-06-01

    The efficacy of a minor actinide burner can be evaluated by comparing safety and economic parameters to the support ratio. Minor actinide mass produced per unit time in this number of Light Water Reactors (LWRs) can be burned during the same time period in one burner system. The larger the support ratio for a given set of safety and economic parameters, the better. To illustrate this concept, the support ratio for selected Liquid Metal Reactor (LMR) burner core designs was compared with corresponding coolant void worths, a fundamental safety concern following the Chernobyl accident. Results can be used to evaluate the cost in reduced burning of minor actinides caused by LMR sodium void reduction efforts or to compare with other minor actinide burner systems

  5. Assessment of PWR plutonium burners for nuclear energy centers

    International Nuclear Information System (INIS)

    Frankel, A.J.; Shapiro, N.L.

    1976-06-01

    The purpose of the study was to explore the performance and safety characteristics of PWR plutonium burners, to identify modifications to current PWR designs to enhance plutonium utilization, to study the problems of deploying plutonium burners at Nuclear Energy Centers, and to assess current industrial capability of the design and licensing of such reactors. A plutonium burner is defined to be a reactor which utilizes plutonium as the sole fissile addition to the natural or depleted uranium which comprises the greater part of the fuel mass. The results of the study and the design analyses performed during the development of C-E's System 80 plant indicate that the use of suitably designed plutonium burners at Nuclear Energy Centers is technically feasible

  6. State Space Reduction of Linear Processes using Control Flow Reconstruction

    NARCIS (Netherlands)

    van de Pol, Jan Cornelis; Timmer, Mark

    2009-01-01

    We present a new method for fighting the state space explosion of process algebraic specifications, by performing static analysis on an intermediate format: linear process equations (LPEs). Our method consists of two steps: (1) we reconstruct the LPE's control flow, detecting control flow parameters

  7. State Space Reduction of Linear Processes Using Control Flow Reconstruction

    NARCIS (Netherlands)

    van de Pol, Jan Cornelis; Timmer, Mark; Liu, Zhiming; Ravn, Anders P.

    2009-01-01

    We present a new method for fighting the state space explosion of process algebraic specifications, by performing static analysis on an intermediate format: linear process equations (LPEs). Our method consists of two steps: (1) we reconstruct the LPE's control flow, detecting control flow parameters

  8. SPIV study of passive flow control on a WT airfoil

    DEFF Research Database (Denmark)

    Velte, Clara Marika; Hansen, Martin Otto Laver; Meyer, Knud Erik

    2010-01-01

    to free stream velocity U=15 m/s. The objective was to investigate the flow structures induced by and separation controlling behavior of vortex generators on the airfoil. The experimental results show strong separation of the uncontrolled flow whereas an intermittent behavior appears for the controlled...

  9. Power flow analysis for DC voltage droop controlled DC microgrids

    DEFF Research Database (Denmark)

    Li, Chendan; Chaudhary, Sanjay; Dragicevic, Tomislav

    2014-01-01

    This paper proposes a new algorithm for power flow analysis in droop controlled DC microgrids. By considering the droop control in the power flow analysis for the DC microgrid, when compared with traditional methods, more accurate analysis results can be obtained. The algorithm verification is ca...

  10. Synthesis of Titanium Dioxide Nanoparticles Using a Double-Slit Curved Wall-Jet Burner

    KAUST Repository

    Ismail, Mohamed

    2016-05-04

    A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide (TTIP) precursor while the outer one was to supply premixed fuel/air mixture of ethylene (C2H4) or propane (C3H8). This configuration enabled rapid mixing between the precursor and reactants along the curved surface and inside the recirculation zone of the burner. Particle growth of titanium dioxide (TiO2) nanoparticles and their phases was investigated with varying equivalence ratio and Reynolds number. Flow field and flame structure were measured using particle image velocimetry (PIV) and OH planar laser-induced fluorescence (PLIF) techniques, respectively. The nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and nitrogen adsorption Brunauer–Emmett–Teller (BET) for surface area analysis. The flow field consisted of a wall-jet region leading to a recirculation zone, an interaction jet region, followed by a merged-jet region. The DS-CWJ burner revealed appreciable mixing characteristics between the precursor and combustion gases near the nozzle regions, with a slight increase in the axial velocity due to the precursor injection. The precursor supply had a negligible effect on the flame structure. The burner produced a reasonably uniform size (13–18 nm) nanoparticles with a high BET surface area (>100 m2/g). The phase of TiO2 nanoparticles was mainly dependent on the equivalence ratio and fuel type, which impact flame height, heat release rate, and high temperature residence time of the precursor vapor. For ethylene flames, the anatase content increased with the equivalence ratio, whereas it decreased in the case of propane flames. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence

  11. Advanced burner test reactor preconceptual design report.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y. I.; Finck, P. J.; Grandy, C.; Cahalan, J.; Deitrich, L.; Dunn, F.; Fallin, D.; Farmer, M.; Fanning, T.; Kim, T.; Krajtl, L.; Lomperski, S.; Moisseytsev, A.; Momozaki, Y.; Sienicki, J.; Park, Y.; Tang, Y.; Reed, C.; Tzanos, C; Wiedmeyer, S.; Yang, W.; Chikazawa, Y.; JAEA

    2008-12-16

    The goals of the Global Nuclear Energy Partnership (GNEP) are to expand the use of nuclear energy to meet increasing global energy demand, to address nuclear waste management concerns and to promote non-proliferation. Implementation of the GNEP requires development and demonstration of three major technologies: (1) Light water reactor (LWR) spent fuel separations technologies that will recover transuranics to be recycled for fuel but not separate plutonium from other transuranics, thereby providing proliferation-resistance; (2) Advanced Burner Reactors (ABRs) based on a fast spectrum that transmute the recycled transuranics to produce energy while also reducing the long term radiotoxicity and decay heat loading in the repository; and (3) Fast reactor fuel recycling technologies to recover and refabricate the transuranics for repeated recycling in the fast reactor system. The primary mission of the ABR Program is to demonstrate the transmutation of transuranics recovered from the LWR spent fuel, and hence the benefits of the fuel cycle closure to nuclear waste management. The transmutation, or burning of the transuranics is accomplished by fissioning and this is most effectively done in a fast spectrum. In the thermal spectrum of commercial LWRs, some transuranics capture neutrons and become even heavier transuranics rather than being fissioned. Even with repeated recycling, only about 30% can be transmuted, which is an intrinsic limitation of all thermal spectrum reactors. Only in a fast spectrum can all transuranics be effectively fissioned to eliminate their long-term radiotoxicity and decay heat. The Advanced Burner Test Reactor (ABTR) is the first step in demonstrating the transmutation technologies. It directly supports development of a prototype full-scale Advanced Burner Reactor, which would be followed by commercial deployment of ABRs. The primary objectives of the ABTR are: (1) To demonstrate reactor-based transmutation of transuranics as part of an

  12. Reactor core flow rate control system

    International Nuclear Information System (INIS)

    Sakuma, Hitoshi; Tanikawa, Naoshi; Takahashi, Toshiyuki; Miyakawa, Tetsuya.

    1996-01-01

    When an internal pump is started by a variable frequency power source device, if magnetic fields of an AC generator are introduced after the rated speed is reached, neutron flux high scram occurs by abrupt increase of a reactor core flow rate. Then, in the present invention, magnetic fields for the AC generator are introduced at a speed previously set at which the fluctuation range of the reactor core flow rate (neutron flux) by the start up of the internal pump is within an allowable value. Since increase of the speed of the internal pump upon its start up is suppressed to determine the change of the reactor core flow rate within an allowable range, increase of neutron fluxes is suppressed to enable stable start up. Then, since transition boiling of fuels caused by abrupt decrease of the reactor core flow rate upon occurrence of abnormality in an external electric power system is prevented, and the magnetic fields for the AC generator are introduced in such a manner to put the speed increase fluctuation range of the internal pump upon start up within an allowable value, neutron flux high scram is not caused to enable stable start-up. (N.H.)

  13. Modeling and control of compressor flow instabilities

    NARCIS (Netherlands)

    Willems, F.P.T.; Jager, de A.G.

    1999-01-01

    Compressors are widely used for the pressurization of fluids. Applications involve air compression for use in aircraft engines and pressurization and transportation of gas in the process and chemical industries. The article focuses on two commonly used types of continuous flow compressors: the axial

  14. ISS Payload Racks Automated Flow Control Calibration Method

    Science.gov (United States)

    Simmonds, Boris G.

    2003-01-01

    Payload Racks utilize MTL and/or LTL station water for cooling of payloads and avionics. Flow control range from valves of fully closed, to up to 300 Ibmhr. Instrument accuracies are as high as f 7.5 Ibm/hr for flow sensors and f 3 Ibm/hr for valve controller, for a total system accuracy of f 10.5 Ibm/hr. Improved methodology was developed, tested and proven that reduces accuracy of the commanded flows to less than f 1 Ibmhr. Uethodology could be packed in a "calibration kit" for on- orbit flow sensor checkout and recalibration, extending the rack operations before return to earth. -

  15. Linear accelerator for burner-reactor

    International Nuclear Information System (INIS)

    Batskikh, G.I.; Murin, B.P.; Fedotov, A.P.

    1991-01-01

    Future development of nuclear power engineering depends on the successful solution of two key problems of safety and utilization of high level radioactive wastes (HLRW) of atomic power plants (APP). Modern methods of HLRW treatment involve solidification, preliminary storing for a period of 30-50 years necessary for the decay of long-living nuclides and final burial in geological formations several hundred meters below the ground surface. The depth burial of the radioactive wastes requires complicated under ground constructions. It's very expensive and doesn't meet modern ecological requirements. Alternative modern and more reasonable methods of APP HLRW treatment are under consideration now. One of the methods involves separation of APP waste radionuclides for use in economy with subsequent transmutation of the long-living isotopes into the short-living ones by high-intensity neutron fluxes generated by proton accelerators. The installation intended for the long-living radionuclides transmutation into the short-living ones is called burner-reactor. It can be based on the continuous regime proton accelerator with 1.5 GeV energy, 0.3 A current and beam mean power of 450 MW. The preferable type of the proton accelerator with the aforementioned parameters is the linear accelerator

  16. Low Emissions Burner Technology for Metal Processing Industry using Byproducts and Biomass Derived Liquid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Ajay; Taylor, Robert

    2013-09-30

    This research and development efforts produced low-emission burner technology capable of operating on natural gas as well as crude glycerin and/or fatty acids generated in biodiesel plants. The research was conducted in three stages (1) Concept definition leading to the design and development of a small laboratory scale burner, (2) Scale-up to prototype burner design and development, and (3) Technology demonstration with field vefiication. The burner design relies upon the Flow Blurring (FB) fuel injection based on aerodynamically creating two-phase flow near the injector exit. The fuel tube and discharge orifice both of inside diameter D are separated by gap H. For H < 0.25D, the atomizing air bubbles into liquid fuel to create a two-phase flow near the tip of the fuel tube. Pressurized two-phase fuel-air mixture exits through the discharge orifice, which results in expansion and breakup of air bubbles yielding a spray with fine droplets. First, low-emission combustion of diesel, biodiesel and straight VO (soybean oil) was achieved by utilizing FB injector to yield fine sprays for these fuels with significantly different physical properties. Visual images for these baseline experiments conducted with heat release rate (HRR) of about 8 kW illustrate clean blue flames indicating premixed combustion for all three fuels. Radial profiles of the product gas temperature at the combustor exit overlap each other signifying that the combustion efficiency is independent of the fuel. At the combustor exit, the NOx emissions are within the measurement uncertainties, while CO emissions are slightly higher for straight VO as compared to diesel and biodiesel. Considering the large variations in physical and chemical properties of fuels considered, the small differences observed in CO and NOx emissions show promise for fuel-flexible, clean combustion systems. FB injector has proven to be very effective in atomizing fuels with very different physical properties, and it offers a

  17. CFD simulation of a burner for syngas characterization and experimental validation

    Energy Technology Data Exchange (ETDEWEB)

    Fantozzi, Francesco; Desideri, Umberto [University of Perugia (Italy). Dept. of Industrial Engineering], Emails: fanto@unipg.it, umberto.desideri@unipg.it; D' Amico, Michele [University of Perugia (Italy). Dept. of Energetic Engineering], E-mail: damico@crbnet.it

    2009-07-01

    Biomass and waste are distributed and renewable energy sources that may contribute effectively to sustainability if used on a small and micro scale. This requires the transformation through efficient technologies (gasification, pyrolysis and anaerobic digestion) into a suitable gaseous fuel to use in small internal combustion engines and gas turbines. The characterization of biomass derived syngas during combustion is therefore a key issue to improve the performance of small scale integrated plants because synthesis gas show significant differences with respect to Natural Gas (mixture of gases, low calorific value, hydrogen content, tar and particulate content) that may turn into ignition problems, combustion instabilities, difficulties in emission control and fouling. To this aim a burner for syngas combustion and LHV measurement through mass and energy balance was realized and connected to the rotary-kiln laboratory scale pyrolyzer at the Department of Industrial Engineering of the University of Perugia. A computational fluid dynamics (CFD) simulation of the burner was carried out considering the combustion of propane to investigate temperature and pressure distribution, heat transmission and distribution of the combustion products and by products. The simulation was carried out using the CFD program Star-CD. Before the simulation a geometrical model of the burner was built and the volume of model was subdivided in cells. A sensibility analysis of cells was carried out to estimate the approximation degree of the model. Experimental data about combustion emission were carried out with the propane combustion in the burner, the comparison between numerical results and experimental data was studied to validate the simulation for future works involved with the combustion of treated or raw (syngas with tar) syngas obtained from pyrolysis process. (author)

  18. Measurement and control systems for an imaging electromagnetic flow metre.

    Science.gov (United States)

    Zhao, Y Y; Lucas, G; Leeungculsatien, T

    2014-03-01

    Electromagnetic flow metres based on the principles of Faraday's laws of induction have been used successfully in many industries. The conventional electromagnetic flow metre can measure the mean liquid velocity in axisymmetric single phase flows. However, in order to achieve velocity profile measurements in single phase flows with non-uniform velocity profiles, a novel imaging electromagnetic flow metre (IEF) has been developed which is described in this paper. The novel electromagnetic flow metre which is based on the 'weight value' theory to reconstruct velocity profiles is interfaced with a 'Microrobotics VM1' microcontroller as a stand-alone unit. The work undertaken in the paper demonstrates that an imaging electromagnetic flow metre for liquid velocity profile measurement is an instrument that is highly suited for control via a microcontroller. © 2013 ISA Published by ISA All rights reserved.

  19. Effect of the superposition of a dielectric barrier discharge onto a premixed gas burner flame

    Science.gov (United States)

    Zaima, Kazunori; Takada, Noriharu; Sasaki, Koichi

    2011-10-01

    We are investigating combustion control with the help of nonequilibrium plasma. In this work, we examined the effect of dielectric barrier discharge (DBD) on a premixed burner flame with CH4/O2/Ar gas mixture. The premixed burner flame was covered with a quartz tube. A copper electrode was attached on the outside of the quartz tube, and it was connected to a high-voltage power supply. DBD inside the quartz tube was obtained between the copper electrode and the grounded nozzle of the burner which was placed at the bottom of the quartz tube. We clearly observed that the flame length was shortened by superposing DBD onto the bottom part of the flame. The shortened flame length indicates the enhancement of the burning velocity. We measured the optical emission spectra from the bottom region of the flame. As a result, we observed clear line emissions from Ar, which were never observed from the flame without DBD. We evaluated the rotational temperatures of OH and CH radicals by spectral fitting. As a result, the rotational temperature of CH was not changed, and the rotational temperature of OH was decreased by the superposition of DBD. According to these results, it is considered that the enhancement of the burning velocity is not caused by gas heating. New reaction pathways are suggested.

  20. Suboptimal control for drag reduction in turbulent pipe flow

    International Nuclear Information System (INIS)

    Choi, Jung Il; Sung, Hyung Jin; Xu, Chun Xiao

    2001-01-01

    A suboptimal control law in turbulent pipe flow is derived and tested. Two sensing variables ∂ρ/∂θ / w and ∂ν θ /∂r / w are applied with two actuations φ θ and φ γ . To test the suboptimal control law, direct numerical simulations of turbulent pipe flow at Re τ =150 are performed. When the control law is applied, a 13∼23% drag reduction is achieved. The most effective drag reduction is made at the pair of ∂υ θ /∂r / w and φ γ . An impenetrable virtual wall concept is useful for analyzing the near-wall suction and blowing. The virtual wall concept is useful for analyzing the near-wall behavior of the controlled flow. Comparison of the present suboptimal control with that of turbulent channel flow reveals that the curvature effect is insignificant

  1. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Science.gov (United States)

    Cary, Robert E.

    2015-12-08

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  2. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Energy Technology Data Exchange (ETDEWEB)

    Cary, Robert B.

    2018-04-17

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  3. Photothermally controlled Marangoni flow around a micro bubble

    International Nuclear Information System (INIS)

    Namura, Kyoko; Nakajima, Kaoru; Kimura, Kenji; Suzuki, Motofumi

    2015-01-01

    We have experimentally investigated the control of Marangoni flow around a micro bubble using photothermal conversion. Using a focused laser spot acting as a highly localized heat source on Au nanoparticles/dielectric/Ag mirror thin film enables us to create a micro bubble and to control the temperature gradient around the bubble at a micrometer scale. When we irradiate the laser next to the bubble, a strong main flow towards the bubble and two symmetric rotation flows on either side of it develop. The shape of this rotation flow shows a significant transformation depending on the relative position of the bubble and the laser spot. Using this controllable rotation flow, we have demonstrated sorting of the polystyrene spheres with diameters of 2 μm and 0.75 μm according to their size

  4. Photothermally controlled Marangoni flow around a micro bubble

    Science.gov (United States)

    Namura, Kyoko; Nakajima, Kaoru; Kimura, Kenji; Suzuki, Motofumi

    2015-01-01

    We have experimentally investigated the control of Marangoni flow around a micro bubble using photothermal conversion. Using a focused laser spot acting as a highly localized heat source on Au nanoparticles/dielectric/Ag mirror thin film enables us to create a micro bubble and to control the temperature gradient around the bubble at a micrometer scale. When we irradiate the laser next to the bubble, a strong main flow towards the bubble and two symmetric rotation flows on either side of it develop. The shape of this rotation flow shows a significant transformation depending on the relative position of the bubble and the laser spot. Using this controllable rotation flow, we have demonstrated sorting of the polystyrene spheres with diameters of 2 μm and 0.75 μm according to their size.

  5. International Conference on Instability and Control of Massively Separated Flows

    CERN Document Server

    Soria, Julio

    2015-01-01

    This book contains the outcome of the international meeting on instability, control and noise generated by massive flow separation that was organized at the Monash Center, in Prato, Italy, September 4-6, 2013. The meeting served as the final review of the EU-FP7 Instability and Control of Massively Separated Flows Marie Curie travel grant and was supported by the European Office of Aerospace Research and Development. Fifty leading specialists from twelve countries reviewed the progress made since the 50s of the last century and discussed modern analysis techniques, advanced experimental flow diagnostics, and recent developments in active flow control techniques from the incompressible to the hypersonic regime. Applications involving massive flow separation and associated instability and noise generation mechanisms of interest to the aeronautical, naval and automotive industries have been addressed from a theoretical, numerical or experimental point of view, making this book a unique source containing the stat...

  6. Control of flow geometry using electromagnetic body forcing

    International Nuclear Information System (INIS)

    Rossi, L.; Bocquet, S.; Ferrari, S.; Garcia de la Cruz, J.M.; Lardeau, S.

    2009-01-01

    This paper presents conceptual experiments and simulations aiming at controlling flow geometries. Such flow design is performed by driving electromagnetically a shallow layer of brine, the forcing being generated by a transverse electrical current and different combinations of permanent magnets placed underneath the brine supporting wall. It is shown how different basic flow characteristics can be obtained with a single pair of magnets, by varying the angle with the electrical current. These basic flows are proposed as potential building blocks for advanced and complex flows studies. Three typical flow structures are presented to illustrate these building blocks. The discussion is then extended to multi-scale geometry by using blocks of various sizes. The flow is analysed using complementary experiments and numerical simulations. A good agreement is found between the 3D simulations and the experiments for both velocity and acceleration fields, which allows a higher degree of confidence in designing and modelling such flows. As the control of the flow geometry is important for mixing, in particular at low Reynolds number, we also illustrate the different stirring properties of the electromagnetically forced flows by comparing visualisations of passive scalars. They reveal complementary mixing properties for each of the building blocks.

  7. Influence of burner form and pellet type on domestic pellet boiler performance

    Science.gov (United States)

    Rastvorov, D. V.; Osintsev, K. V.; Toropov, E. V.

    2017-10-01

    The study presents combustion and emission results obtained using two serial pellet boilers of the same heating capacity 40 kW. These boilers have been designed by producers for domestic conditions of exploitation. The principal difference between boilers was the type of the burner. The study concerns the efficiency and ecological performance difference between burners of circular and rectangular forms. The features of the combustion process in both types of burners were studied when boiler operated with different sorts of pellets. The results suggest that the burner of circular form excels the rectangular form burner. However, there is some difference of NOx emission between circular and rectangular burners.

  8. Power flow control of intertied ac microgrids

    DEFF Research Database (Denmark)

    Nutkani, Inam Ullah; Loh, Poh Chiang; Blaabjerg, Frede

    2013-01-01

    Microgrids are small reliable grids formed by clustering distributed sources and loads together. They can, in principle, operate at different voltages and frequencies like 50, 60, 400 Hz or even dc. Tying them together or to the mains grid for energy sharing would therefore require the insertion...... of interlinking power converters. Active and reactive power flows of these converters should preferably be managed autonomously without demanding for fast communication links. A scheme that can fulfill the objectives is now proposed, which upon realised, will result in more robustly integrated microgrids...

  9. Automatic coolant flow control device for a nuclear reactor assembly

    Science.gov (United States)

    Hutter, Ernest

    1986-01-01

    A device which controls coolant flow through a nuclear reactor assembly comprises a baffle means at the exit end of said assembly having a plurality of orifices, and a bimetallic member in operative relation to the baffle means such that at increased temperatures said bimetallic member deforms to unblock some of said orifices and allow increased coolant flow therethrough.

  10. The Combination of Micro Diaphragm Pumps and Flow Sensors for Single Stroke Based Liquid Flow Control

    Directory of Open Access Journals (Sweden)

    Christoph Jenke

    2017-04-01

    Full Text Available With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout—differential pressure based flow sensors and thermal calorimetric flow sensors—are evaluated for their suitability of combining them with mircopumps. Single stroke based calibration of the sensors was carried out with a new method, comparing displacement volumes and sensor flow volumes. Limitations of accuracy and performance for single stroke based flow control are described. Results showed that besides particle robustness of sensors, controlling resistive and capacitive damping are key aspects for setting up reproducible and reliable liquid dosing systems. Depending on the required average flow or defined volume, dosing systems with an accuracy of better than 5% for the differential pressure based sensor and better than 6.5% for the thermal calorimeter were achieved.

  11. The Combination of Micro Diaphragm Pumps and Flow Sensors for Single Stroke Based Liquid Flow Control.

    Science.gov (United States)

    Jenke, Christoph; Pallejà Rubio, Jaume; Kibler, Sebastian; Häfner, Johannes; Richter, Martin; Kutter, Christoph

    2017-04-03

    With the combination of micropumps and flow sensors, highly accurate and secure closed-loop controlled micro dosing systems for liquids are possible. Implementing a single stroke based control mode with piezoelectrically driven micro diaphragm pumps can provide a solution for dosing of volumes down to nanoliters or variable average flow rates in the range of nL/min to μL/min. However, sensor technologies feature a yet undetermined accuracy for measuring highly pulsatile micropump flow. Two miniaturizable in-line sensor types providing electrical readout-differential pressure based flow sensors and thermal calorimetric flow sensors-are evaluated for their suitability of combining them with mircopumps. Single stroke based calibration of the sensors was carried out with a new method, comparing displacement volumes and sensor flow volumes. Limitations of accuracy and performance for single stroke based flow control are described. Results showed that besides particle robustness of sensors, controlling resistive and capacitive damping are key aspects for setting up reproducible and reliable liquid dosing systems. Depending on the required average flow or defined volume, dosing systems with an accuracy of better than 5% for the differential pressure based sensor and better than 6.5% for the thermal calorimeter were achieved.

  12. On load flow control in electric power systems

    Energy Technology Data Exchange (ETDEWEB)

    Herbig, Arnim

    2000-01-01

    This dissertation deals with the control of active power flow, or load flow in electric power systems. During the last few years, interest in the possibilities to control the active power flows in transmission systems has increased significantly. There is a number of reasons for this, coming both from the application side - that is, from power system operations - and from the technological side. where advances in power electronics and related technologies have made new system components available. Load flow control is by nature a multi-input multi-output problem, since any change of load flow in one line will be complemented by changes in other lines. Strong cross-coupling between controllable components is to be expected, and the possibility of adverse interactions between these components cannot be rejected straightaway. Interactions with dynamic phenomena in the power system are also a source of concern. Three controllable components are investigated in this thesis, namely the controlled series capacitor (CSC), the phase angle regulator (PAR), and the unified power flow controller (UPFC). Properties and characteristics of these devices axe investigated and discussed. A simple control strategy is proposed. This strategy is then analyzed extensively. Mathematical methods and physical knowledge about the pertinent phenomena are combined, and it is shown that this control strategy can be used for a fairly general class of devices. Computer simulations of the controlled system provide insight into the system behavior in a system of reasonable size. The robustness and stability of the control system are discussed as are its limits. Further, the behavior of the control strategy in a system where the modeling allows for dynamic phenomena are investigated with computer simulations. It is discussed under which circumstances the control action has beneficial or detrimental effect on the system dynamics. Finally, a graphical approach for analyzing the effect of controllers

  13. Usefulness of DC power flow for active power flow analysis with flow controlling devices

    NARCIS (Netherlands)

    Van Hertem, D.; Verboomen, J.; Purchala, K.; Belmans, R.; Kling, W.L.

    2006-01-01

    DC power flow is a commonly used tool for contingency analysis. Recently, due to its simplicity and robustness, it also becomes increasingly used for the real-time dispatch and techno-economic analysis of power systems. It is a simplification of a full power flow looking only at active power.

  14. Pick'n'Fix: Capturing Control Flow in Modular Compilers

    DEFF Research Database (Denmark)

    Day, Laurence E.; Bahr, Patrick

    2014-01-01

    structures, in particular cyclic ones, we employ Oliveira and Cook's purely functional representation of graphs. Moreover, to separate control flow features semantically from other language features, we represent source languages using Johann and Ghani's encoding of generalised algebraic datatypes...

  15. RETROFITTING CONTROL FACILITIES FOR WET-WEATHER FLOW TREATMENT

    Science.gov (United States)

    Available technologies were evaluated to demonstrate the technical feasibility and cost effectiveness of retrofitting existing facilities to handle wet-weather flow. Cost/benefit relationships were also compared to construction of new conventional control and treatment facilities...

  16. Orifice design for the control of coupled region flow

    International Nuclear Information System (INIS)

    Atherton, R.; Spadaro, P.R.; Brummerhop, F.G.

    1975-01-01

    A fluid system arrangement for nuclear reactors is described comprising a triplate orifice apparatus which simultaneously controls core flow distribution, flow rate ratio between hydraulically coupled regions of the blanket and radial static pressure gradients entering and leaving the blanket fuel region. The design of the apparatus is based on the parameters of the diameter of the orifice holes, the friction factor, and expansion, contraction and turning pressure loss coefficients of the geometry of each orifice region. These above parameters are properly matched to provide the desired pressure drop, flow split and negligible cross flow at the interface of standard and power-flattened open lattice blanket regions. (U.S.)

  17. Central recirculation zone analysis in an unconfined tangential swirl burner with varying degrees of premixing

    Energy Technology Data Exchange (ETDEWEB)

    Valera-Medina, A. [CIATEQ, Parque Industrial Bernardo Quintana, Turbomachinery Department, Queretaro (Mexico); Syred, N.; Kay, P.; Griffiths, A. [Cardiff University, School of Engineering, Cardiff, Wales (United Kingdom)

    2011-06-15

    Swirl-stabilised combustion is one of the most widely used techniques for flame stabilisation, uses ranging from gas turbine combustors to pulverised coal-fired power stations. In gas turbines, lean premixed systems are of especial importance, giving the ability to produce low NOx systems coupled with wide stability limits. The common element is the swirl burner, which depends on the generation of an aerodynamically formed central recirculation zone (CRZ) and which serves to recycle heat and active chemical species to the root of the flame as well as providing low-velocity regions where the flame speed can match the local flow velocity. Enhanced mixing in and around the CRZ is another beneficial feature. The structure of the CRZ and hence that of the associated flames, stabilisation and mixing processes have shown to be extremely complex, three-dimensional and time dependent. The characteristics of the CRZ depend very strongly on the level of swirl (swirl number), burner configuration, type of flow expansion, Reynolds number (i.e. flowrate) and equivalence ratio. Although numerical methods have had some success when compared to experimental results, the models still have difficulties at medium to high swirl levels, with complex geometries and varied equivalence ratios. This study thus focuses on experimental results obtained to characterise the CRZ formed under varied combustion conditions with different geometries and some variation of swirl number in a generic swirl burner. CRZ behaviour has similarities to the equivalent isothermal state, but is strongly dependent on equivalence ratio, with interesting effects occurring with a high-velocity fuel injector. Partial premixing and combustion cause more substantive changes to the CRZ than pure diffusive combustion. (orig.)

  18. Reactive Flow Control of Delta Wing Vortex (Postprint)

    Science.gov (United States)

    2006-08-01

    wing aircraft. A substantial amount of research has been dedicated to the control of aerodynamic flows using both passive and active control mechanisms...Passive vortex control devices such as vortex generators and winglets attach to the wing and require no energy input. Passive vortex control...leading edges is also effective for changing the aerodynamic characteristics of delta wings [2] [3]. Gutmark and Guillot [5] proposed controlling

  19. Evaluation of Gas Reburning and Low N0x Burners on a Wall Fired Boiler

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-07-01

    Under the U.S. Department of Energy's Clean Coal Technology Program (Round 3), a project was completed to demonstrate control of boiler NOX emissions and to a lesser degree, due to coal replacement, SO2 emissions. The project involved combining Gas Reburning with Low NOX Burners (GR-LNB) on a coal-fired electric utility boiler to determine if high levels of NO, reduction (70VO) could be achieved. Sponsors of the project included the U.S. Depatiment of Energy, the Gas Research Institute, Public Service Company of Colorado, Colorado Interstate Gas, Electric Power Research Institute, and the Energy and Environmental Research Corporation. The GR-LNB demonstration was petformed on Public Service Company of Colorado's (PSCO) Cherokee Unit #3, located in Denver, Colorado. This unit is a 172 MW~ wall-fired boiler that uses Colorado bituminous, low-sulfur coal. It had a baseline NO, emission level of 0.73 lb/1 OG Btu using conventional burners. Low NOX burners are designed to yield lower NOX emissions than conventional burners. However, the NOX control achieved with this technique is limited to 30-50Y0. Also, with LNBs, CO emissions can increase to above acceptable standards. Gas Reburning (GR) is designed to reduce NO, in the flue gas by staged fuel combustion. This technology involves the introduction of' natural gas into the hot furnace flue gas stream. When combined, GR and LNBs minimize NOX emissions and maintain acceptable levels of CO emissions. A comprehensive test program was completed, operating over a wide range of boiler conditions. Over 4,000 hours of operation were achieved, providing substantial data. Measurements were taken to quantify reductions in NOX emissions, the impact on boiler equipment and operability and factors influencing costs. The GR-LNB technology achieved good NO, emission reductions and the goals of the project were achieved. Although the performance of the low NOX burners (supplied by others) was less than expected, a NOX

  20. Design and construction of an air inductor burner

    International Nuclear Information System (INIS)

    Martinez, Camilo; Cardona, Mario; Arrieta, Andres Amell

    2001-01-01

    This article presents research results performed with the purpose of obtain design parameters, construction, and air inductor burner operation, which are used in industrial combustion systems, in several processes such as: metal fusion (fusion furnaces), fluids heating (immerse heating tubes), steam production (steam boiler), drying processes, etc. In order to achieve such objectives, a prototype with thermal power modulation from 6 to 52 kW, was built to be either operated with natural gas or with LPG. The burner was built taking in mind the know how (design procedure) developed according to theoretical schemes of different bibliographic references and knowledge of the research group in gas science and technology of the University of Antioquia. However, with such procedure only the burner mixer is dimensioned and five parameters must to be selected by the designer: burner thermal power, primary aeration ratio, counter pressure at combustion chamber, air pressure admission and gas fuel intended to use. For head design we took in mind research done before by the group of science and technology in gas research: Mono port and bar burner heads with their respective stabilization flame systems

  1. Flow-Control Unit For Nitrogen And Hydrogen Gases

    Science.gov (United States)

    Chang, B. J.; Novak, D. W.

    1990-01-01

    Gas-flow-control unit installed and removed as one piece replaces system that included nine separately serviced components. Unit controls and monitors flows of nitrogen and hydrogen gases. Designed for connection via fluid-interface manifold plate, reducing number of mechanical fluid-interface connections from 18 to 1. Unit provides increasing reliability, safety, and ease of maintenance, and for reducing weight, volume, and power consumption.

  2. Turbulent Flow Modification With Thermoacoustic Waves for Separation Control

    Science.gov (United States)

    2017-08-24

    respectively. At the outlet, the time-average flow is set to be the target state of the sponge zone. In this section, the effects of momentum thickness...Turbulent Flow Modification With Thermoacoustic Waves For Separation Control The views, opinions and/or findings contained in this report are those...currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. Florida State University Sponsored Research Administration 874

  3. Exhaust bypass flow control for exhaust heat recovery

    Science.gov (United States)

    Reynolds, Michael G.

    2015-09-22

    An exhaust system for an engine comprises an exhaust heat recovery apparatus configured to receive exhaust gas from the engine and comprises a first flow passage in fluid communication with the exhaust gas and a second flow passage in fluid communication with the exhaust gas. A heat exchanger/energy recovery unit is disposed in the second flow passage and has a working fluid circulating therethrough for exchange of heat from the exhaust gas to the working fluid. A control valve is disposed downstream of the first and the second flow passages in a low temperature region of the exhaust heat recovery apparatus to direct exhaust gas through the first flow passage or the second flow passage.

  4. Bluff Body Flow Control Using Dielectric Barrier Discharge Plasma Actuators

    Science.gov (United States)

    Thomas, Flint; Kozlov, Alexey

    2008-11-01

    The results of an experimental investigation involving the use of dielectric barrier discharge plasma actuators to control bluff body flow is presented. The motivation for the work is plasma landing gear noise control for commercial transport aircraft. For these flow control experiments, the cylinder in cross-flow is chosen for study since it represents a generic flow geometry that is similar in all essential aspects to a landing gear strut. The current work is aimed both at extending the plasma flow control concept to Reynolds numbers typical of landing approach and take-off and on the development of optimum plasma actuation strategies. The cylinder wake flow with and without actuation are documented in detail using particle image velocimetry (PIV) and constant temperature hot-wire anemometry. The experiments are performed over a Reynolds number range extending to ReD=10^5. Using either steady or unsteady plasma actuation, it is demonstrated that even at the highest Reynolds number Karman shedding is totally eliminated and turbulence levels in the wake decrease by more than 50%. By minimizing the unsteady flow separation from the cylinder and associated large-scale wake vorticity, the radiated aerodynamic noise is also reduced.

  5. Numerical investigation into premixed hydrogen combustion within two-stage porous media burner of 1 kW solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Yen Tzu-Hsiang; Chen Bao-Dong [Refining and Manufacturing Research Institute, CPC Corporation, Chia-Yi City 60036, Taiwan (China); Hong Wen-Tang; Tsai Yu-Ching; Wang Hung-Yu; Huang Cheng-Nan; Lee Chien-Hsiung [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546, Taiwan (China)

    2010-07-01

    Numerical simulations are performed to analyze the combustion of the anode off-gas / cathode off-gas mixture within the two-stage porous media burner of a 1 kW solid oxide fuel cell (SOFC) system. In performing the simulations, the anode gas is assumed to be hydrogen and the combustion of the gas mixture is modeled using a turbulent flow model. The validity of the numerical model is confirmed by comparing the simulation results for the flame barrier temperature and the porous media temperature with the corresponding experimental results. Simulations are then performed to investigate the effects of the hydrogen content and the burner geometry on the temperature distribution within the burner and the corresponding operational range. It is shown that the maximum flame temperature increases with an increasing hydrogen content. In addition, it is found that the burner has an operational range of 1.2--6.5 kW when assigned its default geometry settings (i.e. a length and diameter of 0.17 m and 0.06 m, respectively), but increases to 2--9 kW and 2.6--11.5 kW when the length and diameter are increased by a factor of 1.5, respectively. Finally, the operational range increases to 3.5--16.5 kW when both the diameter and the length of the burner are increased by a factor of 1.5.

  6. NASA GRC's High Pressure Burner Rig Facility and Materials Test Capabilities

    Science.gov (United States)

    Robinson, R. Craig

    1999-01-01

    The High Pressure Burner Rig (HPBR) at NASA Glenn Research Center is a high-velocity. pressurized combustion test rig used for high-temperature environmental durability studies of advanced materials and components. The facility burns jet fuel and air in controlled ratios, simulating combustion gas chemistries and temperatures that are realistic to those in gas turbine engines. In addition, the test section is capable of simulating the pressures and gas velocities representative of today's aircraft. The HPBR provides a relatively inexpensive. yet sophisticated means for researchers to study the high-temperature oxidation of advanced materials. The facility has the unique capability of operating under both fuel-lean and fuel-rich gas mixtures. using a fume incinerator to eliminate any harmful byproduct emissions (CO, H2S) of rich-burn operation. Test samples are easily accessible for ongoing inspection and documentation of weight change, thickness, cracking, and other metrics. Temperature measurement is available in the form of both thermocouples and optical pyrometery. and the facility is equipped with quartz windows for observation and video taping. Operating conditions include: (1) 1.0 kg/sec (2.0 lbm/sec) combustion and secondary cooling airflow capability: (2) Equivalence ratios of 0.5- 1.0 (lean) to 1.5-2.0 (rich), with typically 10% H2O vapor pressure: (3) Gas temperatures ranging 700-1650 C (1300-3000 F): (4) Test pressures ranging 4-12 atmospheres: (5) Gas flow velocities ranging 10-30 m/s (50-100) ft/sec.: and (6) Cyclic and steady-state exposure capabilities. The facility has historically been used to test coupon-size materials. including metals and ceramics. However complex-shaped components have also been tested including cylinders, airfoils, and film-cooled end walls. The facility has also been used to develop thin-film temperature measurement sensors.

  7. A Numerical Proof of Concept for Thermal Flow Control

    Directory of Open Access Journals (Sweden)

    V. Dragan

    2017-02-01

    Full Text Available In this paper computational fluid dynamics is used to provide a proof of concept for controlled flow separation using thermal wall interactions with the velocity boundary layer. A 3D case study is presented, using a transition modeling Shear Stress Transport turbulence model. The highly loaded single slot flap airfoil was chosen to be representative for a light aircraft and the flow conditions were modeled after a typical landing speed. In the baseline case, adiabatic walls were considered while in the separation control case, the top surface of the flaps was heated to 500 K. This heating lead to flow separation on the flaps and a significant alteration of the flow pattern across all the elements of the wing. The findings indicate that this control method has potential, with implications in both aeronautical as well as sports and civil engineering applications.

  8. Flow and Noise Control: Review and Assessment of Future Directions

    Science.gov (United States)

    Thomas, Russell H.; Choudhari, Meelan M.; Joslin, Ronald D.

    2002-01-01

    Technologies for developing radically new aerovehicles that would combine quantum leaps in cost, safety, and performance benefits with environmental friendliness have appeared on the horizon. This report provides both an assessment of the current state-of-the-art in flow and noise control and a vision for the potential gains to be made, in terms of performance benefit for civil and military aircraft and a unique potential for noise reduction, via future advances in flow and noise technologies. This report outlines specific areas of research that will enable the breakthroughs necessary to bring this vision to reality. Recent developments in many topics within flow and noise control are reviewed. The flow control overview provides succinct summaries of various approaches for drag reduction and improved maneuvering. Both exterior and interior noise problems are examined, including dominant noise sources, physics of noise generation and propagation, and both established and proposed concepts for noise reduction. Synergy between flow and noise control is a focus and, more broadly, the need to pursue research in a more concurrent approach involving multiple disciplines. Also discussed are emerging technologies such as nanotechnology that may have a significant impact on the progress of flow and noise control.

  9. Dependence of flame length on cross sections of burners

    Energy Technology Data Exchange (ETDEWEB)

    Hackeschmidt, M.

    1983-06-01

    This article analyzes the relation between the shape of burner muzzle and the resulting flame jet in a combustion chamber. Geometrical shapes of burner muzzles, either square, circular or triangular are compared as well as proportions of flame dimensions. A formula for calculating flame lengths is derived, for which the mathematical value 'contact profile radius' for burner muzzle shape is introduced. The formula for calculating flame lengths allows a partial replacement of the empirical flame mixing factor according to N.Q. Toai, 1981. The geometrical analysis does not include thermodynamic and reaction kinetic studies, which may be necessary for evaluating heterogenous (coal dust) combustion flames with longer burning time. (12 refs.)

  10. Active Flow Control and Global Stability Analysis of Separated Flow Over a NACA 0012 Airfoil

    Science.gov (United States)

    Munday, Phillip M.

    The objective of this computational study is to examine and quantify the influence of fundamental flow control inputs in suppressing flow separation over a canonical airfoil. Most flow control studies to this date have relied on the development of actuator technology, and described the control input based on specific actuators. Taking advantage of a computational framework, we generalize the inputs to fundamental perturbations without restricting inputs to a particular actuator. Utilizing this viewpoint, generalized control inputs aim to aid in the quantification and support the design of separation control techniques. This study in particular independently introduces wall-normal momentum and angular momentum to the separated flow using swirling jets through model boundary conditions. The response of the flow field and the surface vorticity fluxes to various combinations of actuation inputs are examined in detail. By closely studying different variables, the influence of the wall-normal and angular momentum injections on separated flow is identified. As an example, open-loop control of fully separated, incompressible flow over a NACA 0012 airfoil at alpha = 6° and 9° with Re = 23,000 is examined with large-eddy simulations. For the shallow angle of attack alpha = 6°, the small recirculation region is primarily affected by wall-normal momentum injection. For a larger separation region at alpha = 9°, it is observed that the addition of angular momentum input to wall-normal momentum injection enhances the suppression of flow separation. Reducing the size of the separated flow region significantly impacts the forces, and in particular reduces drag and increases lift on the airfoil. It was found that the influence of flow control on the small recirculation region (alpha = 6°) can be sufficiently quantified with the traditional coefficient of momentum. At alpha = 9°, the effects of wall-normal and angular momentum inputs are captured by modifying the standard

  11. Measurements of the concentration of major chemical species in the flame of a test burner with a air swirling system; Mesures de concentration d`especes chimiques majoritaires dans la flamme d`un bruleur modele avec mise en rotation de l`air

    Energy Technology Data Exchange (ETDEWEB)

    Albert, St. [Gaz de France (GDF), 93 - La Plaine-Saint-Denis (France); Most, J.M.; Poireault, B. [Centre National de la Recherche Scientifique (CNRS), 86 - Poitiers (France)

    1996-12-31

    The study of combustion in industrial burners remains difficult because of the complexity of the equipments used: materials geometry, tri-dimensional flows etc.. The phenomena that control the combustion in a gas burner with a swirl air system has been studied thanks to a collaboration between the Direction of Research of Gaz de France (GdF) and the Laboratory for Combustion and Detonation Research (LCD) of the French National Centre of Scientific Research (CNRS). The burner used is developed by the LCD and the measurements of stable chemical species were performed by the CERSTA centre of GdF. These series of tests, performed in confined environment, have permitted to identify some of the parameters that influence combustion chemistry. Mapping of chemical species allows to distinguish 5 zones of flame development and also the zones of nitrogen oxides formation. Methane is rapidly centrifuged a few millimeters above the injection pipe and centrifuged with rotating combustion air. Carbon monoxide occurs immediately in the central recirculation zone which is weakly reactive (no oxygen and no methane). Oxygen content increases downflow from this area and carbon dioxide reaches its concentration maxima. CO formation decreases when the swirl number increases and CO{sub 2} formation occurs earlier. On the contrary, the emissions of CO and CH{sub 4} do not depend on the swirl value and the NO{sub x} values are only slightly dependent on this value. (J.S.)

  12. Process development report: 0.40-m primary burner system

    International Nuclear Information System (INIS)

    Young, D.T.

    1978-04-01

    Fluidized bed combustion is required in reprocessing the graphite-based fuel elements from high-temperature gas-cooled reactor (HTGR) cores. This burning process requires combustion of beds containing both large particles and very dense particles, and also of fine graphite particles which elutriate from the bed. This report documents the successful long-term operation of the 0.40-m primary burner in burning crushed fuel elements. The 0.40-m system operation is followed from its first short heatup test in September 1976 to a > 40-h burning campaign that processed 20 LHTGR blocks in September 1977. The 0.40-m perforated conical gas distributor, scaled up from the 0.20-m primary burner, has proven reliable in safely burning even the largest, densest adhered graphite/fuel particle clusters originating from the crushing of loaded fuel elements. Such clusters had never been fed to the 0.20-m system. Efficient combustion of graphite fines using the pressurized recycle technique was demonstrated throughout the long-duration operation required to reduce a high carbon fresh feed bed to a low carbon particle bed. Again, such operation had never been completed on the 0.20-m system from which the 0.40-m burner was scaled. The successful completion of the tests was due, in part, to implementation of significant equipment revisions which were suggested by both the initial 0.40-m system tests and by results of ongoing development work on the 0.2-m primary burner. These revisions included additional penetrations in the burner tube side-wall for above-bed fines recycle, replacement and deletion of several metal bellows with bellows of more reliable design, and improvements in designs for burner alignment and feeder mechanisms. 76 figures, 8 tables

  13. Global nuclear material flow/control model

    International Nuclear Information System (INIS)

    Dreicer, J.S.; Rutherford, D.S.; Fasel, P.K.; Riese, J.M.

    1997-01-01

    This is the final report of a two-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The nuclear danger can be reduced by a system for global management, protection, control, and accounting as part of an international regime for nuclear materials. The development of an international fissile material management and control regime requires conceptual research supported by an analytical and modeling tool which treats the nuclear fuel cycle as a complete system. The prototype model developed visually represents the fundamental data, information, and capabilities related to the nuclear fuel cycle in a framework supportive of national or an international perspective. This includes an assessment of the global distribution of military and civilian fissile material inventories, a representation of the proliferation pertinent physical processes, facility specific geographic identification, and the capability to estimate resource requirements for the management and control of nuclear material. The model establishes the foundation for evaluating the global production, disposition, and safeguards and security requirements for fissile nuclear material and supports the development of other pertinent algorithmic capabilities necessary to undertake further global nuclear material related studies

  14. Control of a Quadcopter Aerial Robot Using Optic Flow Sensing

    Science.gov (United States)

    Hurd, Michael Brandon

    This thesis focuses on the motion control of a custom-built quadcopter aerial robot using optic flow sensing. Optic flow sensing is a vision-based approach that can provide a robot the ability to fly in global positioning system (GPS) denied environments, such as indoor environments. In this work, optic flow sensors are used to stabilize the motion of quadcopter robot, where an optic flow algorithm is applied to provide odometry measurements to the quadcopter's central processing unit to monitor the flight heading. The optic-flow sensor and algorithm are capable of gathering and processing the images at 250 frames/sec, and the sensor package weighs 2.5 g and has a footprint of 6 cm2 in area. The odometry value from the optic flow sensor is then used a feedback information in a simple proportional-integral-derivative (PID) controller on the quadcopter. Experimental results are presented to demonstrate the effectiveness of using optic flow for controlling the motion of the quadcopter aerial robot. The technique presented herein can be applied to different types of aerial robotic systems or unmanned aerial vehicles (UAVs), as well as unmanned ground vehicles (UGV).

  15. Behaviors of tribrachial edge flames and their interactions in a triple-port burner

    KAUST Repository

    Yamamoto, Kazuhiro

    2015-05-01

    In a triple-port burner, various non-premixed flames have been observed previously. Especially for the case with two lifted flames, such configuration could be suitable in studying interaction between two tribrachial flames. In the present study, the flame characteristics have been investigated numerically by adopting a reduced kinetic mechanism in the triple-port burner. Four different types of flame configurations, including two attached flames, inner lifted/outer attached flames, inner attached/outer lifted flames, and twin lifted flames, were successfully simulated depending on the flow conditions. The representative edge propagation speed of a single lifted flame or an upstream lifted flame in the case of twin lifted flames increased as the liftoff height became higher. In the twin lifted flames, the inner lifted flame was affected appreciably when the other flame was located further upstream such that the lifted flame located further downstream encountered the axial velocity acceleration induced by the gas expansion from the lifted flame located upstream, while thermal effects were not observed since the temperature of the incoming flow toward the lifted flame was not affected. A unique flip-flop behavior between the inner and outer flames, observed experimentally previously, was successfully captured in the simulation such that the inner lifted flame became attached to the nozzle as the liftoff height of the outer lifted flame grew higher with an increase in the outer air velocity.

  16. Incineration of ion exchange resins using concentric burners

    International Nuclear Information System (INIS)

    Fukasawa, T.; Chino, K.; Kawamura, F.; Kuriyama, O.; Yusa, H.

    1985-01-01

    A new incineration method, using concentric burners, is studied to reduce the volume of spent ion exchange resins generated from nuclear power plants. Resins are ejected into the center of a propane-oxygen flame and burned within it. The flame length is theoretically evaluated by the diffusion-dominant model. By reforming the burner shape, flame length can be reduced by one-half. The decomposition ratio decreases with larger resin diameters due to the loss of unburned resin from the flame. A flame guide tube is adapted to increase resin holding time in the flame, which improves the decomposition ratio to over 98 wt%

  17. BURNER RIG TESTING OF A500 C/SiC

    Science.gov (United States)

    2018-03-17

    AFRL-RX-WP-TR-2018-0071 BURNER RIG TESTING OF A500® C /SiC Larry P. Zawada Universal Technology Corporation Jennifer Pierce UDRI...TITLE AND SUBTITLE BURNER RIG TESTING OF A500® C /SiC 5a. CONTRACT NUMBER In-House 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6...test program characterized the durability behavior of A500® C /SiC ceramic matrix composite material at room and elevated temperature. Specimens were

  18. Synthetic perspective optical flow: Influence on pilot control tasks

    Science.gov (United States)

    Bennett, C. Thomas; Johnson, Walter W.; Perrone, John A.; Phatak, Anil V.

    1989-01-01

    One approach used to better understand the impact of visual flow on control tasks has been to use synthetic perspective flow patterns. Such patterns are the result of apparent motion across a grid or random dot display. Unfortunately, the optical flow so generated is based on a subset of the flow information that exists in the real world. The danger is that the resulting optical motions may not generate the visual flow patterns useful for actual flight control. Researchers conducted a series of studies directed at understanding the characteristics of synthetic perspective flow that support various pilot tasks. In the first of these, they examined the control of altitude over various perspective grid textures (Johnson et al., 1987). Another set of studies was directed at studying the head tracking of targets moving in a 3-D coordinate system. These studies, parametric in nature, utilized both impoverished and complex virtual worlds represented by simple perspective grids at one extreme, and computer-generated terrain at the other. These studies are part of an applied visual research program directed at understanding the design principles required for the development of instruments displaying spatial orientation information. The experiments also highlight the need for modeling the impact of spatial displays on pilot control tasks.

  19. A note on supersonic flow control with nanosecond plasma actuator

    Science.gov (United States)

    Zheng, J. G.; Cui, Y. D.; Li, J.; Khoo, B. C.

    2018-04-01

    A concept study on supersonic flow control using nanosecond pulsed plasma actuator is conducted by means of numerical simulation. The nanosecond plasma discharge is characterized by the generation of a micro-shock wave in ambient air and a residual heat in the discharge volume arising from the rapid heating of near-surface gas by the quick discharge. The residual heat has been found to be essential for the flow separation control over aerodynamic bodies like airfoil and backward-facing step. In this study, novel experiment is designed to utilize the other flow feature from discharge, i.e., instant shock wave, to control supersonic flow through shock-shock interaction. Both bow shock in front of a blunt body and attached shock anchored at the tip of supersonic projectile are manipulated via the discharged-induced shock wave in an appropriate manner. It is observed that drag on the blunt body is reduced appreciably. Meanwhile, a lateral force on sharp-edged projectile is produced, which can steer the body and give it an effective angle of attack. This opens a promising possibility for extending the applicability of this flow control technique in supersonic flow regime.

  20. Multilevel flow modelling of process plant for diagnosis and control

    International Nuclear Information System (INIS)

    Lind, M.

    1982-08-01

    The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as basic for design of control strategies and for the allocation of control tasks to the computer and the plant operator. (author)

  1. Multilevel Flow Modelling of Process Plant for Diagnosis and Control

    DEFF Research Database (Denmark)

    Lind, Morten

    1982-01-01

    The paper describes the multilevel flow modelling methodology which can be used to construct functional models of energy and material processing systems. The models describe mass and energy flow topology on different levels of abstraction and represent the hierarchical functional structure...... of complex systems. A model of a nuclear power plant (PWR) is presented in the paper for illustration. Due to the consistency of the method, multilevel flow models provide specifications of plant goals and functions and may be used as a basis for design of computer-based support systems for the plant...... operator. Plant control requirements can be derived from the models and due to independence of the actual controller implementation the method may be used as a basis for design of control strategies and for the allocation of control tasks to the computer and the plant operator....

  2. Liquid metal flow control by DC electromagnetic pumps

    International Nuclear Information System (INIS)

    Borges, Eduardo Madeira; Braz Filho, Francisco Antonio; Guimaraes, Lamartine Nogueira Frutuoso

    2006-01-01

    The cooling system of high-density thermal power requires fluids of high thermal conductivity, such as liquid metals. Electromagnetic pumps can be used to liquid metal fluid flow control in cooling circuits. The operation of electromagnetic pumps used to flow control is based on Lorentz force. This force can be achieved by magnetic field and electric current interaction, controlled by external independent power supplies. This work presents the electromagnetic pump operational principles, the IEAv development scheme and the BEMC-1 simulation code. The theoretical results of BEMC-1 simulation are compared to electromagnetic pump operation experimental data, validating the BEMC-1 code. This code is used to evaluate the DC electromagnetic pump performance applied to Mercury flow control and others liquid metal such as Sodium, Lead and Bismuth, used in nuclear fast reactors. (author)

  3. The acoustic response of burner-stabilised flat flames : a two-dimensional numerical analysis

    NARCIS (Netherlands)

    Rook, R.; Goey, de L.P.H.

    2003-01-01

    The response of burner-stabilized flat flames to acoustic perturbations is studied numerically. So far, one-dimensional models have been used to study this system. However, in most practical surface burners, the scale of the perforations in the burner plate is of the order of the flame thickness.

  4. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS VOLUME III. FIELD EVALUATIONS

    Science.gov (United States)

    The report gives results of field tests conducted to determine the emission characteristics of a Babcock and Wilcox Circular burner and Dual Register burner (DRB). The field tests were performed at two utility boilers, generally comparable in design and size except for the burner...

  5. Predictive Flow Control to Minimize Convective Time Delays

    Science.gov (United States)

    2013-08-19

    external flows around air vehicles or ground based systems such as bridges and buildings, internal flows in pipes and propulsion systems, acoustical...3437, 1977. [4] Bridges , D. H., "The Asymmetric Vortex Wake Problem - Asking the Right Question," A/AA Paper 2006-3553, 2006. [5) Deng, X. Y., Tian, W...Aircraft, Vol. 42, No. 2, 2003, pp. 42~23. [8] Darden, L. and Komerath, N., "Forebody Vortex Control at High Incidence using a Moveable Nose Stagnation

  6. Steady State Stokes Flow Interpolation for Fluid Control

    DEFF Research Database (Denmark)

    Bhatacharya, Haimasree; Nielsen, Michael Bang; Bridson, Robert

    2012-01-01

    — suffer from a common problem. They fail to capture the rotational components of the velocity field, although extrapolation in the normal direction does consider the tangential component. We address this problem by casting the interpolation as a steady state Stokes flow. This type of flow captures......Fluid control methods often require surface velocities interpolated throughout the interior of a shape to use the velocity as a feedback force or as a boundary condition. Prior methods for interpolation in computer graphics — velocity extrapolation in the normal direction and potential flow...

  7. Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

    Science.gov (United States)

    McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

    2011-01-01

    Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

  8. Gaseous emissions from burning diesel, crude and prime bleachable summer yellow cottonseed oil in a burner for drying seedcotton

    International Nuclear Information System (INIS)

    Holt, G.A.; Hooker, J.D.

    2004-01-01

    Cottonseed oil has been used as a fuel source either as a blend with diesel in varying proportions or undiluted (100 %) in numerous studies evaluating its potential use in internal combustion engines. However, limited research is available on the use of cottonseed oil as a fuel source in a multi-fueled burner similar to those used by cottonseed oil mills and cotton gins in their drying operations. The purpose of this study was to evaluate emissions from five fuel oil treatments while firing a multi-fueled burner in a setup similar to those used for drying operations of both cottonseed oil mills and cotton gins. For each treatment, gaseous emissions were measured while firing the burner at three fuel flow rates. The five fuel oil treatments evaluated were: (1) No.2 diesel at 28.3 deg C, (2) prime bleachable summer yellow (PBSY) cottonseed oil at 28.3 deg C (PBSY-28), (3) crude cottonseed oil at 28.3 deg C (Crude-28), (4) PBSY at 60 deg C (PBSY-60), and (5) crude at 60 deg C (Crude-60). Results indicate that PBSY treatments had the lowest overall emissions of all treatments. The other treatments varied in emission rates based on treatment and fuel flow rate. Preheating the oil to 60 deg C resulted in higher NO x emissions but displayed varying results in regards to CO. The CO emissions for the crude treatments were relatively unaffected by the 60 deg C preheat temperature whereas the preheated PBSY treatments demonstrated lower CO emissions. Overall, both cottonseed oils performed well in the multi-fueled burner and displayed a promising potential as an alternative fuel source for cottonseed oil mills and cotton gins in their drying operations. (Author)

  9. Temperature-gated thermal rectifier for active heat flow control.

    Science.gov (United States)

    Zhu, Jia; Hippalgaonkar, Kedar; Shen, Sheng; Wang, Kevin; Abate, Yohannes; Lee, Sangwook; Wu, Junqiao; Yin, Xiaobo; Majumdar, Arun; Zhang, Xiang

    2014-08-13

    Active heat flow control is essential for broad applications of heating, cooling, and energy conversion. Like electronic devices developed for the control of electric power, it is very desirable to develop advanced all-thermal solid-state devices that actively control heat flow without consuming other forms of energy. Here we demonstrate temperature-gated thermal rectification using vanadium dioxide beams in which the environmental temperature actively modulates asymmetric heat flow. In this three terminal device, there are two switchable states, which can be regulated by global heating. In the "Rectifier" state, we observe up to 28% thermal rectification. In the "Resistor" state, the thermal rectification is significantly suppressed (Rectifier state. This temperature-gated rectifier can have substantial implications ranging from autonomous thermal management of heating and cooling systems to efficient thermal energy conversion and storage.

  10. Nitrogen oxide formation as a function of the shape of the flame in an experimental gas burner. Stikstofoxidenvorming als functie van de vlamvorm bij experimentele gasbrander

    Energy Technology Data Exchange (ETDEWEB)

    Hulshof, H J.M.; Thus, A W

    1992-01-01

    One of the options to reduce the emission of NO[sub x] from gas-fired or coal-fired power plants is to develop new burners or to improve the control of existing burners. The purpose of this investigation is to develop a measuring method to control the combustion process in each burner of a gas-fired or coal-fired power plant concerning NO[sub x]-emission, a constant energy production and stability of the combustion. A passive spectroscopic measuring method was developed, in which use is made of the light, emitted by the flame. Based on the measured values the NO[sub x]-emissions and the shape of the flame were correlated. From the correlations it appears that flame shape and NO[sub x]-emissions correspond quite well

  11. Process development report: 0.20-m primary burner system

    International Nuclear Information System (INIS)

    Rickman, W.S.

    1978-09-01

    HTGR reprocessing consists of crushing the spent fuel elements to a size suitable for burning in a fluidized bed to remove excess graphite, separating the fissile and fertile particles, crushing and burning the SiC-coated fuel particles to remove the remainder of the carbon, dissolution and separation of the particles from insoluble materials, and solvent extraction separation of the dissolved uranium and thorium. Burning the crushed fuel elements is accomplished in a primary burner. This is a batch-continuous, fluidized-bed process utilizing above-bed gravity fines recycle. In gas-solid separation, a combination of a cyclone and porous metal filters is used. This report documents operational tests performed on a 0.20-m primary burner using crushed fuel representative of both Fort St. Vrain and large high-temperature gas-cooled reactor cores. The burner was reconstructed to a gravity fines recycle mode prior to beginning these tests. Results of two separate and successful 48-hour burner runs and several short-term runs have indicated the operability of this concept. Recommendations are made for future work

  12. 40 CFR 266.102 - Permit standards for burners.

    Science.gov (United States)

    2010-07-01

    ... or industrial furnace downstream of the combustion zone and prior to release of stack gases to the... MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.102 Permit standards for burners. (a) Applicability—(1) General. Owners and operators of boilers and industrial furnaces...

  13. The generation of resonant turbulence for a premixed burner

    NARCIS (Netherlands)

    Verbeek, Antonie Alex; Pos, R.C.; Stoffels, Genie G.M.; Geurts, Bernardus J.; van der Meer, Theodorus H.

    2012-01-01

    Is it possible to optimize the turbulent combustion of a low swirl burner by using resonance in turbulence? To that end an active grid is constructed that consists of two perforated disks of which one is rotating, creating a system of pulsating jets, which in the end can be used as a central

  14. The generation of resonant turbulence for a premixed burner

    NARCIS (Netherlands)

    Verbeek, Antonie Alex; Pos, R.C.; Stoffels, Genie G.M.; Geurts, Bernardus J.; van der Meer, Th.H.

    Is it possible to optimize the turbulent combustion of a low swirl burner by using resonance in turbu- lence? To that end an active grid is constructed that consists of two perforated disks of which one is rotat- ing, creating a system of pulsating jets, which in the end can be used as a central

  15. 300 MWe Burner Core Design with two Enrichment Zoning

    International Nuclear Information System (INIS)

    Song, Hoon; Kim, Sang Ji; Kim, Yeong Il

    2008-01-01

    KAERI has been developing the KALIMER-600 core design with a breakeven fissile conversion ratio. The core is loaded with a ternary metallic fuel (TRU-U-10Zr), and the breakeven characteristics are achieved without any blanket assembly. As an alternative plan, a KALIMER-600 burner core design has been also performed. In the early stage of the development of a fast reactor, the main purpose is an economical use of a uranium resource but nowadays in addition to the maximum utilization of a uranium resource, the burning of a high level radioactive waste is taken as an additional interest for the harmony of the environment. In way of constructing the commercial size reactor which has the power level ranging from 800 MWe to 1600 MWe, the demonstration reactor which has the power level ranging from 200 MWe to 600 MWe was usually constructed for the midterm stage to commercial size reactor. In this paper, a 300 MWe burner core design was performed with purpose of demonstration reactor for KALIMER-600 burner of 600 MWe. As a means to flatten the power distribution, instead of a single fuel enrichment scheme adapted in design of KALIMER-600 burner, the 2 enrichment zoning approach was adapted

  16. Effect of cycled combustion ageing on a cordierite burner plate

    International Nuclear Information System (INIS)

    Garcia, Eugenio; Gancedo, J. Ramon; Gracia, Mercedes

    2010-01-01

    A combination of 57 Fe-Moessbauer spectroscopy and X-ray Powder Diffraction analysis has been employed to study modifications in chemical and mechanical stability occurring in a cordierite burner aged under combustion conditions which simulate the working of domestic boilers. Moessbauer study shows that Fe is distributed into the structural sites of the cordierite lattice as Fe 2+ and Fe 3+ ions located mostly at octahedral sites. Ferric oxide impurities, mainly hematite, are also present in the starting cordierite material accounting for ≅40% of the total iron phases. From Moessbauer and X-ray diffraction data it can be deduced that, under the combustion conditions used, new crystalline phases were formed, some of the substitutional Fe 3+ ions existing in the cordierite lattice were reduced to Fe 2+ , and ferric oxides underwent a sintering process which results in hematite with higher particle size. All these findings were detected in the burner zone located in the proximity of the flame and were related to possible chemical reactions which might explain the observed deterioration of the burner material. Research Highlights: →Depth profile analyses used as a probe to understand changes in refractory structure. →All changes take place in the uppermost surface of the burner, close to the flame. →Reduction to Fe 2+ of substitutional Fe 3+ ions and partial cordierite decomposition. →Heating-cooling cycling induces a sintering of the existing iron oxide particles. →Chemical changes can explain the alterations observed in the material microstructure.

  17. Application of Shark Skin Flow Control Techniques to Airflow

    Science.gov (United States)

    Morris, Jackson Alexander

    Due to millions of years of evolution, sharks have evolved to become quick and efficient ocean apex predators. Shark skin is made up of millions of microscopic scales, or denticles, that are approximately 0.2 mm in size. Scales located on the shark's body where separation control is paramount (such as behind the gills or the trailing edge of the pectoral fin) are capable of bristling. These scales are hypothesized to act as a flow control mechanism capable of being passively actuated by reversed flow. It is believed that shark scales are strategically sized to interact with the lower 5% of a boundary layer, where reversed flow occurs at the onset of boundary layer separation. Previous research has shown shark skin to be capable of controlling separation in water. This thesis aims to investigate the same passive flow control techniques in air. To investigate this phenomenon, several sets of microflaps were designed and manufactured with a 3D printer. The microflaps were designed in both 2D (rectangular) and 3D (mirroring shark scale geometry) variants. These microflaps were placed in a low-speed wind tunnel in the lower 5% of the boundary layer. Solid fences and a flat plate diffuser with suction were placed in the tunnel to create different separated flow regions. A hot film probe was used to measure velocity magnitude in the streamwise plane of the separated regions. The results showed that low-speed airflow is capable of bristling objects in the boundary layer. When placed in a region of reverse flow, the microflaps were passively actuated. Microflaps fluctuated between bristled and flat states in reverse flow regions located close to the reattachment zone.

  18. A Calculus for Control Flow Analysis of Security Protocols

    DEFF Research Database (Denmark)

    Buchholtz, Mikael; Nielson, Hanne Riis; Nielson, Flemming

    2004-01-01

    The design of a process calculus for anaysing security protocols is governed by three factors: how to express the security protocol in a precise and faithful manner, how to accommodate the variety of attack scenarios, and how to utilise the strengths (and limit the weaknesses) of the underlying...... analysis methodology. We pursue an analysis methodology based on control flow analysis in flow logic style and we have previously shown its ability to analyse a variety of security protocols. This paper develops a calculus, LysaNS that allows for much greater control and clarity in the description...

  19. Objective function choice for control of a thermocapillary flow using an adjoint-based control strategy

    International Nuclear Information System (INIS)

    Muldoon, Frank H.; Kuhlmann, Hendrik C.

    2015-01-01

    Highlights: • Suppression of oscillations in a thermocapillary flow is addressed by optimization. • The gradient of the objective function is obtained by solving the adjoint equations. • The issue of choosing an objective function is investigated. - Abstract: The problem of suppressing flow oscillations in a thermocapillary flow is addressed using a gradient-based control strategy. The physical problem addressed is the “open boat” process of crystal growth, the flow in which is driven by thermocapillary and buoyancy effects. The problem is modeled by the two-dimensional unsteady incompressible Navier–Stokes and energy equations under the Boussinesq approximation. The goal of the control is to suppress flow oscillations which arise when the driving forces are such that the flow becomes unsteady. The control is a spatially and temporally varying temperature gradient boundary condition at the free surface. The control which minimizes the flow oscillations is found using a conjugate gradient method, where the gradient of the objective function with respect to the control variables is obtained from solving a set of adjoint equations. The issue of choosing an objective function that can be both optimized in a computationally efficient manner and optimization of which provides control that damps the flow oscillations is investigated. Almost complete suppression of the flow oscillations is obtained for certain choices of the objective function.

  20. The effectiveness of recirculating flue gasses on a gas-fuel oil boiler unit with hearth burners

    Energy Technology Data Exchange (ETDEWEB)

    Eremeev, V V; Kovalenko, A L; Kozlov, V G

    1981-01-01

    The results of investigating the effect of recirculating flue gasses on a TP-87 boiler (D = 420 tons per hour, 14 MPa, 560 C) with a hearth composition of four gas-fuel oil burners are presented. The heat-release rate of the volume of the furnace is 136 Kw per m/sup 3/; that if a cross section of the combustion chamber is 3.2 MW/m/sup 2/. The hot air temperature is 420 C. The tests were carried out during the combustion of M-100 petroleum oil which has a moisture content of 3 / 4% and a sulfur content of 2.4%. The pressure of the oil against the mechanical sprayers is 2.9-3.0 MPa at the rated load; the temperature is 125-130 C. The recirculation of the flue gasses was organized in order to expand the regulatory stress range and decrease the discharge of nitric oxides into the atmosphere. Moreover, flue gasses with a temperature of 330-370/sup 0/C were removed from a first-degree BE gas conduit, and, using two BGD-15.5 type exhaust fans, were fed into the annular channels around the burners. The calculated velocity of the gasses at the output of the burner is equal to 35 M/s; the air velocity is 64 M/s. It is shown that the TP-87 furnace--with fuel oil hearth burners and recirculation to obtain flue gasses into independent burner ducts--makes it possible to obtain a useful stress range during almost complete fuel oil combustion with minimal air exceses by maintaining the calculated temperature of the superheated vapor. Recirculating flue gasses in a duct around the burners constitutes an effective means of decreasing the discharge of nitric oxides, and of decreasing local heat stress on the screens. However, increasing the recirculation coefficient to 0.17 causes a 0.35% increase in the loss of heat with the departing gasses (the temperature of which increases by 7 C), and a 0.15% decrease in the heat flow rate for SN, which leads to an overall drop of approx. 0.5% in the efficiency coefficient of the boiler.

  1. Topographic control of oceanic flows in deep passages and straits

    Science.gov (United States)

    Whitehead, J. A.

    1998-08-01

    Saddle points between neighboring deep ocean basins are the sites of unidirectional flow from one basin to the next, depending on the source of bottom water. Flow in these sites appears to be topographically controlled so the interface between the bottom water and the water above adjusts itself to permit bottom water flow from the basin that contains a source of bottom water into the next. Examples in the Atlantic include flow in the Romanche Fracture Zone, the Vema Channel, the Ceara Abyssal Plain, the Anegada-Jungfern passage, and the Discovery Gap, but there are many more. Theoretical predictions of volume flux using a method that requires only conductivity-temperature-depth data archives and detailed knowledge of bathymetry near the saddle point are compared with volume flux estimates using current meters and/or geostrophic estimates for seven cases. The ratio of prediction to volume flux estimate ranges from 1.0 to 2.7. Some ocean straits that separate adjacent seas are also found to critically control bidirectional flows between basins. Theory of the influence of rotation on such critical flows is reviewed. Predictions of volume flux in eight cases are compared with ocean estimates of volume flux from traditional methods.

  2. Structural integrated sensor and actuator systems for active flow control

    Science.gov (United States)

    Behr, Christian; Schwerter, Martin; Leester-Schädel, Monika; Wierach, Peter; Dietzel, Andreas; Sinapius, Michael

    2016-04-01

    An adaptive flow separation control system is designed and implemented as an essential part of a novel high-lift device for future aircraft. The system consists of MEMS pressure sensors to determine the flow conditions and adaptive lips to regulate the mass flow and the velocity of a wall near stream over the internally blown Coanda flap. By the oscillating lip the mass flow in the blowing slot changes dynamically, consequently the momentum exchange of the boundary layer over a high lift flap required mass flow can be reduced. These new compact and highly integrated systems provide a real-time monitoring and manipulation of the flow conditions. In this context the integration of pressure sensors into flow sensing airfoils of composite material is investigated. Mechanical and electrical properties of the integrated sensors are investigated under mechanical loads during tensile tests. The sensors contain a reference pressure chamber isolated to the ambient by a deformable membrane with integrated piezoresistors connected as a Wheatstone bridge, which outputs voltage signals depending on the ambient pressure. The composite material in which the sensors are embedded consists of 22 individual layers of unidirectional glass fiber reinforced plastic (GFRP) prepreg. The results of the experiments are used for adapting the design of the sensors and the layout of the laminate to ensure an optimized flux of force in highly loaded structures primarily for future aeronautical applications. It can be shown that the pressure sensor withstands the embedding process into fiber composites with full functional capability and predictable behavior under stress.

  3. Flow Characteristics of Ground Vehicle Wake and Its Response to Flow Control

    Science.gov (United States)

    Sellappan, Prabu; McNally, Jonathan; Alvi, Farrukh

    2017-11-01

    Air pollution, fuel shortages, and cost savings are some of the many incentives for improving the aerodynamics of vehicles. Reducing wake-induced aerodynamic drag, which is dependent on flow topology, on modern passenger vehicles is important for improving fuel consumption rates which directly affect the environment. In this research, an active flow control technique is applied on a generic ground vehicle, a 25°Ahmed model, to investigate its effect on the flow topology in the near-wake. The flow field of this canonical bluff body is extremely rich, with complex and unsteady flow features such as trailing wake vortices and c-pillar vortices. The spatio-temporal response of these flow features to the application of steady microjet actuators is investigated. The responses are characterized independently through time-resolved and volumetric velocity field measurements. The accuracy and cost of volumetric measurements in this complex flow field through Stereoscopic- and Tomographic- Particle Image Velocimetry (PIV) will also be commented upon. National Science Foundation PIRE Program.

  4. Impact of fuel quality and burner capacity on the performance of wood pellet stove

    Directory of Open Access Journals (Sweden)

    Petrović-Bećirović Sanja B.

    2015-01-01

    Full Text Available Pellet stoves may play an important role in Serbia in the future when fossil fuel fired conventional heating appliances are replaced by more efficient and environmentally friendly devices. Experimental investigation was conducted in order to examine the influence of wood pellet quality, as well as burner capacity (6, 8 and 10 kW, used in the same stove configuration, on the performance of pellet stove with declared nameplate capacity of 8 kW. The results obtained showed that in case of nominal load and combustion of pellets recommended by the stove manufacturer, stove efficiency of 80.03% was achieved. The use of lower quality pellet caused additional 1.13 kW reduction in heat output in case of nominal load and 0.63 kW in case of reduced load. This was attributed to less favourable properties and lower bulk and particle density of lower quality pellet. The use of different burner capacity has shown to have little effect on heat output and efficiency of the stove when pre-set values in the control system of the stove were not altered. It is concluded that replacement of the burner only is not sufficient to increase/decrease the declared capacity of the same stove configuration, meaning that additional measures are necessary. These measures include a new set up of the stove control system, which needs to be properly adjusted for each alteration in stove configuration. Without the adjustment mentioned, declared capacity of the stove cannot be altered, while its CO emission shall be considerably increased.

  5. Verification of the karst flow model under laboratory controlled conditions

    Science.gov (United States)

    Gotovac, Hrvoje; Andric, Ivo; Malenica, Luka; Srzic, Veljko

    2016-04-01

    Karst aquifers are very important groundwater resources around the world as well as in coastal part of Croatia. They consist of extremely complex structure defining by slow and laminar porous medium and small fissures and usually fast turbulent conduits/karst channels. Except simple lumped hydrological models that ignore high karst heterogeneity, full hydraulic (distributive) models have been developed exclusively by conventional finite element and finite volume elements considering complete karst heterogeneity structure that improves our understanding of complex processes in karst. Groundwater flow modeling in complex karst aquifers are faced by many difficulties such as a lack of heterogeneity knowledge (especially conduits), resolution of different spatial/temporal scales, connectivity between matrix and conduits, setting of appropriate boundary conditions and many others. Particular problem of karst flow modeling is verification of distributive models under real aquifer conditions due to lack of above-mentioned information. Therefore, we will show here possibility to verify karst flow models under the laboratory controlled conditions. Special 3-D karst flow model (5.6*2.6*2 m) consists of concrete construction, rainfall platform, 74 piezometers, 2 reservoirs and other supply equipment. Model is filled by fine sand (3-D porous matrix) and drainage plastic pipes (1-D conduits). This model enables knowledge of full heterogeneity structure including position of different sand layers as well as conduits location and geometry. Moreover, we know geometry of conduits perforation that enable analysis of interaction between matrix and conduits. In addition, pressure and precipitation distribution and discharge flow rates from both phases can be measured very accurately. These possibilities are not present in real sites what this model makes much more useful for karst flow modeling. Many experiments were performed under different controlled conditions such as different

  6. Implementation of Logic Flow in Planning and Production Control

    Directory of Open Access Journals (Sweden)

    Ulewicz Robert

    2016-03-01

    Full Text Available The article presents the results of analysis, the use of continuous flow of logic at the stage of production planning and control of the company producing furniture. The concept of continuous flow tends to regulate the flow of materials in a manner that provides the shortest flow path without unnecessary activities (Muda is a Japanese word meaning waste, a constant takt and defined throughput at constant resource requirements for the so-called transfer of material through the whole process. In the study Glenday’d sieve method was used to identify the correct area, which requires the value stream mapping, and areas called excessive complexity, which do not provide added value. The use of Glenday’s sieve method made it possible to identify areas in which it must be improve production capacity.

  7. Controlled synthesis of poly(3-hexylthiophene in continuous flow

    Directory of Open Access Journals (Sweden)

    Helga Seyler

    2013-07-01

    Full Text Available There is an increasing demand for organic semiconducting materials with the emergence of organic electronic devices. In particular, large-area devices such as organic thin-film photovoltaics will require significant quantities of materials for device optimization, lifetime testing and commercialization. Sourcing large quantities of materials required for the optimization of large area devices is costly and often impossible to achieve. Continuous-flow synthesis enables straight-forward scale-up of materials compared to conventional batch reactions. In this study, poly(3-hexylthiophene, P3HT, was synthesized in a bench-top continuous-flow reactor. Precise control of the molecular weight was demonstrated for the first time in flow for conjugated polymers by accurate addition of catalyst to the monomer solution. The P3HT samples synthesized in flow showed comparable performance to commercial P3HT samples in bulk heterojunction solar cell devices.

  8. Field-effect Flow Control in Polymer Microchannel Networks

    Science.gov (United States)

    Sniadecki, Nathan; Lee, Cheng S.; Beamesderfer, Mike; DeVoe, Don L.

    2003-01-01

    A new Bio-MEMS electroosmotic flow (EOF) modulator for plastic microchannel networks has been developed. The EOF modulator uses field-effect flow control (FEFC) to adjust the zeta potential at the Parylene C microchannel wall. By setting a differential EOF pumping rate in two of the three microchannels at a T-intersection with EOF modulators, the induced pressure at the intersection generated pumping in the third, field-free microchannel. The EOF modulators are able to change the magnitude and direction of the pressure pumping by inducing either a negative or positive pressure at the intersection. The flow velocity is tracked by neutralized fluorescent microbeads in the microchannels. The proof-of-concept of the EOF modulator described here may be applied to complex plastic ,microchannel networks where individual microchannel flow rates are addressable by localized induced-pressure pumping.

  9. Pump and Flow Control Subassembly of Thermal Control Subsystem for Photovoltaic Power Module

    Science.gov (United States)

    Motil, Brian; Santen, Mark A.

    1993-01-01

    The pump and flow control subassembly (PFCS) is an orbital replacement unit (ORU) on the Space Station Freedom photovoltaic power module (PVM). The PFCS pumps liquid ammonia at a constant rate of approximately 1170 kg/hr while providing temperature control by flow regulation between the radiator and the bypass loop. Also, housed within the ORU is an accumulator to compensate for fluid volumetric changes as well as the electronics and firmware for monitoring and control of the photovoltaic thermal control system (PVTCS). Major electronic functions include signal conditioning, data interfacing and motor control. This paper will provide a description of each major component within the PFCS along with performance test data. In addition, this paper will discuss the flow control algorithm and describe how the nickel hydrogen batteries and associated power electronics will be thermally controlled through regulation of coolant flow to the radiator.

  10. Phase Resolved Angular Velocity Control of Cross Flow Turbines

    Science.gov (United States)

    Strom, Benjamin; Brunton, Steven; Polagye, Brian

    2015-11-01

    Cross flow turbines have a number of operational advantages for the conversion of kinetic energy in marine or fluvial currents, but they are often less efficient than axial flow devices. Here a control scheme is presented in which the angular velocity of a cross flow turbine with two straight blades is prescribed as a function of azimuthal blade position, altering the time-varying effective angle of attack. Flume experiments conducted with a scale model turbine show approximately an 80% increase in turbine efficiency versus optimal constant angular velocity and constant resistive torque control schemes. Torque, drag, and lateral forces on one- and two-bladed turbines are analyzed and interpreted with bubble flow visualization to develop a simple model that describes the hydrodynamics responsible for the observed increase in mean efficiency. Challenges associated with implementing this control scheme on commercial-scale devices are discussed. If solutions are found, the performance increase presented here may impact the future development of cross flow turbines.

  11. Propagating nonpremixed edge-flames in a counterflow, annular slot burner under DC electric fields

    KAUST Repository

    Tran, Vu Manh

    2016-09-11

    Characteristics of propagating nonpremixed edge-flames were investigated in a counterflow, annular slot burner. A high-voltage direct current (DC) was applied to the lower part of the burner and the upper part was grounded, creating electric field lines perpendicular to the direction of edge-flame propagation. Upon application of an electric field, an ionic wind is caused by the migration of positive and negative ions to lower and higher electrical potential sides of a flame, respectively. Under an applied DC, we found a significant decrease in edge-flame displacement speeds unlike several previous studies, which showed an increase in displacement speed. Within a moderate range of field intensity, we found effects on flame propagation speeds to be negligible after correcting the flame displacement speed with respect to the unburned flow velocity ahead of the flame edge. This indicates that the displacement speed of an edge-flame strongly depends on ionic wind and that an electric field has little or no impact on propagation speed. The ionic wind also influenced the location of the stoichiometric contour in front of the propagating edge in a given configuration such that a propagating edge was relocated to the higher potential side due to an imbalance between ionic winds originating from positive and negative ions. In addition, we observed a steadily wrinkled flame following transient propagation of the edge-flame, a topic for future research. © 2016 The Combustion Institute

  12. Optimization of a premixed low-swirl burner for industrial applications

    International Nuclear Information System (INIS)

    Fable, S.E.; Cheng, R.K.

    2000-01-01

    This study was motivated by recent tests results showing that a 5cm i.d. low-swirl burner (LSB) stabilizes ultra-lean premixed turbulent flames up to 600kW. A parametric study has been performed to determine the optimum ultra-lean LSB configuration, i.e. one that will achieve low NOx and flame stability, for thermal input between 15kW to 150kW. Using Laser Doppler Velocimetry (LDV), non-reacting centerline velocity and rms fluctuation profiles were measured, and were found to show self-similar behavior. This self-similarity may explain why the flame remains stationary relative to the burner exit despite a change in bulk flow velocity from 5 to 90m/s. The recess distance of the swirler affects the shape of the mean and rms velocity profiles. Lean blow-off limits were also determined for various recess distances, and an optimum exit length was found that provides stable operation for ultra-lean flames

  13. Characterization of Liquid Fuel Evaporation of a Lifted Methanol Spray Flame in a Vitiated Coflow Burner

    Science.gov (United States)

    Cabra, Ricardo; Dibble, Robert W.; Chen, Jyh-Yuan

    2002-01-01

    An experimental investigation of lifted spray flames in a coflow of hot, vitiated gases is presented. The vitiated coflow burner is a spray flame that issues into a coaxial flow of hot combustion products from a lean, premixed H2/Air flame. The spray flame in a vitiated coflow emulates the combustion that occurs in many advanced combustors without the detailed fluid mechanics. Two commercially available laser diagnostic systems are used to characterize the spray flame and to demonstrate the vitiated coflow burner's amenability to optical investigation. The Ensemble Particle Concentration and Size (EPCS) system is used to measure the path-average droplet size distribution and liquid volume fraction at several axial locations while an extractive probe instrument named the Real-time Fuel-air Analyzer (RFA) is used to measure the air to fuel ratio downstream of the spray nozzle with high temporal and spatial resolution. The effect of coflow conditions (stoichiometry) and dilution of the fuel with water was studied with the EPCS optical system. As expected, results show that water retards the evaporation and combustion of fuels. Measurements obtained by the RFA extractive probe show that while the Delavan manufactured nozzle does distribute the fuel over the manufacturer specified spray angle, it unfortunately does not distribute the fuel uniformly, providing conditions that may result in the production of unwanted NOx. Despite some limitations due to the inherent nature of the experimental techniques, the two diagnostics can be readily applied to spray flames in the vitiated coflow environment.

  14. Tutorial on Feedback Control of Flows, Part I: Stabilization of Fluid Flows in Channels and Pipes

    Directory of Open Access Journals (Sweden)

    Ole M. Aamo

    2002-07-01

    Full Text Available The field of flow control has picked up pace over the past decade or so, on the promise of real-time distributed control on turbulent scales being realizable in the near future. This promise is due to the micromachining technology that emerged in the 1980s and developed at an amazing speed through the 1990s. In lab experiments, so called micro-electro-mechanical systems (MEMS that incorporate the entire detection-decision-actuation process on a single chip, have been batch processed in large numbers and assembled into flexible skins for gluing onto body-fluid interfaces for drag reduction purposes. Control of fluid flows span a wide variety of specialities. In Part I of this tutorial, we focus on the problem of reducing drag in channel and pipe flows by stabilizing the parabolic equilibrium profile using boundary feedback control. The control strategics used for this problem include classical control, based on the Nyquist criteria, and various optimal control techniques (H2, H-Infinity, as well as applications of Lyapunov stability theory.

  15. Intracycle angular velocity control of cross-flow turbines

    Science.gov (United States)

    Strom, Benjamin; Brunton, Steven L.; Polagye, Brian

    2017-08-01

    Cross-flow turbines, also known as vertical-axis turbines, are attractive for power generation from wind and water currents. Some cross-flow turbine designs optimize unsteady fluid forces and maximize power output by controlling blade kinematics within one rotation. One established method is to dynamically pitch the blades. Here we introduce a mechanically simpler alternative: optimize the turbine rotation rate as a function of angular blade position. We demonstrate experimentally that this approach results in a 59% increase in power output over standard control methods. Analysis of fluid forcing and blade kinematics suggest that power increase is achieved through modification of the local flow conditions and alignment of fluid force and rotation rate extrema. The result is a low-speed, structurally robust turbine that achieves high efficiency and could enable a new generation of environmentally benign turbines for renewable power generation.

  16. ac power control in the Core Flow Test Loop

    International Nuclear Information System (INIS)

    McDonald, D.W.

    1980-01-01

    This work represents a status report on a development effort to design an ac power controller for the Core Flow Test Loop. The Core Flow Test Loop will be an engineering test facility which will simulate the thermal environment of a gas-cooled fast-breeder reactor. The problems and limitations of using sinusoidal ac power to simulate the power generated within a nuclear reactor are addressed. The transformer-thyristor configuration chosen for the Core Flow Test Loop power supply is presented. The initial considerations, design, and analysis of a closed-loop controller prototype are detailed. The design is then analyzed for improved performance possibilities and failure modes are investigated at length. A summary of the work completed to date and a proposed outline for continued development completes the report

  17. Control volume based modelling of compressible flow in reciprocating machines

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2004-01-01

    , and multidimensional effects must be calculated using empirical correlations; correlations for steady state flow can be used as an approximation. A transformation that assumes ideal gas is presented for transforming equations for masses and energies in control volumes into the corresponding pressures and temperatures......An approach to modelling unsteady compressible flow that is primarily one dimensional is presented. The approach was developed for creating distributed models of machines with reciprocating pistons but it is not limited to this application. The approach is based on the integral form of the unsteady...... conservation laws for mass, energy, and momentum applied to a staggered mesh consisting of two overlapping strings of control volumes. Loss mechanisms can be included directly in the governing equations of models by including them as terms in the conservation laws. Heat transfer, flow friction...

  18. Variability of sap flow on forest hillslopes: patterns and controls

    Science.gov (United States)

    Hassler, Sibylle; Blume, Theresa

    2013-04-01

    Sap flow in trees is an essential variable in integrated studies of hydrologic fluxes. It gives indication of transpiration rates for single trees and, with a suitable method of upscaling, for whole stands. This information is relevant for hydrologic and climate models, especially for the prediction of change in water fluxes in the soil-plant-atmosphere continuum under climate change. To this end, we do not only need knowledge concerning the response of sapflow to atmospheric forcing but also an understanding of the main controls on its spatial variability. Our study site consists of several subcatchments of the Attert basin in Luxembourg underlain by schists of the Ardennes massif. Within these subcatchments we measure sap flow in more than 20 trees on a range of forested hillslopes covered by a variety of temperate deciduous tree species such as beech, oak, hornbeam and maple as well as conifers such as firs. Our sap flow sensors are based on the heat pulse velocity method and consist of three needles, one needle acting as the heating device and the other two holding three thermistors each, enabling us to simultaneously measure sap flow velocity at three different depths within the tree. In close proximity to the trees we collect additional data on soil moisture, matric potential and groundwater levels. First results show that the sensor design seems promising for an upscaling of the measured sap flow velocities to sap flow at the tree level. The maximum depth of actively used sapwood as well as the decrease in sap flow velocity with increasing depth in the tree can be determined by way of the three thermistors. Marked differences in sap flow velocity profiles are visible between the different species, resulting in differences in sap flow for trees of similar diameter. We examine the range of tree sap flow values and variation due to species, size class, slope position and exposition and finally relate them to the dynamics of soil moisture conditions with the

  19. Evaluation of the FAA Advanced Flow Control Procedures.

    Science.gov (United States)

    1972-01-01

    The report is an evaluation of the present FAA Advanced Flow Control Procedures (AFCP), based on data gathered from its implementation on February 5, 1971 and on a fast-time digital simulation of traffic feeding into the NY airports on that day. The ...

  20. Flow intake control using dry-weather forecast

    Science.gov (United States)

    Icke, Otto; van Schagen, Kim; Huising, Christian; Wuister, Jasper; van Dijk, Edward; Budding, Arjan

    2017-08-01

    Level-based control of the influent flow causes peak discharges at a waste water treatment plant (WWTP) after rainfall events. Furthermore, the capacity of the post-treatment is in general smaller than the maximum hydraulic capacity of the WWTP. This results in a significant bypass of the post-treatment during peak discharge. The optimisation of influent flow reduces peak discharge, and increases the treatment efficiency of the whole water cycle, which benefits the surface water quality. In this paper, it is shown that half of the bypasses of the post-treatment can be prevented by predictive control. A predictive controller for influent flow is implemented using the Aquasuitetext">® Advanced Monitoring and Control platform. Based on real-time measured water levels in the sewerage and both rainfall and dry-weather flow (DWF) predictions, a discharge limitation is determined by a volume optimisation technique. For the analysed period (February-September 2016) results at WWTP Bennekom show that about 50 % of bypass volume can be prevented. Analysis of single rainfall events shows that the used approach is still conservative and that the bypass can be even further decreased by allowing discharge limitation during precipitation.

  1. A stochastic programming approach to manufacturing flow control

    OpenAIRE

    Haurie, Alain; Moresino, Francesco

    2012-01-01

    This paper proposes and tests an approximation of the solution of a class of piecewise deterministic control problems, typically used in the modeling of manufacturing flow processes. This approximation uses a stochastic programming approach on a suitably discretized and sampled system. The method proceeds through two stages: (i) the Hamilton-Jacobi-Bellman (HJB) dynamic programming equations for the finite horizon continuous time stochastic control problem are discretized over a set of sample...

  2. Biological control of schistosome transmission in flowing water habitats.

    Science.gov (United States)

    Jobin, W R; Laracuente, A

    1979-09-01

    Marisa cornuarietis was evaluated in Puerto Rico for control of schistosome transmission in flowing water. A population of Biomphalaria glabrata and their schistosome infections disappeared after introduction of 20,000 M. cornuarietis to an endemic stream, while in nearby untreated streams the B. glabrata population remained stable and the schistosome prevalence increased. This method cost U.S. $0.10 per capita for over a year of protection, 5%-10% of the cost of chemical control.

  3. Nocturnal insects use optic flow for flight control

    OpenAIRE

    Baird, Emily; Kreiss, Eva; Wcislo, William; Warrant, Eric; Dacke, Marie

    2011-01-01

    To avoid collisions when navigating through cluttered environments, flying insects must control their flight so that their sensory systems have time to detect obstacles and avoid them. To do this, day-active insects rely primarily on the pattern of apparent motion generated on the retina during flight (optic flow). However, many flying insects are active at night, when obtaining reliable visual information for flight control presents much more of a challenge. To assess whether nocturnal flyin...

  4. Evaluation of a high-temperature burner-duct-recuperator system

    Science.gov (United States)

    1990-07-01

    The U.S. Department of Energy's (DOE) Office of Industrial Technologies (OIT) sponsors research and development (R and D) to improve the energy efficiency of American industry and to provide for fuel flexibility. OIT has funded a multiyear R and D project by the Babcock and Wilcox Company (B and W) to design, fabricate, field test, and evaluate a high-temperature burner-duct-recuperator (HTBDR) system. This ceramic-based recuperator system recovers waste heat from the corrosive, high-temperature (2170 F) flue gas stream of a steel soaking pit to preheat combustion air to as high as 1700 F. The preheated air is supplied to a high-temperature burner. The B and W R and D program, which is now complete, involved several activities, including selecting and evaluating ceramic materials, designing the system, and developing and evaluating the prototype. In addition, a full-scale unit was tested at a B and W steel soaking pit. The full-scale system consisted of a modular single-stage ceramic recuperator, a conventional two-pass metallic recuperator, a high-temperature burner, fans, insulated ducting, and associated controls and instrumentation. The metallic recuperator preheated combustion air to about 750 F before it passed to the ceramic module. This technical case study describes the DOE/B and W recuperator project and highlights the field tests of the full-scale recuperator system. The document makes results of field tests and data analysis available to other researchers and private industry. It discusses project status, summarizes field tests, and reviews the potential effects the technology will have on energy use and system economics.

  5. Microrelief-Controlled Overland Flow Generation: Laboratory and Field Experiments

    Directory of Open Access Journals (Sweden)

    Xuefeng Chu

    2015-01-01

    Full Text Available Surface microrelief affects overland flow generation and the related hydrologic processes. However, such influences vary depending on other factors such as rainfall characteristics, soil properties, and initial soil moisture conditions. Thus, in-depth research is needed to better understand and evaluate the combined effects of these factors on overland flow dynamics. The objective of this experimental study was to examine how surface microrelief, in conjunction with the factors of rainfall, soil, and initial moisture conditions, impacts overland flow generation and runoff processes in both laboratory and field settings. A series of overland flow experiments were conducted for rough and smooth surfaces that represented distinct microtopographic characteristics and the experimental data were analyzed and compared. Across different soil types and initial moisture conditions, both laboratory and field experiments demonstrated that a rough soil surface experienced a delayed initiation of runoff and featured a stepwise threshold flow pattern due to the microrelief-controlled puddle filling-spilling-merging dynamics. It was found from the field experiments that a smooth plot surface was more responsive to rainfall variations especially during an initial rainfall event. However, enhanced capability of overland flow generation and faster puddle connectivity of a rough field plot occurred during the subsequent rain events.

  6. Flow Control in Wells Turbines for Harnessing Maximum Wave Power

    Science.gov (United States)

    Garrido, Aitor J.; Garrido, Izaskun; Otaola, Erlantz; Maseda, Javier

    2018-01-01

    Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness. PMID:29439408

  7. Flow Control in Wells Turbines for Harnessing Maximum Wave Power.

    Science.gov (United States)

    Lekube, Jon; Garrido, Aitor J; Garrido, Izaskun; Otaola, Erlantz; Maseda, Javier

    2018-02-10

    Oceans, and particularly waves, offer a huge potential for energy harnessing all over the world. Nevertheless, the performance of current energy converters does not yet allow us to use the wave energy efficiently. However, new control techniques can improve the efficiency of energy converters. In this sense, the plant sensors play a key role within the control scheme, as necessary tools for parameter measuring and monitoring that are then used as control input variables to the feedback loop. Therefore, the aim of this work is to manage the rotational speed control loop in order to optimize the output power. With the help of outward looking sensors, a Maximum Power Point Tracking (MPPT) technique is employed to maximize the system efficiency. Then, the control decisions are based on the pressure drop measured by pressure sensors located along the turbine. A complete wave-to-wire model is developed so as to validate the performance of the proposed control method. For this purpose, a novel sensor-based flow controller is implemented based on the different measured signals. Thus, the performance of the proposed controller has been analyzed and compared with a case of uncontrolled plant. The simulations demonstrate that the flow control-based MPPT strategy is able to increase the output power, and they confirm both the viability and goodness.

  8. Combustion stability and thermal efficiency in a porous media burner for LPG cooking in the food industry using Al_2O_3 particles coming from grinding wastes

    International Nuclear Information System (INIS)

    Herrera, Bernardo; Cacua, Karen; Olmos-Villalba, Luis

    2015-01-01

    Cooking is one of the most thermal-energy consuming processes in the food industry and development of devices that contribute to decrease the consumption of fossil fuel is a matter of great importance. This decreasing in consumption can both enlarge competitiveness in the enterprises of this sector and reduce emissions of greenhouse gases and other toxic combustion by products such as, carbon monoxide and nitrogen oxides. A porous burner made of a bed of Al_2O_3 particles coming from grinding residues and combined with ceramic foam of SiSiC has been evaluated respect to Liquefied Petroleum Gas combustion stability and thermal efficiency for cooking in food industry. The results showed that for specific heat input rate lower than 154 kW/m"2, the upper and lower equivalence ratio on the stability limit follow approximately a linear trend, as well as the wide of the range of stability remains constant. But this trend is broken when higher heat input rate is applied. Also, every equivalence ratio for stable combustion was in the lean ratio and stoichiometric combustion values were not feasible because flashback occurred. Emissions of CO were in acceptable values lower than 25 ppm for specific heat input rate lower than 154 kW/m"2 but an important rising in the CO emissions could be seen when the burner worked at higher heat input rate due to a moderate lift-off and quenching on the surface of the burner. Thermal efficiency was calculated in two different working ways: the “radiation–convection” and “conduction”. Thermal efficiency in the “radiation–convection” was between 15.7% and 23.6%, which are lower than the average thermal efficiency of the conventional free-flame burner. But the “conduction” mode showed a significant advantage respect to free flame conventional burners, since it could improve the thermal efficiency between 7% and 14%. The improvement in efficiency and the possibility of interrupting the flow of fuel in a cyclical operation

  9. Integrated Lateral Flow Device for Flow Control with Blood Separation and Biosensing

    Directory of Open Access Journals (Sweden)

    Veronica Betancur

    2017-12-01

    Full Text Available Lateral flow devices are versatile and serve a wide variety of purposes, including medical, agricultural, environmental, and military applications. Yet, the most promising opportunities of these devices for diagnosis might reside in point-of-care (POC applications. Disposable paper-based lateral flow strips have been of particular interest, because they utilize low-cost materials and do not require expensive fabrication instruments. However, there are constraints on tuning flow rates and immunoassays functionalization in papers, as well as technical challenges in sensors’ integration and concentration units for low-abundant molecular detection. In the present work, we demonstrated an integrated lateral flow device that applied the capillary forces with functionalized polymer-based microfluidics as a strategy to realize a portable, simplified, and self-powered lateral flow device (LFD. The polydimethylsiloxane (PDMS surface was rendered hydrophilic via functionalization with different concentrations of Pluronic F127. Controlled flow is a key variable for immunoassay-based applications for providing enough time for protein binding to antibodies. The flow rate of the integrated LFD was regulated by the combination of multiple factors, including Pluronic F127 functionalized surface properties and surface treatments of microchannels, resistance of the integrated flow resistor, the dimensions of the microstructures and the spacing between them in the capillary pump, the contact angles, and viscosity of the fluids. Various plasma flow rates were regulated and achieved in the whole device. The LFD combined the ability to separate high quality plasma from human whole blood by using a highly asymmetric plasma separation membrane, and created controlled and steady fluid flow using capillary forces produced by the interfacial tensions. Biomarker immunoglobulin G (IgG detection from plasma was demonstrated with a graphene nanoelectronic sensor integrated

  10. Typing Local Control and State Using Flow Analysis

    Science.gov (United States)

    Guha, Arjun; Saftoiu, Claudiu; Krishnamurthi, Shriram

    Programs written in scripting languages employ idioms that confound conventional type systems. In this paper, we highlight one important set of related idioms: the use of local control and state to reason informally about types. To address these idioms, we formalize run-time tags and their relationship to types, and use these to present a novel strategy to integrate typing with flow analysis in a modular way. We demonstrate that in our separation of typing and flow analysis, each component remains conventional, their composition is simple, but the result can handle these idioms better than either one alone.

  11. Analysis of flow instability in steam turbine control valves

    International Nuclear Information System (INIS)

    Pluviose, M.

    1981-01-01

    With the sponsorship of Electricite de France and the French steam turbine manufacturers, the Gas Turbine Laboratory of CETIM has started a research about the unsteady phenomena of flow in control valves of steam turbines. The existence of unsteady embossment in the valve cone at rise has been as certained, and a conventional computing procedure has been applied to locate the shock waves in the valve. These shock waves may suddenly arise at some valve lifts and give way to fluttering. Valve geometries attenuating instability of flow and increasing therefore the reliability of such equipment are proposed [fr

  12. Quantifying, characterizing, and controlling information flow in ultracold atomic gases

    International Nuclear Information System (INIS)

    Haikka, P.; McEndoo, S.; Maniscalco, S.; De Chiara, G.; Palma, G. M.

    2011-01-01

    We study quantum information flow in a model comprised of a trapped impurity qubit immersed in a Bose-Einstein-condensed reservoir. We demonstrate how information flux between the qubit and the condensate can be manipulated by engineering the ultracold reservoir within experimentally realistic limits. We show that this system undergoes a transition from Markovian to non-Markovian dynamics, which can be controlled by changing key parameters such as the condensate scattering length. In this way, one can realize a quantum simulator of both Markovian and non-Markovian open quantum systems, the latter ones being characterized by a reverse flow of information from the background gas (reservoir) to the impurity (system).

  13. Automatized material and radioactivity flow control tool in decommissioning process

    International Nuclear Information System (INIS)

    Rehak, I.; Vasko, M.; Daniska, V.; Schultz, O.

    2009-01-01

    In this presentation the automatized material and radioactivity flow control tool in decommissioning process is discussed. It is concluded that: computer simulation of the decommissioning process is one of the important attributes of computer code Omega; one of the basic tools of computer optimisation of decommissioning waste processing are the tools of integral material and radioactivity flow; all the calculated parameters of materials are stored in each point of calculation process and they can be viewed; computer code Omega represents opened modular system, which can be improved; improvement of the module of optimisation of decommissioning waste processing will be performed in the frame of improvement of material procedures and scenarios.

  14. Fluidic actuators for active flow control on airframe

    Science.gov (United States)

    Schueller, M.; Weigel, P.; Lipowski, M.; Meyer, M.; Schlösser, P.; Bauer, M.

    2016-04-01

    One objective of the European Projects AFLoNext and Clean Sky 2 is to apply Active Flow Control (AFC) on the airframe in critical aerodynamic areas such as the engine/wing junction or the outer wing region for being able to locally improve the aerodynamics in certain flight conditions. At the engine/wing junction, AFC is applied to alleviate or even eliminate flow separation at low speeds and high angle of attacks likely to be associated with the integration of underwing- mounted Ultra High Bypass Ratio (UHBR) engines and the necessary slat-cut-outs. At the outer wing region, AFC can be used to allow more aggressive future wing designs with improved performance. A relevant part of the work on AFC concepts for airframe application is the development of suitable actuators. Fluidic Actuated Flow Control (FAFC) has been introduced as a Flow Control Technology that influences the boundary layer by actively blowing air through slots or holes out of the aircraft skin. FAFC actuators can be classified by their Net Mass Flux and accordingly divided into ZNMF (Zero Net Mass Flux) and NZNMF (Non Zero Net-Mass-Flux) actuators. In the frame of both projects, both types of the FAFC actuator concepts are addressed. In this paper, the objectives of AFC on the airframe is presented and the actuators that are used within the project are discussed.

  15. LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

    International Nuclear Information System (INIS)

    Warzecha, Piotr; Boguslawski, Andrzej

    2014-01-01

    Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

  16. Stabilising falling liquid film flows using feedback control

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Alice B., E-mail: alice.thompson1@imperial.ac.uk; Gomes, Susana N.; Pavliotis, Grigorios A.; Papageorgiou, Demetrios T. [Department of Mathematics, Imperial College London, London SW7 2AZ (United Kingdom)

    2016-01-15

    Falling liquid films become unstable due to inertial effects when the fluid layer is sufficiently thick or the slope sufficiently steep. This free surface flow of a single fluid layer has industrial applications including coating and heat transfer, which benefit from smooth and wavy interfaces, respectively. Here, we discuss how the dynamics of the system are altered by feedback controls based on observations of the interface height, and supplied to the system via the perpendicular injection and suction of fluid through the wall. In this study, we model the system using both Benney and weighted-residual models that account for the fluid injection through the wall. We find that feedback using injection and suction is a remarkably effective control mechanism: the controls can be used to drive the system towards arbitrary steady states and travelling waves, and the qualitative effects are independent of the details of the flow modelling. Furthermore, we show that the system can still be successfully controlled when the feedback is applied via a set of localised actuators and only a small number of system observations are available, and that this is possible using both static (where the controls are based on only the most recent set of observations) and dynamic (where the controls are based on an approximation of the system which evolves over time) control schemes. This study thus provides a solid theoretical foundation for future experimental realisations of the active feedback control of falling liquid films.

  17. Nocturnal insects use optic flow for flight control.

    Science.gov (United States)

    Baird, Emily; Kreiss, Eva; Wcislo, William; Warrant, Eric; Dacke, Marie

    2011-08-23

    To avoid collisions when navigating through cluttered environments, flying insects must control their flight so that their sensory systems have time to detect obstacles and avoid them. To do this, day-active insects rely primarily on the pattern of apparent motion generated on the retina during flight (optic flow). However, many flying insects are active at night, when obtaining reliable visual information for flight control presents much more of a challenge. To assess whether nocturnal flying insects also rely on optic flow cues to control flight in dim light, we recorded flights of the nocturnal neotropical sweat bee, Megalopta genalis, flying along an experimental tunnel when: (i) the visual texture on each wall generated strong horizontal (front-to-back) optic flow cues, (ii) the texture on only one wall generated these cues, and (iii) horizontal optic flow cues were removed from both walls. We find that Megalopta increase their groundspeed when horizontal motion cues in the tunnel are reduced (conditions (ii) and (iii)). However, differences in the amount of horizontal optic flow on each wall of the tunnel (condition (ii)) do not affect the centred position of the bee within the flight tunnel. To better understand the behavioural response of Megalopta, we repeated the experiments on day-active bumble-bees (Bombus terrestris). Overall, our findings demonstrate that despite the limitations imposed by dim light, Megalopta-like their day-active relatives-rely heavily on vision to control flight, but that they use visual cues in a different manner from diurnal insects. This journal is © 2011 The Royal Society

  18. Influence of the technique for injection of flue gas and the configuration of the swirl burner throat on combustion of gaseous fuel and formation of nitrogen oxides in the flame

    Science.gov (United States)

    Dvoinishnikov, V. A.; Khokhlov, D. A.; Knyaz'kov, V. P.; Ershov, A. Yu.

    2017-05-01

    How the points at which the flue gas was injected into the swirl burner and the design of the burner outlet influence the formation and development of the flame in the submerged space, as well as the formation of nitrogen oxides in the combustion products, have been studied. The object under numerical investigation is the flame of the GMVI combined (oil/gas) burner swirl burner fitted with a convergent, biconical, cylindrical, or divergent throat at the burner outlet with individual supply of the air and injection of the gaseous fuel through tubing. The burners of two designs were investigated; they differ by the absence or presence of an inlet for individual injection of the flue gas. A technique for numerical simulation of the flame based on the CFD methods widely used in research of this kind underlies the study. Based on the summarized results of the numerical simulation of the processes that occur in jet flows, the specific features of the aerodynamic pattern of the flame have been established. It is shown that the flame can be conventionally divided into several sections over its length in all investigations. The lengths of each of the sections, as well as the form of the fields of axial velocity, temperatures, concentrations of the fuel, oxygen, and carbon and nitrogen oxides, are different and determined by the design features of the burner, the flow rates of the agent, and the compositions of the latter in the burner ducts as well as the configuration of the burner throat and the temperature of the environment. To what degree the burner throat configuration and the techniques for injection of the flue gas at different ambient temperatures influence the formation of nitrogen oxides has been established. It is shown that the supply of the recirculation of flue gas into the fuel injection zone enables a considerable reduction in the formation of nitrogen oxides in the flame combustion products. It has been established that the locations of the zones of

  19. Strategic Management Accounting in Organizations’ Cash Flow Control

    Directory of Open Access Journals (Sweden)

    Y. P. Vetrov

    2017-09-01

    Full Text Available The article deals with the various interpretations of the term "strategic management accounting". The role and importance of strategic management accounting in the organization’s cash flows control are investigated. The accounting and analytical models of strategic management accounting are analyzed. The territorial scope of this article covers the Russian Federation. The study concludes that the system of assessment parameters of organization’s financial condition should cover all its aspects, namely, financial sustainability, solvency, liquidity and business activity. Hence, strategic management accounting of cash flows makes it possible to correctly set information base to monitor financial flows of a company which responds the tends of market economy and allows to make optimal management decisions.

  20. DESIGN OF SLIT DAMS FOR CONTROLLING STONY DEBRIS FLOWS

    Institute of Scientific and Technical Information of China (English)

    Hui-Pang LIEN

    2003-01-01

    A new method to a slit dam for controlling the stony debris flow has been derived based on the mass conservation law of the stony debris flow passing through a slit dam and the laboratory experiment results.This new method is then combined with three primary efficiency expressions: the dimensionless sediment outflow ratio,the sediment concentration ratio,and the sediment storage rate to develop a simple module,with which the height and the spacing of the posts,as well as the total spacing of slit dam are determined.Furthermore,these expressions can also be applied to check those slit dams that have already been constructed with their effectiveness against various magnitudes of the debris flow. The comparison between these expressions and laboratory data is in reasonable agreement.

  1. Numerical Studies of a Fluidic Diverter for Flow Control

    Science.gov (United States)

    Gokoglu, Suleyman A.; Kuczmarski, Maria A.; Culley, Dennis E.; Raghu, Surya

    2009-01-01

    The internal flow structure in a specific fluidic diverter is studied over a range from low subsonic to sonic inlet conditions by a time-dependent numerical analysis. The understanding will aid in the development of fluidic diverters with minimum pressure losses and advanced designs of flow control actuators. The velocity, temperature and pressure fields are calculated for subsonic conditions and the self-induced oscillatory behavior of the flow is successfully predicted. The results of our numerical studies have excellent agreement with our experimental measurements of oscillation frequencies. The acoustic speed in the gaseous medium is determined to be a key factor for up to sonic conditions in governing the mechanism of initiating the oscillations as well as determining its frequency. The feasibility of employing plasma actuation with a minimal perturbation level is demonstrated in steady-state calculations to also produce oscillation frequencies of our own choosing instead of being dependent on the fixed-geometry fluidic device.

  2. Flow induced vibration studies on PFBR control plug components

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, V., E-mail: prakash@igcar.gov.in [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India); Kumar, P. Anup; Anandaraj, M.; Thirumalai, M.; Anandbabu, C.; Rajan, K.K. [Fast Reactor Technology Group, Indira Gandhi Centre for Atomic Research, Kalpakkam, Tamilnadu (India)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Flow induced vibration studies on Prototype Fast Breeder Reactor control plug model carried out. Black-Right-Pointing-Pointer Velocity similitude was followed for the study. Black-Right-Pointing-Pointer Frequencies and amplitude of vibrations of various control plug components measured. Black-Right-Pointing-Pointer Overall values of vibration are well within permissible limits. - Abstract: The construction of Prototype Fast Breeder Reactor (PFBR), a 500 MWe liquid sodium cooled reactor, is in progress at Kalpakkam in India. Control plug (CP) is located right above the core subassemblies in the hot pool. Control plug is an important component as many of the critical reactor parameters are sensed and controlled by the components housed in the control plug assembly. In PFBR primary circuit, components are basically thin walled, slender shells with diameter to thickness ratio ranging from 100 to 650. These components are prone to flow induced vibrations. The existence of free liquid (sodium) surfaces, which is the source of sloshing phenomenon and the operation of primary sodium pump in the primary pool are other potential sources of vibration of reactor components. Control plug is a hollow cylindrical shell structure and provides passages and support for 12 absorber rod drive mechanisms (ARDM) which consists of 9 control and safety rods and 3 diverse safety rods, 210 thermo wells to measure the sodium temperature at the exit of various fuel subassemblies, three failed fuel localization modules (FFLM) and acoustic detectors. It consists of a core cover plate (CCP), which forms the bottom end, two intermediate supports plate, i.e. lower stay plate (LSP) and upper stay plate (USP) and an outer shell. The CCP is located at a distance of 1.3 m from the core top. With such a gap, there will be long free hanging length of the thermocouple sleeves, Delayed neutron detector (DND) sampling tubes and ARDM shroud tubes and hence they are

  3. Experimental study of a separated jets burner: application to the natural gas-pure oxygen combustion; Etude experimentale du comportement de bruleurs a jets separes: application a la combustion gaz naturel-oxygene pur

    Energy Technology Data Exchange (ETDEWEB)

    Salentey, L.

    2002-04-15

    The evolution of pollution standards and the optimisation of furnaces performances require a development of new burner generation and also the improvement of combustion techniques. Actually, the use of oxy-combustion in separated jets burners offers interesting prospects for NO{sub x} emission reduction and on the modularity of flames properties (lift off, flame front topology, flame length). The complex geometry of those burners leads to several problems like the three-dimensional character of the flow, which may sometimes disturb the flame stability as flames are lifted above the burner. This experimental study deals with a simplified version of that kind of burner constituted with a central natural gas jet surrounded by two oxygen jets. Primary, the study of non-reactive jet was planned in order to understand dynamic and mixture phenomena involved between jets and to provide a database useful for the computer code validation. The reactive flow developed in a furnace, which simulates the real conditions, had been characterised. The studies of the dynamic field using Laser Doppler Velocimetry (LDV) and of the turbulent mixture by conditional Laser tomography were supplemented in combustion by the visualisation of the spontaneous emission of radical OH, in the initial and final zone of the oxy-flames, like by the measurement of pollutants like NO{sub x} and soot. The measurements carried out while varying speeds of injection as well as the gap between the jets made possible the highlight of the influence of these parameters upon the stabilisation of the oxy-flames as well as the modification of the topology and the characteristics of the flows. The comparison of the measurements made in non-reactive and reactive flow shows the influence of oxy-combustion on the dynamic and scalar development of the flow for this type of burners. (author)

  4. Active Flow Control in an Aggressive Transonic Diffuser

    Science.gov (United States)

    Skinner, Ryan W.; Jansen, Kenneth E.

    2017-11-01

    A diffuser exchanges upstream kinetic energy for higher downstream static pressure by increasing duct cross-sectional area. The resulting stream-wise and span-wise pressure gradients promote extensive separation in many diffuser configurations. The present computational work evaluates active flow control strategies for separation control in an asymmetric, aggressive diffuser of rectangular cross-section at inlet Mach 0.7 and Re 2.19M. Corner suction is used to suppress secondary flows, and steady/unsteady tangential blowing controls separation on both the single ramped face and the opposite flat face. We explore results from both Spalart-Allmaras RANS and DDES turbulence modeling frameworks; the former is found to miss key physics of the flow control mechanisms. Simulated baseline, steady, and unsteady blowing performance is validated against experimental data. Funding was provided by Northrop Grumman Corporation, and this research used resources of the Argonne Leadership Computing Facility, which is a DOE Office of Science User Facility supported under Contract DE-AC02-06CH11357.

  5. Frequency dependence and frequency control of microbubble streaming flows

    Science.gov (United States)

    Wang, Cheng; Rallabandi, Bhargav; Hilgenfeldt, Sascha

    2013-02-01

    Steady streaming from oscillating microbubbles is a powerful actuating mechanism in microfluidics, enjoying increased use due to its simplicity of manufacture, ease of integration, low heat generation, and unprecedented control over the flow field and particle transport. As the streaming flow patterns are caused by oscillations of microbubbles in contact with walls of the set-up, an understanding of the bubble dynamics is crucial. Here we experimentally characterize the oscillation modes and the frequency response spectrum of such cylindrical bubbles, driven by a pressure variation resulting from ultrasound in the range of 1 kHz raisebox {-.9ex{stackrel{textstyle <}{˜ }} }f raisebox {-.9ex{stackrel{textstyle <}{˜ }} } 100 kHz. We find that (i) the appearance of 2D streaming flow patterns is governed by the relative amplitudes of bubble azimuthal surface modes (normalized by the volume response), (ii) distinct, robust resonance patterns occur independent of details of the set-up, and (iii) the position and width of the resonance peaks can be understood using an asymptotic theory approach. This theory describes, for the first time, the shape oscillations of a pinned cylindrical bubble at a wall and gives insight into necessary mode couplings that shape the response spectrum. Having thus correlated relative mode strengths and observed flow patterns, we demonstrate that the performance of a bubble micromixer can be optimized by making use of such flow variations when modulating the driving frequency.

  6. Climatic and geomorphic controls on low flow hydrograph recession

    Science.gov (United States)

    Chandler, D. G.; Daley, M.; Kasaee Roodsari, B.; Shaw, S. B.; McNamara, J.

    2017-12-01

    Large scale operational hydrologic models should be capable of predicting seasonally low flow and stream intermittency as well as peak flow and inundation. We contrast examples of controls on low flow exerted by geomorphic and climatic setting at small catchment study sites in the Northeast and Northwest of the USA to indicate differences in hydrologic processes. Both regions accumulate winter snowpack and have an extended spring freshet, but the Reynolds Creek CZO and Dry Creek Experimental Watershed (both in Idaho mountains) experience a protracted summer drought, with occasional storms whereas precipitation free periods greater than five days are uncommon in the hilly Sleepers River (Vermont), and Yellow Barn State Forest (New York) and at Ley Creek, on a glacial plain (New York). At both Dry Creek and Reynolds Creek, headwater stream flow direction was transverse to groundwater, and below field capacity discharge was well related to either the ground water surface or corresponded to inversion of the hydraulic gradient over the depth of the soil. At all sites except Ley Creek, the headwaters became intermittent as the main tributary discharge declined, often disconnecting the surface source springs and seeps from the valley bottom stream. At the Idaho sites recession analysis for main stem was further complicated by consumptive use for irrigation and domestic wells. Modeling the recession characteristics of these various settings and across stream orders results in a variety of exponent values for power law scaling approaches that indicate the importance of site context for modeling low flow.

  7. Flow control of micro-ramps on supersonic forward-facing step flow

    International Nuclear Information System (INIS)

    Zhang Qing-Hu; Zhu Tao; Wu Anping; Yi Shihe

    2016-01-01

    The effects of the micro-ramps on supersonic turbulent flow over a forward-facing step (FFS) was experimentally investigated in a supersonic low-noise wind tunnel at Mach number 3 using nano-tracer planar laser scattering (NPLS) and particle image velocimetry (PIV) techniques. High spatiotemporal resolution images and velocity fields of supersonic flow over the testing model were captured. The fine structures and their spatial evolutionary characteristics without and with the micro-ramps were revealed and compared. The large-scale structures generated by the micro-ramps can survive the downstream FFS flowfield. The micro-ramps control on the flow separation and the separation shock unsteadiness was investigated by PIV results. With the micro-ramps, the reduction in the range of the reversal flow zone in streamwise direction is 50% and the turbulence intensity is also reduced. Moreover, the reduction in the average separated region and in separation shock unsteadiness are 47% and 26%, respectively. The results indicate that the micro-ramps are effective in reducing the flow separation and the separation shock unsteadiness. (paper)

  8. CFD Study of NACA 0018 Airfoil with Flow Control

    Science.gov (United States)

    Eggert, Christopher A.; Rumsey, Christopher L.

    2017-01-01

    The abilities of two different Reynolds-Averaged Navier-Stokes codes to predict the effects of an active flow control device are evaluated. The flow control device consists of a blowing slot located on the upper surface of an NACA 0018 airfoil, near the leading edge. A second blowing slot present on the airfoil near mid-chord is not evaluated here. Experimental results from a wind tunnel test show that a slot blowing with high momentum coefficient will increase the lift of the airfoil (compared to no blowing) and delay flow separation. A slot with low momentum coefficient will decrease the lift and induce separation even at low angles of attack. Two codes, CFL3D and FUN3D, are used in two-dimensional computations along with several different turbulence models. Two of these produced reasonable results for this flow, when run fully turbulent. A more advanced transition model failed to predict reasonable results, but warrants further study using different inputs. Including inviscid upper and lower tunnel walls in the simulations was found to be important in obtaining pressure distributions and lift coefficients that best matched experimental data. A limited number of three-dimensional computations were also performed.

  9. Flow measurement and control in the defense waste process

    International Nuclear Information System (INIS)

    Heckendorn, F.M. II.

    1985-01-01

    The Defense Waste Processing Facility (DWPF) for immobilizing Savannah River Plant (SRP) high-level radioactive waste is now under construction. Previously stored waste is retrieved and processed into a glass matrix for permanent storage. The equipment operates in an entirely remote environment for both processing and maintenance due to the highly radioactive nature of the waste. A fine powdered glass frit is mixed with the waste prior to its introduction as a slurry into an electric glass furnace. The slurry is Bingham plastic in nature and of high viscosity. This combination of factors has created significant problems in flow measurement and control. Specialized pieces of equipment have been demonstrated that will function properly in a highly abrasive environment while receiving no maintenance during their lifetime. Included are flow meters, flow control technology, flow switching, and remote connections. No plastics or elastomers are allowed in contact with fluids and all electronic components are mounted remotely. Both two- and three-way valves are used. Maintenance is by crane replacement of process sections, utilizing specialized connectors. All portions of the above are now operating full scale (radioactively cold) at the test facility at SRP. 4 references, 8 figures

  10. Structure of diffusion flames from a vertical burner

    Science.gov (United States)

    Mark A. Finney; Dan Jimenez; Jack D. Cohen; Isaac C. Grenfell; Cyle Wold

    2010-01-01

    Non-steady and turbulent flames are commonly observed to produce flame contacts with adjacent fuels during fire spread in a wide range of fuel bed depths. A stationary gas-fired burner (flame wall) was developed to begin study of flame edge variability along an analagous vertical fuel source. This flame wall is surrogate for a combustion interface at the edge of a deep...

  11. Effect of cycled combustion ageing on a cordierite burner plate

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Eugenio [Instituto de Ceramica y Vidrio, CSIC, c/ Kelsen 5, Campus de Cantoblanco, 28049 Madrid (Spain); Gancedo, J. Ramon [Instituto de Quimica Fisica ' Rocasolano' , CSIC, c/ Serrano 119, 28006 Madrid (Spain); Gracia, Mercedes, E-mail: rocgracia@iqfr.csic.es [Instituto de Quimica Fisica ' Rocasolano' , CSIC, c/ Serrano 119, 28006 Madrid (Spain)

    2010-11-15

    A combination of {sup 57}Fe-Moessbauer spectroscopy and X-ray Powder Diffraction analysis has been employed to study modifications in chemical and mechanical stability occurring in a cordierite burner aged under combustion conditions which simulate the working of domestic boilers. Moessbauer study shows that Fe is distributed into the structural sites of the cordierite lattice as Fe{sup 2+} and Fe{sup 3+} ions located mostly at octahedral sites. Ferric oxide impurities, mainly hematite, are also present in the starting cordierite material accounting for {approx_equal}40% of the total iron phases. From Moessbauer and X-ray diffraction data it can be deduced that, under the combustion conditions used, new crystalline phases were formed, some of the substitutional Fe{sup 3+} ions existing in the cordierite lattice were reduced to Fe{sup 2+}, and ferric oxides underwent a sintering process which results in hematite with higher particle size. All these findings were detected in the burner zone located in the proximity of the flame and were related to possible chemical reactions which might explain the observed deterioration of the burner material. Research Highlights: {yields}Depth profile analyses used as a probe to understand changes in refractory structure. {yields}All changes take place in the uppermost surface of the burner, close to the flame. {yields}Reduction to Fe{sup 2+} of substitutional Fe{sup 3+} ions and partial cordierite decomposition. {yields}Heating-cooling cycling induces a sintering of the existing iron oxide particles. {yields}Chemical changes can explain the alterations observed in the material microstructure.

  12. Appraisal of BWR plutonium burners for energy centers

    International Nuclear Information System (INIS)

    Williamson, H.E.

    1976-01-01

    The design of BWR cores with plutonium loadings beyond the self-generation recycle (SGR) level is investigated with regard to their possible role as plutonium burners in a nuclear energy center. Alternative plutonium burner approaches are also examined including the substitution of thorium for uranium as fertile material in the BWR and the use of a high-temperature gas reactor (HTGR) as a plutonium burner. Effects on core design, fuel cycle facility requirements, economics, and actinide residues are considered. Differences in net fissile material consumption among the various plutonium-burning systems examined were small in comparison to uncertainties in HTGR, thorium cycle, and high plutonium-loaded LWR technology. Variation in the actinide content of high-level wastes is not likely to be a significant factor in determining the feasibility of alternate systems of plutonium utilization. It was found that after 10,000 years the toxicity of actinide high-level wastes from the plutonium-burning fuel cycles was less than would have existed if the processed natural ores had not been used for nuclear fuel. The implications of plutonium burning and possible future fuel cycle options on uranium resource conservation are examined in the framework of current ERDA estimates of minable uranium resources

  13. Process development report: 0.20-m secondary burner system

    International Nuclear Information System (INIS)

    Rickman, W.S.

    1977-09-01

    HTGR fuel reprocessing consists of crushing the spent fuel elements to a size suitable for burning in a fluidized bed to remove excess graphite; separating, crushing, and reburning the fuel particles to remove the remainder of the burnable carbon; dissolution and separation of the particles from insoluble materials; and solvent extraction separation of the dissolved uranium and thorium. Burning the crushed fuel particles is accomplished in a secondary burner. This is a batch fluidized-bed reactor with in-vessel, off-gas filtration. Process heat is provided by an induction heater. This report documents operational tests performed on a commercial size 0.20-m secondary burner using crushed Fort St. Vrain type TRISO fuel particles. Analysis of a parametric study of burner process variables led to recommending lower bed superficial velocity (0.8 m/s), lower ignition temperature (600 0 C), lower fluid bed operating temperature (850 0 C), lower filter blowback frequency (1 cycle/minute), and a lower fluid bed superficial velocity during final bed burnout

  14. Combustion Characteristics of Butane Porous Burner for Thermoelectric Power Generation

    Directory of Open Access Journals (Sweden)

    K. F. Mustafa

    2015-01-01

    Full Text Available The present study explores the utilization of a porous burner for thermoelectric power generation. The porous burner was tested with butane gas using two sets of configurations: single layer porcelain and a stacked-up double layer alumina and porcelain. Six PbSnTe thermoelectric (TE modules with a total area of 54 cm2 were attached to the wall of the burner. Fins were also added to the cold side of the TE modules. Fuel-air equivalence ratio was varied between the blowoff and flashback limit and the corresponding temperature, current-voltage, and emissions were recorded. The stacked-up double layer negatively affected the combustion efficiency at an equivalence ratio of 0.20 to 0.42, but single layer porcelain shows diminishing trend in the equivalence ratio of 0.60 to 0.90. The surface temperature of a stacked-up porous media is considerably higher than the single layer. Carbon monoxide emission is independent for both porous media configurations, but moderate reduction was recorded for single layer porcelain at lean fuel-air equivalence ratio. Nitrogen oxides is insensitive in the lean fuel-air equivalence ratio for both configurations, even though slight reduction was observed in the rich region for single layer porcelain. Power output was found to be highly dependent on the temperature gradient.

  15. Acoustic Pressure Oscillations Induced in I-Burner

    Science.gov (United States)

    Matsui, Kiyoshi

    Iwama et al. invented the I-burner to investigate acoustic combustion instability in solid-propellant rockets (Proceedings of ICT Conference, 1994, pp. 26-1 26-14). Longitudinal pressure oscillations were induced in the combustion chamber of a thick-walled rocket by combustion of a stepped-perforation grain (I-burner). These oscillations were studied here experimentally. Two I-burners with an internal diameter of 80 mm and a length of 1208 mm or 2240 mm were made. The grain had stepped perforations (20 and 42 mm in diameter and 657 and 160 mm in length, respectively). Longitudinal pressure oscillations always occur in two stages when an HTPB (hydroxyl-terminated polybutadiene)/AP (ammonium perchlorate)/aluminum-powder propellant burns (54 tests; the highest average pressure in the combustion chamber was 9.5 29 MPa), but no oscillations occur when an HTPB/AP propellant burns (29 tests). The pressure oscillations are essentially linear, but dissipation adds a nonlinear nature to them. In the first stage, the amplitudes are small and the first wave group predominates. In the next stage, the amplitudes are large and many wave groups are present. The change in the grain form accompanying the combustion affects the pressure oscillations.

  16. Comparison calculations for an accelerator-driven minor actinide burner

    International Nuclear Information System (INIS)

    2002-01-01

    International interest in accelerator-driven systems (ADS) has recently been increasing in view of the important role that these systems may play as efficient minor actinide and long-lived fission-product (LLFP) burners and/or energy producers with an enhanced safety potential. However, the current methods of analysis and nuclear data for minor actinide and LLFP burners are not as well established as those for conventionally fuelled reactor systems. Hence, in 1999, the OECD/NEA Nuclear Science Committee organised a benchmark exercise for an accelerator-driven minor actinide burner to check the performances of reactor codes and nuclear data for ADS with unconventional fuel and coolant. The benchmark model was a lead-bismuth-cooled subcritical system driven by a beam of 1 GeV protons. This report provides an analysis of the results supplied by seven participants from eight countries. The analysis reveals significant differences in important neutronic parameters, indicating a need for further investigation of the nuclear data, especially minor actinide data, as well as the calculation methods. This report will be of particular interest to reactor physicists and nuclear data evaluators developing nuclear systems for nuclear waste management. (authors)

  17. Shuttle Gaseous Hydrogen Venting Risk from Flow Control Valve Failure

    Science.gov (United States)

    Drummond, J. Philip; Baurle, Robert A.; Gafney, Richard L.; Norris, Andrew T.; Pellett, Gerald L.; Rock, Kenneth E.

    2009-01-01

    This paper describes a series of studies to assess the potential risk associated with the failure of one of three gaseous hydrogen flow control valves in the orbiter's main propulsion system during the launch of Shuttle Endeavour (STS-126) in November 2008. The studies focused on critical issues associated with the possibility of combustion resulting from release of gaseous hydrogen from the external tank into the atmosphere during assent. The Shuttle Program currently assumes hydrogen venting from the external tank will result in a critical failure. The current effort was conducted to increase understanding of the risk associated with venting hydrogen given the flow control valve failure scenarios being considered in the Integrated In-Flight Anomaly Investigation being conducted by NASA.

  18. Particle size control of detergents in mixed flow spray dryers

    Directory of Open Access Journals (Sweden)

    Mark Jonathan Crosby

    2015-03-01

    Full Text Available Particle size is a key quality parameter of a powder detergent as it determines its performance, the bulk density and the look and feel of the product. Consequently, it is essential that particle size is controlled to ensure the consistency of performance when comparing new formulations. The majority of study reported in the literature relating to particle size control, focuses on the spray produced by the atomisation technique. One approach advocated to achieve particle size control is the manipulation of the ratio of the mass slurry rate and mass flow rate of gas used for atomisation. Within this study, ratio control was compared with an automatic cascade loop approach using online measurements of the powder particle size on a small-scale pilot plant. It was concluded that cascade control of the mean particle size, based on manipulating the mass flow rate of gas, resulted in tighter, more responsive control. The effect of a ratio change varied with different formulations and different slurry rates. Furthermore, changes in slurry rate caused complications, as the impact on particle size growth in the dryer is non-linear and difficult to predict. The cascade loop enables further study into the effect of particle size on detergent performance.

  19. Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Choudhuri, Ahsan [Univ. Of Texas, El Paso, TX (United States)

    2013-09-30

    Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO2 from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H2 concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO2 and H2O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient gF) values for CH4-O2-CO2 flames. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH4/21%O2/79%N2 and CH4/38%O2/72%CO2 mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of

  20. Kecepatan Pembakaran Premixed Campuran Minyak Jarak - Liquefied Petroleum Gas (LPG pada Circular Tube Burner

    Directory of Open Access Journals (Sweden)

    Defmit B.N. Riwu

    2016-10-01

    Full Text Available This study was conducted to determine the characteristics of premixed combustion of a mixture of castor oil - LPG on a circular tube burner. Percentage of LPG fuel in a mixture of jatropha curcas oil - LPG varied as much as 10%, 20%, 30%, and 40% of the mass flow jatropha curcas oil vapor. Considering the flame of fire there are two angles formed which describe burning velocity. Also there are formed two cones of fire where the bright blue inside cone is a premixed flame, while the outer blue white cone is flame a diffusion flame. An increase in the percentage of LPG makes the value of top and bottom angle increase. So that the burning velocity on the upper angle decrease whilst on bottom angle increase.

  1. Experimental Evaluation of a Low Emissions High Performance Duct Burner for Variable Cycle Engines (VCE)

    Science.gov (United States)

    Lohmann, R. P.; Mador, R. J.

    1979-01-01

    An evaluation was conducted with a three stage Vorbix duct burner to determine the performance and emissions characteristics of the concept and to refine the configuration to provide acceptable durability and operational characteristics for its use in the variable cycle engine (VCE) testbed program. The tests were conducted at representative takeoff, transonic climb, and supersonic cruise inlet conditions for the VSCE-502B study engine. The test stand, the emissions sampling and analysis equipment, and the supporting flow visualization rigs are described. The performance parameters including the fuel-air ratio, the combustion efficiency/exit temperature, thrust efficiency, and gaseous emissions calculations are defined. The test procedures are reviewed and the results are discussed.

  2. On the instability of a modified cup-burner flame in the infrared spectral region

    Directory of Open Access Journals (Sweden)

    Petr Bitala

    2016-03-01

    Full Text Available This study describes the modification of a standardised cup-burner apparatus. The replacement of the original glass chimney is performed by shielding a nitrogen co-flow enabled measurement at a wavelength of 3.9 μm. This modification, together with a special arrangement of the measuring system (spectral filtering, data acquisition and post-processing, permitted the observation of various types of hydrodynamic instabilities, including transition states. The advantages of our arrangement are demonstrated with an ethylene non-premixed flame with high sooting tendency. Two known modes of hydrodynamic instability (varicose and sinuous that occur in buoyant flames were studied and described quantitatively. Based on the intensity of the infrared emissions, we identified and qualitatively described the modes of periodic hydrodynamic instability that are accompanied by flame tip opening, which has not been observed for this type of flame.

  3. Strategic Management Accounting in Organizations’ Cash Flow Control

    OpenAIRE

    Y. P. Vetrov; O. G. Vandina; A. R. Galustov

    2017-01-01

    The article deals with the various interpretations of the term "strategic management accounting". The role and importance of strategic management accounting in the organization’s cash flows control are investigated. The accounting and analytical models of strategic management accounting are analyzed. The territorial scope of this article covers the Russian Federation. The study concludes that the system of assessment parameters of organization’s financial condition should cover all its aspect...

  4. Experimental control of natural perturbations in channel flow

    OpenAIRE

    Juillet , Fabien; Mckeon , J.; Schmid , Peter J.

    2014-01-01

    International audience; A combined approach using system identification and feed-forward control design has been applied to experimental laminar channel flow in an effort to reduce the naturally occurring disturbance level. A simple blowing/suction strategy was capable of reducing the standard deviation of the measured sensor signal by 45 %, which markedly exceeds previously obtained results under comparable conditions. A comparable reduction could be verified over a significant streamwise ex...

  5. Thermal Mechanisms for High Amplitude Aerodynamic Flow Control (YIP 2012)

    Science.gov (United States)

    2016-04-15

    transport aircraft , much less cruise. The search for a perfect actuator continues, but progress has been limited by the often proprietary nature these...wave generation as a mechanism for high amplitude, high bandwidth actuation has been demonstrated, but the fundamental physics of how this...moving forward with such a definition. 15. SUBJECT TERMS active flow control, energy deposition, plasma actuation 16. SECURITY CLASSIFICATION OF: 17

  6. Industrial opportunities of controlled melt flow during glass melting, part 1: Melt flow evaluation

    Czech Academy of Sciences Publication Activity Database

    Dyrčíková, Petra; Hrbek, Lukáš; Němec, Lubomír

    2014-01-01

    Roč. 58, č. 2 (2014), s. 111-117 ISSN 0862-5468 R&D Projects: GA TA ČR TA01010844 Institutional support: RVO:67985891 Keywords : glass melting * controlled flow * space utilization Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.435, year: 2014 http://www.ceramics-silikaty.cz/2014/pdf/2014_02_111.pdf

  7. Empirical Reduced-Order Modeling for Boundary Feedback Flow Control

    Directory of Open Access Journals (Sweden)

    Seddik M. Djouadi

    2008-01-01

    Full Text Available This paper deals with the practical and theoretical implications of model reduction for aerodynamic flow-based control problems. Various aspects of model reduction are discussed that apply to partial differential equation- (PDE- based models in general. Specifically, the proper orthogonal decomposition (POD of a high dimension system as well as frequency domain identification methods are discussed for initial model construction. Projections on the POD basis give a nonlinear Galerkin model. Then, a model reduction method based on empirical balanced truncation is developed and applied to the Galerkin model. The rationale for doing so is that linear subspace approximations to exact submanifolds associated with nonlinear controllability and observability require only standard matrix manipulations utilizing simulation/experimental data. The proposed method uses a chirp signal as input to produce the output in the eigensystem realization algorithm (ERA. This method estimates the system's Markov parameters that accurately reproduce the output. Balanced truncation is used to show that model reduction is still effective on ERA produced approximated systems. The method is applied to a prototype convective flow on obstacle geometry. An H∞ feedback flow controller is designed based on the reduced model to achieve tracking and then applied to the full-order model with excellent performance.

  8. A FUEL-RICH PRECOMBUSTOR. FIELD EVALUATION OF LOW-EMISSION COAL BURNER TECHNOLOGY ON UTILITY BOILERS - VOLUME IV. ALTERNATE CON- CEPTS FOR SOX, NOX, AND PARTICULATE EMISSIONS CONTROL FROM

    Science.gov (United States)

    The report gives results a study of the use of precombustors for the simultaneous control of S02, NOx, and ash emissions from coal combustion. In Phase 1, exploratory testing was conducted on a small pilot scale--293 kW (million Btu/hr)-pulverized-coal-fired precombustor to ident...

  9. Optical diagnostics to adjust burners. Een optische diagnostiek voor het instellen van branders

    Energy Technology Data Exchange (ETDEWEB)

    Braam, A L.H.; Hulshof, H J.M.; De Jongh, W [NV KEMA, Arnhem (Netherlands)

    1991-05-01

    The most efficient method to reduce nitrogen oxides in a natural gas flame or a coal flame is a correct adjustment of the burners. A newly developed optical method to measure the temperature distribution in the flame is discussed. KEMA (a Dutch Electrotechnical Equipment Testing Agency) developed the measuring method to control the combustion process in each burner of a natural gas- or coal-fired power plant for NOx formation for a constant energy production, and for the stability of the combustion. By means of data from the temperature distribution measurements some important parameters concerning NOx formation can be determined. Attention is paid to several active and passive spectroscopic methods to measure temperatures in flames. Passive spectroscopy is considered to be the best measuring method. Concentrations of radicals (CH, CN, NH) and temperature distribution are determined by means of a spectroheliograph and a camera, flame temperatures are measured by means of metal tracers. Experimental measurements carried out in the Flevo plant (EPON) are discussed. 8 figs.

  10. A Metal Fuel Core Concept for 1000 MWt Advanced Burner Reactor

    International Nuclear Information System (INIS)

    Yang, W.S.; Kim, T.K.; Grandy, C.

    2007-01-01

    This paper describes the core design and performance characteristics of a metal fuel core concept for a 1000 MWt Advanced Burner Reactor. A ternary metal fuel form of U-TRU-Zr was assumed with weapons grade plutonium feed for the startup core and TRU recovered from LWR spent fuel for the recycled equilibrium core. A compact burner core was developed by trade-off between the burnup reactivity loss and TRU conversion ratio, with a fixed cycle length of one-year. In the startup core, the average TRU enrichment is 15.5%, the TRU conversion ratio is 0.81, and the burnup reactivity loss over a cycle is 3.6% Δk. The heavy metal and TRU inventories are 13.1 and 2.0 metric tons, respectively. The average discharge burnup is 93 MWd/kg, and the TRU consumption rate is 55.5 kg/year. For the recycled equilibrium core, the average TRU enrichment is 22.1 %, the TRU conversion ratio is 0.73, and the burnup reactivity loss is 2.2% Δk. The TRU inventory and consumption rate are 2.9 metric tons and 81.6 kg/year, respectively. The evaluated reactivity coefficients provide sufficient negative feedbacks. The control systems provide shutdown margins that are more than adequate. The integral reactivity parameters for quasi-static reactivity balance analysis indicate favorable passive safety features, although detailed safety analyses are required to verify passive safety behavior. (authors)

  11. Evaluation of steady flow torques and pressure losses in a rotary flow control valve by means of computational fluid dynamics

    International Nuclear Information System (INIS)

    Okhotnikov, Ivan; Noroozi, Siamak; Sewell, Philip; Godfrey, Philip

    2017-01-01

    Highlights: • A novel design of a rotary flow control valve driven by a stepper motor is proposed. • The intended use of the valve in the high flow rate independent metering hydraulic system is suggested. • Pressure drops, steady flow torques of the valve for various flow rates and orifice openings are studied by means of computational fluid dynamics. • The discharge coefficient and flow jet angles dependencies on the orifice opening are obtained. • A design method to decrease the flow forces without reducing the flow rate in single-staged valves is demonstrated. - Abstract: In this paper, a novel design of a rotary hydraulic flow control valve has been presented for high flow rate fluid power systems. High flow rates in these systems account for substantial flow forces acting on the throttling elements of the valves and cause the application of mechanically sophisticated multi-staged servo valves for flow regulation. The suggested design enables utilisation of single-stage valves in power hydraulics operating at high flow rates regimes. A spool driver and auxiliary mechanisms of the proposed valve design were discussed and selection criteria were suggested. Analytical expressions for metering characteristics as well as steady flow torques have been derived. Computational fluid dynamics (CFD) analysis of steady state flow regimes was conducted to evaluate the hydraulic behaviour of the proposed valve. This study represents a special case of an independent metering concept applied to the design of power hydraulic systems with direct proportional valve control operating at flow rates above 150 litres per minute. The result gained using parametric CFD simulations predicted the induced torque and the pressure drops due to a steady flow. Magnitudes of these values prove that by minimising the number of spool's mobile metering surfaces it is possible to reduce the flow-generated forces in the new generation of hydraulic valves proposed in this study

  12. Modification of Flow Structure Over a Van Model By Suction Flow Control to Reduce Aerodynamics Drag

    Directory of Open Access Journals (Sweden)

    Harinaldi Harinaldi

    2012-05-01

    Full Text Available Automobile aerodynamic studies are typically undertaken to improve safety and increase fuel efficiency as well as to  find new innovation in automobile technology to deal with the problem of energy crisis and global warming. Some car companies have the objective to develop control solutions that enable to reduce the aerodynamic drag of vehicle and  significant modification progress is still possible by reducing the mass, rolling friction or aerodynamic drag. Some flow  control method provides the possibility to modify the flow separation to reduce the development of the swirling structures around the vehicle. In this study, a family van is modeled with a modified form of Ahmed's body by changing the orientation of the flow from its original form (modified/reversed Ahmed body. This model is equipped with a suction on the rear side to comprehensively examine the pressure field modifications that occur. The investigation combines computational and experimental work. Computational approach used  a commercial software with standard k-epsilon flow turbulence model, and the objectives was  to determine the characteristics of the flow field and aerodynamic drag reduction that occurred in the test model. Experimental approach used load cell in order to validate the aerodynamic drag reduction obtained by computational approach. The results show that the application of a suction in the rear part of the van model give the effect of reducing the wake and the vortex formation. Futhermore, aerodynamic drag reduction close to 13.86% for the computational approach and 16.32% for the experimental have been obtained.

  13. A flow-control mechanism for distributed systems

    Science.gov (United States)

    Maitan, J.

    1991-01-01

    A new approach to the rate-based flow control in store-and-forward networks is evaluated. Existing methods display oscillations in the presence of transport delays. The proposed scheme is based on the explicit use of an embedded dynamic model of a store-and-forward buffer in a controller's feedback loop. It is shown that the use of the model eliminates the oscillations caused by the transport delays. The paper presents simulation examples and assesses the applicability of the scheme in the new generation of high-speed photonic networks where transport delays must be considered.

  14. Control of energy flow in residential buildings; Energieflussregelung in Wohngebaeuden

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, Martin

    2011-07-01

    Energy systems in residential buildings are changing from monovalent, combustion based systems to multivalent systems containing technologies such as solar collectors, pellet boilers, heat pumps, CHP and multiple storages. Multivalent heat and electricity generation and additional storages raise the number of possible control signals in the system. This creates additional degrees of freedom regarding the choice of the energy converter and the instant of time for energy conversion. New functionality of controllers such as prioritisation of energy producers, optimization of electric self consumption and control of storages and energy feed-in are required. Within the scope of this thesis, new approaches for demand-driven optimal control of energy flows in multivalent building energy systems are developed and evaluated. The approaches are evaluated by means of system energy costs and operating emissions. For parametrisation of the controllers an easily understandable operating concept is developed. The energy flow controllers are implemented as a multi agent system (MAS) and a nonlinear model predictive controller (MPC). Proper functionality and stability are demonstrated in simulations of two example energy systems. In both example systems the MPC controller achieves less energy costs and operating emissions due to system wide global optimization and the more detailed system model within the controller. The multi agent approach turns out to perform better for systems with a huge number of components, e.g. in home automation and energy management systems. Due to the good performance of the reference control strategies, a significant reduction of energy costs and operating emissions is only possible with limitations. Systems for heat generation show only an especially low potential for optimization because of marginal variation ins heat production costs. The adaptation of the operation mode to user priorities, changing utilization characteristics and dynamic energy

  15. CRITICAL CONTROL POINTS ON THE TECHNOLOGICAL FLOW OF PANIFICATION

    Directory of Open Access Journals (Sweden)

    Gigel PARASCHIV

    2013-05-01

    Full Text Available Bread and panification products are intended for direct human consumption and underlying nutritional pyramid, it can affect the consumers health in case of biological, chemical or physical contamination, immediate or delayed, by noxious accumulation in the human organism. Only by rigorous compliance of the production rules throughout the technological process can ensure the quality and food safety of these products. If the risk can be prevented, eliminated or reduce to an acceptable level, as a result of a control actions made at that stage, it is considered a Critical Control Point (CCP. There can be checkpoints where it can exert a control action. Thus, the checkpoint is represented by any stage in which the risk factors, biological, chemical or physical, can be controlled in order to prevent, disrupt or reduce them to an acceptable level. This paper is referring to the control points on the technological flow of the bread fabrication, in all phases of this technological flow, laying stress on that points (or phases which can affect security and food safety, through the influence of parameters of any kind on the quality of finished products.

  16. Multifuel burners based on the porous burner technology for the application in fuel cell systems; Mehrstofffaehige Brenner auf Basis der Porenbrennertechnik fuer den Einsatz in Brennstoffzellensystemen

    Energy Technology Data Exchange (ETDEWEB)

    Diezinger, S.

    2006-07-01

    The present doctoral thesis describes the development of multifuel burners based on the porous burner technology for the application in hydrocarbon driven fuel cell systems. One objective of such burners is the heating of the fuel cell system to the operating temperature at the cold start. In stationary operation the burner has to postcombust the waste gases from the fuel cell and the gas processing system in order to reduce the pollutant emissions. As the produced heat is required for endothermal processes like the steam reforming the burner has a significant influence on the system's efficiency. The performed investigations are targeting on a gasoline driven PEMFC-System with steam reforming. In such systems the burner has to be capable to combust the system's fuel gasoline at the cold start, a low calorific fuel cell offgas (HU = 6,4 MJ/kg) in stationary operation and a hydrogen rich gas in the case of an emergency shut down. Pre-tests revealed that in state of the art porous burners the flame front of hydrogen/air combustion can only be stabilized at very high excess air ratios. In basic investigations concerning the stabilization of flame fronts in porous media the dominant influence parameters were determined. Based on this findings a new flame trap was developed which increases the operational range with hydrogen rich mixtures significantly. Furthermore the burning velocity at stationary combustion in porous media was investigated. The dependency of the porous burning velocity on the excess air ratio for different hydrocarbons and hydrogen as well as for mixtures of both was determined. The results of these basic investigations were applied for the design of a multifuel burner. In order to achieve an evaporation of the gasoline without the use of additional energy, an internal heat exchanger section for heating the combustion air was integrated into the burner. Additionally different experimental and numerical methods were applied for designing the

  17. Neural Network Predictive Control for Vanadium Redox Flow Battery

    Directory of Open Access Journals (Sweden)

    Hai-Feng Shen

    2013-01-01

    Full Text Available The vanadium redox flow battery (VRB is a nonlinear system with unknown dynamics and disturbances. The flowrate of the electrolyte is an important control mechanism in the operation of a VRB system. Too low or too high flowrate is unfavorable for the safety and performance of VRB. This paper presents a neural network predictive control scheme to enhance the overall performance of the battery. A radial basis function (RBF network is employed to approximate the dynamics of the VRB system. The genetic algorithm (GA is used to obtain the optimum initial values of the RBF network parameters. The gradient descent algorithm is used to optimize the objective function of the predictive controller. Compared with the constant flowrate, the simulation results show that the flowrate optimized by neural network predictive controller can increase the power delivered by the battery during the discharge and decrease the power consumed during the charge.

  18. Digital feedwater and recirculation flow control for GPUN Oyster Creek

    International Nuclear Information System (INIS)

    Burjorjee, D.; Gan, B.

    1992-01-01

    This paper describes the digital system for feedwater and recirculation control that GPU Nuclear will be installing at Oyster Creek during its next outage - expected circa December 1992. The replacement was motivated by considerations of reliability and obsolescence - the analog equipment was aging and reaching the end of its useful life. The new system uses Atomic Energy of Canada Ltd.'s software platform running on dual, redundant, industrial-grade 386 computers with opto-isolated field input/output (I/O) accessed through a parallel bus. The feedwater controller controls three main feed regulating valves, two low flow regulating valves, and two block valves. The recirculation controller drives the five scoop positioners of the hydraulic couplers. The system also drives contacts that lock up the actuators on detecting an open circuit in their current loops

  19. Proportional feedback control of laminar flow over a hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Il [Dept. of Mechanical Engineering, Ajou University, Suwon (Korea, Republic of); Son, Dong Gun [Severe Accident and PHWR Safety Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon (Korea, Republic of)

    2016-08-15

    In the present study, we perform a proportional feedback control of laminar flow over a hemisphere at Re = 300 to reduce its lift fluctuations by attenuating the strength of the vortex shedding. As a control input, blowing/suction is distributed on the surface of hemisphere before the separation, and its strength is linearly proportional to the transverse velocity at a sensing location in the centerline of the wake. The sensing location is determined based on a correlation function between the lift force and the time derivative of sensing velocity. The optimal proportional gains for the proportional control are obtained for the sensing locations considered. The present control successfully attenuates the velocity fluctuations at the sensing location and three dimensional vertical structures in the wake, resulting in the reduction of lift fluctuations of hemisphere.

  20. Nitrogen oxide suppression by using a new design of pulverized-coal burners

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Cameron, S.D.; Grekhov, L.L. [All-Russian Thermal Engineering Institute, Moscow (Russian Federation)

    1996-07-01

    The results of testing a low-NO{sub x} swirl burner are presented. This burner was developed by Babcock Energy Ltd., for reducing nitrogen oxide emissions when burning Ekibastuz and Kuznetsk low-caking coals in power boilers. The tests conducted at a large plant of the BEL Technological Center showed that the new burner reduces NO{sub x} emissions by approximately two times. 6 refs., 6 figs., 1 tab.

  1. "Batch" kinetics in flow: online IR analysis and continuous control.

    Science.gov (United States)

    Moore, Jason S; Jensen, Klavs F

    2014-01-07

    Currently, kinetic data is either collected under steady-state conditions in flow or by generating time-series data in batch. Batch experiments are generally considered to be more suitable for the generation of kinetic data because of the ability to collect data from many time points in a single experiment. Now, a method that rapidly generates time-series reaction data from flow reactors by continuously manipulating the flow rate and reaction temperature has been developed. This approach makes use of inline IR analysis and an automated microreactor system, which allowed for rapid and tight control of the operating conditions. The conversion/residence time profiles at several temperatures were used to fit parameters to a kinetic model. This method requires significantly less time and a smaller amount of starting material compared to one-at-a-time flow experiments, and thus allows for the rapid generation of kinetic data. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Flue gas recirculation to pellets burner

    International Nuclear Information System (INIS)

    Loefgren, B.E.; Blohm, T.

    1999-05-01

    The aim of this project has been to study the influence of flue gas recirculation on the combustion results. Primarily regarding the turbulence, stability and air surplus of the flame, but also the influence on environmental factors (CO and unburnt hydrocarbons). Also studied was the possibility of automatic control of the mixing of recirculating flue gases in the combustion process through the use of a λ-sond and O 2 control Project report from the program: Small scale combustion of biofuels. 9 figs, 8 tabs

  3. Participative planning and information flow within management control

    Directory of Open Access Journals (Sweden)

    Tomasz Dyczkowski

    2016-09-01

    Full Text Available The paper examines the relationships between two different approaches to planning processes (participa- tive and non-participative and information flows within management control in companies. It augments the existing theoretical and empirical research by coupling management control and management infor- mation with participative planning, not only in operational but also in the strategic perspective. The re- sults presented in the paper stem from two consecutive studies, conducted between November 2010 and January 2012 and between November 2013 and January 2014. The studies comprised 397 and 179 Polish companies respectively. The authors formulated two hypotheses linking participative planning with upward and downward management information flows. The paper employed a quantitative approach, using the Spearman rank correlation analysis and hierarchical clustering using the Ward method, which enabled comparative analyses both in reference to various groups of companies included in particular research samples and over time. The results obtained showed the positive influence of participative plan- ning both on upward and downward information flows in enterprises. In particular, participative planning reduced information imbalances between top (the management and lower (employees of functional departments tiers in organisation structures.

  4. Development of the flow control irradiation facility for JOYO

    International Nuclear Information System (INIS)

    Soroi, Masatoshi; Miyakawa, Shun-ichi

    1998-05-01

    This report describes the present situation and problems with the development of the flow control irradiation facility (FLORA). The purpose of FLORA is to run the cladding breach (RTCB) irradiation test under loss of flow conditions in the experimental fast reactor 'JOYO'. FLORA is a facility like FPTF (Fuel Performance Test Facility) plus BFTF (Breached Fuel Test Facility) in EBR-II, USA. The technical feature of FLORA is its annular linear induction pump (A-LIP), which was developed in response to a need identified through the experiences in the mechanical flow control of FPTF. We have already designed the basic system facility of FLORA for the JOYO MK-II core. However, to put FLORA to practical use in the future, we have to confirm the stability of the JOYO MK-III core condition, solve problems and improve the design. We are going to freeze and review the FLORA project, taking into consideration the fuel development situation and the research project of JOYO MK-III core. (J.P.N.)

  5. Drag reduction in channel flow using nonlinear control

    Science.gov (United States)

    Keefe, Laurence R.

    1993-01-01

    Two nonlinear control schemes have been applied to the problem of drag reduction in channel flow. Both schemes have been tested using numerical simulations at a mass flux Reynolds numbers of 4408, utilizing 2D nonlinear neutral modes for goal dynamics. The OGY-method, which requires feedback, reduces drag to 60-80 percent of the turbulent value at the same Reynolds number, and employs forcing only within a thin region near the wall. The H-method, or model-based control, fails to achieve any drag reduction when starting from a fully turbulent initial condition, but shows potential for suppressing or retarding laminar-to-turbulent transition by imposing instead a transition to a low drag, nonlinear traveling wave solution to the Navier-Stokes equation. The drag in this state corresponds to that achieved by the OGY-method. Model-based control requires no feedback, but in experiments to date has required the forcing be imposed within a thicker layer than the OGY-method. Control energy expenditures in both methods are small, representing less than 0.1 percent of the uncontrolled flow's energy.

  6. Control of open end plasma flow utilizing orbital stochasticity

    International Nuclear Information System (INIS)

    Hojo, Hitoshi

    1995-01-01

    It has been known that the control of plasma outside the confinement region of diverter plasma and others in a magnetic field confinement device is very important for improveing the confinement of bulk plasma. The control of plasma outside a confinement region bears two roles, one is the reduction of the thermal load on a diverter plate and others due to the plasma particles lost from the confinement region, and another is the restriction of the back flow of cold plasma and impurities generated outside the confinement region to a bulk plasma region. In this study, the new method of controlling plasma outside a confinement region called magnetic diverter is considered. To the plasma particles advancing along magnetic force lines, the reflection and capture of the plasma particles occur in the region of orbital stochasticity, and the thermal load on an end plate and the reverse flow to a bulk plasma region are restricted. The numerical computation model used regarding the particle control utilizing the orbital stochasticity and the results of calculating the orbit of plasma particles in a magnetic field are reported. (K.I.)

  7. Synthetic Jets Flow Control on a vertical stabilizer

    Science.gov (United States)

    Rathay, Nicholas; Boucher, Matthew; Amitay, Michael

    2011-11-01

    The vertical stabilizer on most commercial transport aircraft is much larger than required for stability and control. The tail is significantly oversized in order to maintain controllability in the event of asymmetric engine failure and meet flying qualities requirements related to dynamic motion. Using aerodynamic flow control techniques, it may be possible to reduce the size of the tail while maintaining similar control authority during inclement flight conditions. Reducing the size of the tail decreases the weight and the drag of the airplane, which results in considerable savings in fuel costs. In this work, it is shown that synthetic jet (zero-net-mass-flux) actuators are capable of reattaching the separated flow on the rudder and augmenting the performance of the stabilizer. Experiments were conducted in an open-return wind tunnel on a 1/25th scale model of a vertical stabilizer and a partial fuselage section. The surface pressure, aerodynamic loads and data acquired with a Stereo PIV system were used to investigate the effectiveness of this technology as well as provide a more detailed analysis of the flowfield and showed that the synthetic jets are capable of augmenting the side-force by up to 20%.

  8. Flow controls on lowland river macrophytes: a review.

    Science.gov (United States)

    Franklin, Paul; Dunbar, Michael; Whitehead, Paul

    2008-08-01

    We review the current status of knowledge regarding the role that flow parameters play in controlling the macrophyte communities of temperate lowland rivers. We consider both direct and indirect effects and the interaction with other factors known to control macrophyte communities. Knowledge gaps are identified and implications for the management of river systems considered. The main factors and processes controlling the status of macrophytes in lowland rivers are velocity (hence also discharge), light, substrate, competition, nutrient status and river management practices. We suggest that whilst the characteristics of any particular macrophyte community reflect the integral effects of a combination of the factors, fundamental importance can be attributed to the role of discharge and velocity in controlling instream macrophyte colonisation, establishment and persistence. Velocity and discharge also appear to control the relative influence of some of the other controlling factors. Despite the apparent importance of velocity in determining the status of macrophyte communities in lowland rivers, relatively little is understood about the nature of the processes controlling this relationship. Quantitative knowledge is particularly lacking. Consequently, the ability to predict macrophyte abundance and distribution in rivers is still limited. This is further complicated by the likely existence of feedback effects between the growth of macrophytes and velocity. Demand for water resources increases the pressure on lowland aquatic ecosystems. Despite growing recognition of the need to allocate water for the needs of instream biota, the inability to assess the flow requirements of macrophyte communities limits the scope to achieve this. This increases the likelihood of overexploitation of the water resource as other users, whose demands are quantifiable, are prioritised.

  9. Unsteady flow model for circulation-control airfoils

    Science.gov (United States)

    Rao, B. M.

    1979-01-01

    An analysis and a numerical lifting surface method are developed for predicting the unsteady airloads on two-dimensional circulation control airfoils in incompressible flow. The analysis and the computer program are validated by correlating the computed unsteady airloads with test data and also with other theoretical solutions. Additionally, a mathematical model for predicting the bending-torsion flutter of a two-dimensional airfoil (a reference section of a wing or rotor blade) and a computer program using an iterative scheme are developed. The flutter program has a provision for using the CC airfoil airloads program or the Theodorsen hard flap solution to compute the unsteady lift and moment used in the flutter equations. The adopted mathematical model and the iterative scheme are used to perform a flutter analysis of a typical CC rotor blade reference section. The program seems to work well within the basic assumption of the incompressible flow.

  10. Device for controlling a recirculation flow in a reactor

    International Nuclear Information System (INIS)

    Shida, Toichi; Tohei, Kazushige; Hirose, Masao; Nakamura, Hideo.

    1976-01-01

    Object: To provide an emergency cut-off valve in a recirculation system in a reactor to control the recirculation at the time of turbine trip or load cut-off, thereby relieving excessive increase in heat output of fuel. Structure: A recirculation pump is driven through a recirculation pump motor by an AC generator, which is driven by a driving motor through a fluid coupling, so that reactor water passes the emergency cut-off valve and recirculation flow stop valve and then passes a jet pump into the core. At the time of turbine trip or load cut-off, the emergency cut-off valve is closed by a hydraulic circuit, whereby core flow is merely decreased by 20 to 30% in a short period of time to restrain excessive increase in heat output. (Yoshino, Y.)

  11. Cerebral autoregulation control of blood flow in the brain

    CERN Document Server

    Payne, Stephen

    2016-01-01

    This Brief provides a comprehensive introduction to the control of blood flow in the brain. Beginning with the basic physiology of autoregulation, the author goes on to discuss measurement techniques, mathematical models, methods of analysis, and relevant clinical conditions, all within this single volume. The author draws together this disparate field, and lays the groundwork for future research directions. The text gives an up-to-date review of the state of the art in cerebral autoregulation, which is particularly relevant as cerebral autoregulation moves from the laboratory to the bedside. Cerebral Autoregulation will be useful to researchers in the physical sciences such as mathematical biology, medical physics, and biomedical engineering whose work is concerned with the brain. Researchers in the medical sciences and clinicians dealing with the brain and blood flow, as well as industry professionals developing techniques such as ultrasound, MRI, and CT will also find this Brief of interest.

  12. Computing an operating parameter of a unified power flow controller

    Science.gov (United States)

    Wilson, David G.; Robinett, III, Rush D.

    2017-12-26

    A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.

  13. Computing an operating parameter of a unified power flow controller

    Science.gov (United States)

    Wilson, David G; Robinett, III, Rush D

    2015-01-06

    A Unified Power Flow Controller described herein comprises a sensor that outputs at least one sensed condition, a processor that receives the at least one sensed condition, a memory that comprises control logic that is executable by the processor; and power electronics that comprise power storage, wherein the processor causes the power electronics to selectively cause the power storage to act as one of a power generator or a load based at least in part upon the at least one sensed condition output by the sensor and the control logic, and wherein at least one operating parameter of the power electronics is designed to facilitate maximal transmittal of electrical power generated at a variable power generation system to a grid system while meeting power constraints set forth by the electrical power grid.

  14. Multiphase flow dynamics and control; Dynamique et controle des ecoulements polyphasiques

    Energy Technology Data Exchange (ETDEWEB)

    Duret, E.

    2005-02-01

    Production in the petroleum industry requires a better knowledge of multiphase flow, as the design of pipelines may cause the flow to become strongly unstable. For instance, for low flow rates and when a sea line ends at a riser, the riser base may accumulate liquid and stop the flow of gas. Then, the upstream gas is compressed until its pressure is large enough to push the liquid slug downstream. Under such conditions, a cyclic process occurs which is called severe slugging, generating large and fast fluctuations in pressure and flow rates. This thesis is devoted to two methods to stabilize this undesirable phenomenon. Using the pipeline's ability to separate phases to pick-up the gas upstream the riser base, they are mainly based on the perturbation theory (fast proportional effect, slow integral effect). The first one uses a secondary riser to transport the gas to the surface facilities. A stability study worked out with the phase diagrams technique shows that it is a good method to control this phenomenon. However, it imposes a high pressure in all the system. Thus, the second controller re-injects the gas at a determined height in the riser to decrease the hydrostatic pressure. A first stability study in open loop give a criterion on the minimal reinjection height. Then, the controller is developed by using the two-time scale control techniques. Finally, let us denote that these two controllers have been validated with a small size experimental set up. (author)

  15. Pollutant Concentrations and Emission Rates from Scripted Natural Gas Cooking Burner Use in Nine Northern California Homes

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lorenzetti, David M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Maddalena, Randy L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-10-01

    in the kitchen and bedroom of several homes. A hood with large capture volume and a measured flow of 108 L/s reduced concentrations 80-95%. IMPLICATIONS: These measurements demonstrate that operation of natural gas cooking burners without venting can cause short-term kitchen concentrations of NO2 to exceed the US outdoor health standard, and can elevate concentrations of NO, NO2, and ultrafine particles throughout the home. Results are generally consistent with a recent simulation study that estimated widespread 1h NO2 exposures exceeding 100 ppb in homes that use gas burners without venting. While operating a venting range hood can greatly reduce pollutant levels from burner use (and presumably from cooking as well), performance varies widely across hoods. Increased awareness of the need to ventilate when cooking would substantially reduce in-home exposure to NO2 and ultrafine particles in California homes. Helping consumers select effective hoods, for example by publishing capture efficiency performance ratings, also would help reduce exposure.

  16. A nuclear data acquisition system flow control model

    International Nuclear Information System (INIS)

    Hack, S.N.

    1988-01-01

    A general Petri Net representation of a nuclear data acquisition system model is presented. This model provides for the unique requirements of a nuclear data acquisition system including the capabilities of concurrently acquiring asynchronous and synchronous data, of providing multiple priority levels of flow control arbitration, and of permitting multiple input sources to reside at the same priority without the problem of channel lockout caused by a high rate data source. Finally, a previously implemented gamma camera/physiological signal data acquisition system is described using the models presented

  17. Systematic realisation of control flow analyses for CML

    DEFF Research Database (Denmark)

    Gasser, K.L.S.; Nielson, Flemming; Nielson, Hanne Riis

    1997-01-01

    We present a methodology for the systematic realisation of control flow analyses and illustrate it for Concurrent ML. We start with an abstract specification of the analysis that is next proved semantically sound with respect to a traditional small-step operational semantics; this result holds......) to be defined in a syntax-directed manner, and (iii) to generate a set of constraints that subsequently can be solved by standard techniques. We prove equivalence results between the different versions of the analysis; in particular it follows that the least solution to the constraints generated...

  18. Metabolic control of muscle blood flow during exercise in humans

    DEFF Research Database (Denmark)

    Boushel, Robert Christopher

    2003-01-01

    that combined blockade of NOS and PGI2, and NOS and cytochrome P450, both attenuate exercise-induced hyperemia in humans. Combined vasodilator blockade studies offer the potential to uncover important interactions and compensatory vasodilator responses. The signaling pathways that link metabolic events evoked...... to exert control of muscle vasodilation. Adenosine, nitric oxide (NO), prostacyclin (PGI2), and endothelial-derived hyperpolarization factor (EDHF) are possible mediators of muscle vasodilation during exercise. In humans, adenosine has been shown to contribute to functional hyperemia as blood flow...... by muscle contraction to vasodilatory signals in the local vascular bed remains an important area of study....

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

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang, E-mail: ligang@iet.cn [Key laboratory of light duty gas turbine, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Jiang, Xi [School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS (United Kingdom); Zhao, Yujun [School of Mechanism, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Liu, Cunxi [Key laboratory of light duty gas turbine, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China); Chen, Qi [School of Mechanism, Electronic and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China); Xu, Gang; Liu, Fuqiang [Key laboratory of light duty gas turbine, Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190 (China)

    2017-04-04

    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. - Highlights: • The discharge does not ignite the mixture nor does it induce flashback. • The prominent advantage of this novel plasma swirler is its swirl number adjustable without any mechanical movement. • The frequency of the plasma swirler is adjustable. • The plasma swirler can be used as an oscillator to the reactants. • The plasma swirler can be used alone or combine with other traditional swirlers.

  20. The role of pair dispersion in turbulent flow

    DEFF Research Database (Denmark)

    Bourgoin, M.; Ouellette, N.T.; Xu, H.T.

    2006-01-01

    Mixing and transport in turbulent flows - which have strong local concentration fluctuations - essential in many natural and industrial systems including reactions in chemical mixers, combustion in engines and burners, droplet formation in warm clouds, and biological odor detection and chemotaxis...

  1. The effect of control parameters to the quality of small-scale wood pellet combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ruusunen, M. (Oulu Univ. (Finland). Contol Engineering Lab.), Email: mika.ruusunen@oulu.fi; Korpela, T.; Bjoerkqvist, T. (Tampere Univ. of Technology (Finland). Dept. of Automation Science and Engineering), Email: timo.korpela@tut.fi, Email: tomas.bjorqvist@tut.fi

    2009-07-01

    The target is to clear out control variables and requirements for clean small-scale wood pellet combustion (<100 kW{sub th}). Experimental runs were carried out in the form of design of experiments (DOE) with two commercial 15 kW pellet burners, namely a horizontal gas-burner and a conventional horizontal burner in a 20 kW commercial pellet boiler. Analysed variables were fuel power, draught, air flows, and fuel feed period, and research variables were CO, O{sub 2} and efficiency. The target was to identify and characterise separately the magnitude and direction of the effect of each factor. After process identification and variable optimisation, the results show strong influence of the studied control parameters on the efficiency and the emissions. The effects and interactions between different process variables were rather similar with both burners. The major effects for CO levels were fuel feed and additionally draught affected in case of wood gas combustion. Additionally, the effects on combustion efficiency is described by draught, air feed and fuel feed period. Furthermore, the fuel feed period affected the excess air level in case of direct combustion principle. It was noticed, however, that the combustion properties and optimal parameter values vary significantly between the two cases. (orig.)

  2. Simulation Results of Closed Loop Controlled Interline Power Flow Controller System

    Directory of Open Access Journals (Sweden)

    P. USHA RANI

    2016-01-01

    Full Text Available The Interline Power Flow Controller (IPFC is the latest generation of Flexible AC Transmission Systems (FACTS devices which can be used to control power flows of multiple transmission lines. A dispatch strategy is proposed for an IPFC operating at rated capacity, in which the power circulation between the two series converters is used as the parameter to optimize the voltage profile and power transfer. Voltage stability curves for test system are shown to illustrate the effectiveness of this proposed strategy. In this paper, a circuit model for IPFC is developed and simulation of interline power flow controller is done using the proposed circuit model. Simulation is done using MATLAB simulink and the results are presented.

  3. Device for passive flow control around vertical axis marine turbine

    Science.gov (United States)

    Coşoiu, C. I.; Georgescu, A. M.; Degeratu, M.; Haşegan, L.; Hlevca, D.

    2012-11-01

    The power supplied by a turbine with the rotor placed in a free stream flow may be increased by augmenting the velocity in the rotor area. The energy of the free flow is dispersed and it may be concentrated by placing a profiled structure around the bare turbine in order to concentrate more energy in the rotor zone. At the Aerodynamic and Wind Engineering Laboratory (LAIV) of the Technical University of Civil Engineering of Bucharest (UTCB) it was developed a concentrating housing to be used for hydro or aeolian horizontal axis wind turbines, in order to increase the available energy in the active section of turbine rotor. The shape of the concentrating housing results by superposing several aero/hydro dynamic effects, the most important being the one generated by the passive flow control devices that were included in the housing structure. Those concentrating housings may be also adapted for hydro or aeolian turbines with vertical axis. The present paper details the numerical research effectuated at the LAIV to determine the performances of a vertical axis marine turbine equipped with such a concentrating device, in order to increase the energy quantity extracted from the main flow. The turbine is a Darrieus type one with three vertical straight blades, symmetric with respect to the axis of rotation, generated using a NACA4518 airfoil. The global performances of the turbine equipped with the concentrating housing were compared to the same characteristics of the bare turbine. In order to validate the numerical approach used in this paper, test cases from the literature resulting from experimental and numerical simulations for similar situations, were used.

  4. Device for passive flow control around vertical axis marine turbine

    International Nuclear Information System (INIS)

    Coşoiu, C I; Georgescu, A M; Degeratu, M; Haşegan, L; Hlevca, D

    2012-01-01

    The power supplied by a turbine with the rotor placed in a free stream flow may be increased by augmenting the velocity in the rotor area. The energy of the free flow is dispersed and it may be concentrated by placing a profiled structure around the bare turbine in order to concentrate more energy in the rotor zone. At the Aerodynamic and Wind Engineering Laboratory (LAIV) of the Technical University of Civil Engineering of Bucharest (UTCB) it was developed a concentrating housing to be used for hydro or aeolian horizontal axis wind turbines, in order to increase the available energy in the active section of turbine rotor. The shape of the concentrating housing results by superposing several aero/hydro dynamic effects, the most important being the one generated by the passive flow control devices that were included in the housing structure. Those concentrating housings may be also adapted for hydro or aeolian turbines with vertical axis. The present paper details the numerical research effectuated at the LAIV to determine the performances of a vertical axis marine turbine equipped with such a concentrating device, in order to increase the energy quantity extracted from the main flow. The turbine is a Darrieus type one with three vertical straight blades, symmetric with respect to the axis of rotation, generated using a NACA4518 airfoil. The global performances of the turbine equipped with the concentrating housing were compared to the same characteristics of the bare turbine. In order to validate the numerical approach used in this paper, test cases from the literature resulting from experimental and numerical simulations for similar situations, were used.

  5. Safety aspects of Particle Bed Reactor plutonium burner system

    International Nuclear Information System (INIS)

    Powell, J.R.; Ludewig, H.; Todosow, M.

    1993-01-01

    An assessment is made of the safety aspects peculiar to using the Particle Bed Reactor (PBR) as the burner in a plutonium disposal system. It is found that a combination of the graphitic fuel, high power density possible with the PBR and engineered design features results in an attractive concept. The high power density potentially makes it possible to complete the plutonium burning without requiring reprocessing and remanufacturing fuel. This possibility removes two hazardous steps from a plutonium burning complex. Finally, two backup cooling systems depending on thermo-electric converters and heat pipes act as ultimate heat removal sinks in the event of accident scenarios which result in loss of fuel cooling

  6. Inherent safe fast breeder reactors and actinide burners, metallic fuel

    International Nuclear Information System (INIS)

    Dorner, S.; Schumacher, G.

    1991-04-01

    Nuclear power without breeder strategy uses the possibilities for the energy supply only to a small extend compared to the possibilities of fast breeder reactors, which offer an energy supply for thousands of years. Moreover, a fast neutron device offers the opportunity to run an actinide-burner that could improve the situation of waste management. Within this concept metallic fuel could play a key role. The present report shows some important aspects of the concept like the pyrometallic reprocessing, the behaviour of metallic fuel during a core meltdown accident and others. The report should contribute to the discussion of these problems and initialize further work

  7. Operational limits of recuperative low NO{sub x}-burners using low calorific gas qualities; Einsatzgrenzen rekuperativer Low NO{sub x}-Brenner im Betrieb mit niederkalorischen Gasen

    Energy Technology Data Exchange (ETDEWEB)

    Moentmann, Dirk; Kleingries, Mirko; Pohland vom Schloss, Heide; Lucka, Klaus [OWI Oel-Waerme-Institut GmbH, An-Institut der RWTH, Aachen (Germany)

    2011-06-15

    The by products of several industrial processes are gases with lower calorific value. Rising energy prices make them a focus of interest for thermal utilization. The combuston of low calorific value gases is demanding with respect to the combustion process. The chemical composition varies depending on the application and process flow. A stable combustion has to be ensured at any time in spite of fluctuating properties like calorific value, wobbe index, flame temperature etc. Corrosive components may induce degradation of sealing materials employed in devices of the burner equipment like shut off valves. Within this research project of the research association 'Forschungsgemeinschaft Industrieofenbau (FOGI)' the operation and ignition behaviour of three commercial recuperator burners was investigated under operation with low calorific gases. It is demonstrated that these burners can basically be deployed under certain conditions. (orig.)

  8. Thermodynamic framework for discrete optimal control in multiphase flow systems

    Science.gov (United States)

    Sieniutycz, Stanislaw

    1999-08-01

    Bellman's method of dynamic programming is used to synthesize diverse optimization approaches to active (work producing) and inactive (entropy generating) multiphase flow systems. Thermal machines, optimally controlled unit operations, nonlinear heat conduction, spontaneous relaxation processes, and self-propagating wave fronts are all shown to satisfy a discrete Hamilton-Jacobi-Bellman equation and a corresponding discrete optimization algorithm of Pontryagin's type, with the maximum principle for a Hamiltonian. The extremal structures are always canonical. A common unifying criterion is set for all considered systems, which is the criterion of a minimum generated entropy. It is shown that constraints can modify the entropy functionals in a different way for each group of the processes considered; thus the resulting structures of these functionals may differ significantly. Practical conclusions are formulated regarding the energy savings and energy policy in optimally controlled systems.

  9. Bubble gate for in-plane flow control.

    Science.gov (United States)

    Oskooei, Ali; Abolhasani, Milad; Günther, Axel

    2013-07-07

    We introduce a miniature gate valve as a readily implementable strategy for actively controlling the flow of liquids on-chip, within a footprint of less than one square millimetre. Bubble gates provide for simple, consistent and scalable control of liquid flow in microchannel networks, are compatible with different bulk microfabrication processes and substrate materials, and require neither electrodes nor moving parts. A bubble gate consists of two microchannel sections: a liquid-filled channel and a gas channel that intercepts the liquid channel to form a T-junction. The open or closed state of a bubble gate is determined by selecting between two distinct gas pressure levels: the lower level corresponds to the "open" state while the higher level corresponds to the "closed" state. During closure, a gas bubble penetrates from the gas channel into the liquid, flanked by a column of equidistantly spaced micropillars on each side, until the flow of liquid is completely obstructed. We fabricated bubble gates using single-layer soft lithographic and bulk silicon micromachining procedures and evaluated their performance with a combination of theory and experimentation. We assessed the dynamic behaviour during more than 300 open-and-close cycles and report the operating pressure envelope for different bubble gate configurations and for the working fluids: de-ionized water, ethanol and a biological buffer. We obtained excellent agreement between the experimentally determined bubble gate operational envelope and a theoretical prediction based on static wetting behaviour. We report case studies that serve to illustrate the utility of bubble gates for liquid sampling in single and multi-layer microfluidic devices. Scalability of our strategy was demonstrated by simultaneously addressing 128 bubble gates.

  10. Flow control at low Reynolds numbers using periodic airfoil morphing

    Science.gov (United States)

    Jones, Gareth; Santer, Matthew; Papadakis, George; Bouremel, Yann; Debiasi, Marco; Imperial-NUS Joint PhD Collaboration

    2014-11-01

    The performance of airfoils operating at low Reynolds numbers is known to suffer from flow separation even at low angles of attack as a result of their boundary layers remaining laminar. The lack of mixing---a characteristic of turbulent boundary layers---leaves laminar boundary layers with insufficient energy to overcome the adverse pressure gradient that occurs in the pressure recovery region. This study looks at periodic surface morphing as an active flow control technique for airfoils in such a flight regime. It was discovered that at sufficiently high frequencies an oscillating surface is capable of not only reducing the size of the separated region---and consequently significantly reducing drag whilst simultaneously increasing lift---but it is also capable of delaying stall and as a result increasing CLmax. Furthermore, by bonding Macro Fiber Composite actuators (MFCs) to the underside of an airfoil skin and driving them with a sinusoidal frequency, it is shown that this control technique can be practically implemented in a lightweight, energy efficient way. Imperial-NUS Joint Ph.D. Programme.

  11. Dynamic flow control strategies of vehicle SCR Urea Dosing System

    Science.gov (United States)

    Lin, Wei; Zhang, Youtong; Asif, Malik

    2015-03-01

    Selective Catalyst Reduction(SCR) Urea Dosing System(UDS) directly affects the system accuracy and the dynamic response performance of a vehicle. However, the UDS dynamic response is hard to keep up with the changes of the engine's operating conditions. That will lead to low NO X conversion efficiency or NH3 slip. In order to optimize the injection accuracy and the response speed of the UDS in dynamic conditions, an advanced control strategy based on an air-assisted volumetric UDS is presented. It covers the methods of flow compensation and switching working conditions. The strategy is authenticated on an UDS and tested in different dynamic conditions. The result shows that the control strategy discussed results in higher dynamic accuracy and faster dynamic response speed of UDS. The inject deviation range is improved from being between -8% and 10% to -4% and 2% and became more stable than before, and the dynamic response time was shortened from 200 ms to 150 ms. The ETC cycle result shows that after using the new strategy the NH3 emission is reduced by 60%, and the NO X emission remains almost unchanged. The trade-off between NO X conversion efficiency and NH3 slip is mitigated. The studied flow compensation and switching working conditions can improve the dynamic performance of the UDS significantly and make the UDS dynamic response keep up with the changes of the engine's operating conditions quickly.

  12. Microcomputer-controlled flow meter used on a water loop

    International Nuclear Information System (INIS)

    Haniger, L.

    1982-01-01

    The report describes a microcomputer-controlled instrument intended for operational measurement on an experimental water loop. On the basis of pressure and temperature input signals the instrument calculates the specific weight, and for ten operator-selectable measuring channels it calculates the mass flow G(kp/s), or the voluminal flow Q(m 3 /h). On pressing the appropriate push-buttons the built-in display indicates the values of pressure (p) and temperature (t), as well as the values of specific weight γ calculated therefrom. For ten individually selectable channels the instrument displays either the values of the pressure differences of the measuring throttling elements (√Δpsub(i)), or the values of Gsub(i) or Qsub(i) as obtained by calculation. In addition, on pressing the Σ-push-button it summarizes the values of Gsub(i) and Qsub(i) for the selected channels. The device is controlled by an 8085 microprocessor, the analog unit MP 6812 being used as the A/D convertor. The instrument algorithm indicates some possible errors which may concern faults of input signals or mistakes in calculation. (author)

  13. Provably correct control flow graphs from Java bytecode programs with exceptions

    NARCIS (Netherlands)

    Amighi, A.; de Carvalho Gomes, Pedro; Gurov, Dilian; Huisman, Marieke

    2016-01-01

    We present an algorithm for extracting control flow graphs from Java bytecode that captures normal as well as exceptional control flow. We prove its correctness, in the sense that the behaviour of the extracted control flow graph is a sound over-approximation of the behaviour of the original

  14. A high turndown, ultra low emission low swirl burner for natural gas, on-demand water heaters

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cheng, Robert K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Therkelsen, Peter L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-06-13

    Previous research has shown that on-demand water heaters are, on average, approximately 37% more efficient than storage water heaters. However, approximately 98% of water heaters in the U.S. use storage water heaters while the remaining 2% are on-demand. A major market barrier to deployment of on-demand water heaters is their high retail cost, which is due in part to their reliance on multi-stage burner banks that require complex electronic controls. This project aims to research and develop a cost-effective, efficient, ultra-low emission burner for next generation natural gas on-demand water heaters in residential and commercial buildings. To meet these requirements, researchers at the Lawrence Berkeley National Laboratory (LBNL) are adapting and testing the low-swirl burner (LSB) technology for commercially available on-demand water heaters. In this report, a low-swirl burner is researched, developed, and evaluated to meet targeted on-demand water heater performance metrics. Performance metrics for a new LSB design are identified by characterizing performance of current on-demand water heaters using published literature and technical specifications, and through experimental evaluations that measure fuel consumption and emissions output over a range of operating conditions. Next, target metrics and design criteria for the LSB are used to create six 3D printed prototypes for preliminary investigations. Prototype designs that proved the most promising were fabricated out of metal and tested further to evaluate the LSB’s full performance potential. After conducting a full performance evaluation on two designs, we found that one LSB design is capable of meeting or exceeding almost all the target performance metrics for on-demand water heaters. Specifically, this LSB demonstrated flame stability when operating from 4.07 kBTU/hr up to 204 kBTU/hr (50:1 turndown), compliance with SCAQMD Rule 1146.2 (14 ng/J or 20 ppm NOX @ 3% O2), and lower CO emissions than state

  15. End-tidal control vs. manually controlled minimal-flow anesthesia: a prospective comparative trial.

    Science.gov (United States)

    Wetz, A J; Mueller, M M; Walliser, K; Foest, C; Wand, S; Brandes, I F; Waeschle, R M; Bauer, M

    2017-11-01

    To ensure safe general anesthesia, manually controlled anesthesia requires constant monitoring and numerous manual adjustments of the gas dosage, especially for low- and minimal-flow anesthesia. Oxygen flow-rate and administration of volatile anesthetics can also be controlled automatically by anesthesia machines using the end-tidal control technique, which ensures constant end-tidal concentrations of oxygen and anesthetic gas via feedback and continuous adjustment mechanisms. We investigated the hypothesis that end-tidal control is superior to manually controlled minimal-flow anesthesia (0.5 l/min). In this prospective trial, we included 64 patients undergoing elective surgery under general anesthesia. We analyzed the precision of maintenance of the sevoflurane concentration (1.2-1.4%) and expiratory oxygen (35-40%) and the number of necessary adjustments. Target-concentrations of sevoflurane and oxygen were maintained at more stable levels with the use of end-tidal control (during the first 15 min 28% vs. 51% and from 15 to 60 min 1% vs. 19% deviation from sevoflurane target, P tidal oxygen (5, IQR 3-6). The target-concentrations were reached earlier with the use of end-tidal compared with manual controlled minimal-flow anesthesia but required slightly greater use of anesthetic agents (6.9 vs. 6.0 ml/h). End-tidal control is a superior technique for setting and maintaining oxygen and anesthetic gas concentrations in a stable and rapid manner compared with manual control. Consequently, end-tidal control can effectively support the anesthetist. © 2017 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  16. Interim results: fines recycle testing using the 4-inch diameter primary graphite burner

    International Nuclear Information System (INIS)

    Palmer, W.B.

    1975-05-01

    The results of twenty-two HTGR primary burner runs in which graphite fines were recycled pneumatically to the 4-inch diameter pilot-plant primary fluidized-bed burner are described. The result of the tests showed that zero fines accumulation can easily be achieved while operating at plant equivalent burn rates. (U.S.)

  17. Synthesis of Titanium Dioxide Nanoparticles Using a Double-Slit Curved Wall-Jet Burner

    KAUST Repository

    Ismail, Mohamed; Mansour, Morkous S.; Memon, Nasir K.; Anjum, Dalaver H.; Chung, Suk-Ho

    2016-01-01

    A novel double-slit curved wall-jet (DS-CWJ) burner was proposed and utilized for flame synthesis. This burner was comprised of double curved wall-jet nozzles with coaxial slits; the inner slit was for the delivery of titanium tetraisopropoxide

  18. Oil fired boiler/solar tank- and natural gas burner/solar tank-units

    DEFF Research Database (Denmark)

    Furbo, Simon; Vejen, Niels Kristian; Frederiksen, Karsten Vinkler

    1999-01-01

    During the last few years new units consisting of a solar tank and either an oil fired boiler or a natural gas burner have been introduced on the Danish market. Three different marketed units - two based on a natural gas burner and one based on an oil fired boiler - have been tested in a heat...

  19. Minnowbrook VI: 2009 Workshop on Flow Physics and Control for Internal and External Aerodynamics

    Science.gov (United States)

    LaGraff, John E.; Povinelli, Louis A.; Gostelow, J. Paul; Glauser, Mark

    2010-01-01

    Topics covered include: Flow Physics and control for Internal and External Aerodynamics (not in TOC...starts on pg13); Breaking CFD Bottlenecks in Gas-Turbine Flow-Path Design; Streamwise Vortices on the Convex Surfaces of Circular Cylinders and Turbomachinery Blading; DNS and Embedded DNS as Tools for Investigating Unsteady Heat Transfer Phenomena in Turbines; Cavitation, Flow Structure and Turbulence in the Tip Region of a Rotor Blade; Development and Application of Plasma Actuators for Active Control of High-Speed and High Reynolds Number Flows; Active Flow Control of Lifting Surface With Flap-Current Activities and Future Directions; Closed-Loop Control of Vortex Formation in Separated Flows; Global Instability on Laminar Separation Bubbles-Revisited; Very Large-Scale Motions in Smooth and Rough Wall Boundary Layers; Instability of a Supersonic Boundary-Layer With Localized Roughness; Active Control of Open Cavities; Amplitude Scaling of Active Separation Control; U.S. Air Force Research Laboratory's Need for Flow Physics and Control With Applications Involving Aero-Optics and Weapon Bay Cavities; Some Issues Related to Integrating Active Flow Control With Flight Control; Active Flow Control Strategies Using Surface Pressure Measurements; Reduction of Unsteady Forcing in a Vaned, Contra-Rotating Transonic Turbine Configuration; Active Flow Control Stator With Coanda Surface; Controlling Separation in Turbomachines; Flow Control on Low-Pressure Turbine Airfoils Using Vortex Generator Jets; Reduced Order Modeling Incompressible Flows; Study and Control of Flow Past Disk, and Circular and Rectangular Cylinders Aligned in the Flow; Periodic Forcing of a Turbulent Axisymmetric Wake; Control of Vortex Breakdown in Critical Swirl Regime Using Azimuthal Forcing; External and Turbomachinery Flow Control Working Group; Boundary Layers, Transitions and Separation; Efficiency Considerations in Low Pressure Turbines; Summary of Conference; and Final Plenary Session

  20. Mach 0.3 Burner Rig Facility at the NASA Glenn Materials Research Laboratory

    Science.gov (United States)

    Fox, Dennis S.; Miller, Robert A.; Zhu, Dongming; Perez, Michael; Cuy, Michael D.; Robinson, R. Craig

    2011-01-01

    This Technical Memorandum presents the current capabilities of the state-of-the-art Mach 0.3 Burner Rig Facility. It is used for materials research including oxidation, corrosion, erosion and impact. Consisting of seven computer controlled jet-fueled combustors in individual test cells, these relatively small rigs burn just 2 to 3 gal of jet fuel per hour. The rigs are used as an efficient means of subjecting potential aircraft engine/airframe advanced materials to the high temperatures, high velocities and thermal cycling closely approximating actual operating environments. Materials of various geometries and compositions can be evaluated at temperatures from 700 to 2400 F. Tests are conducted not only on bare superalloys and ceramics, but also to study the behavior and durability of protective coatings applied to those materials.

  1. Experiential study on temperature and emission performance of micro burner during porous media combustion

    Science.gov (United States)

    Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, A.; Ismail, A. K.; Hussien, A. A.; Kataraki, P. S.; Ishak, M. H. H.; Mazlan, M.; Zubair, A. F.

    2018-05-01

    Addition of porous materials in reaction zone give rise to significant improvements in combustion performance. In this work, a dual layered micro porous media burner was tested for stable flame and emissions. Reaction and preheat layer was made up of discrete (zirconia) and foam (porcelain) type of materials respectively. Three different thickness of reaction zone was tested, each with 10, 20 and 30mm. Interestingly, only 20mm thick layer can able to show better thermal efficiency of 72% as compared to 10 and 30mm. Best equivalence ratio came out to be 0.7 for surface and 0.6 for submerged flame conditions. Moreover, emission was continuously monitored to detect presence of NOx and CO, which were under controlled limits.

  2. Power flow analysis for islanded microgrid in hierarchical structure of control system using optimal control theory

    Directory of Open Access Journals (Sweden)

    Thang Diep Thanh

    2017-12-01

    Full Text Available In environmental uncertainties, the power flow problem in islanded microgrid (MG becomes complex and non-trivial. The optimal power flow (OPL problem is described in this paper by using the energy balance between the power generation and load demand. The paper also presents the hierarchical control structure which consists of primary, secondary, tertiary, and emergency controls. Clearly, optimal power flow (OPL which implements a distributed tertiary control in hierarchical control. MG consists of diesel engine generator (DEG, wind turbine generator (WTG, and photovoltaic (PV power. In the control system considered, operation planning is realized based on profiles such that the MG, load, wind and photovoltaic power must be forecasted in short-period, meanwhile the dispatch source (i.e., DEG needs to be scheduled. The aim of the control problem is to find the dispatch output power by minimizing the total cost of energy that leads to the Hamilton-Jacobi-Bellman equation. Experimental results are presented, showing the effectiveness of optimal control such that the generation allows demand profile.

  3. Backbone of complex networks of corporations: The flow of control

    Science.gov (United States)

    Glattfelder, J. B.; Battiston, S.

    2009-09-01

    We present a methodology to extract the backbone of complex networks based on the weight and direction of links, as well as on nontopological properties of nodes. We show how the methodology can be applied in general to networks in which mass or energy is flowing along the links. In particular, the procedure enables us to address important questions in economics, namely, how control and wealth are structured and concentrated across national markets. We report on the first cross-country investigation of ownership networks, focusing on the stock markets of 48 countries around the world. On the one hand, our analysis confirms results expected on the basis of the literature on corporate control, namely, that in Anglo-Saxon countries control tends to be dispersed among numerous shareholders. On the other hand, it also reveals that in the same countries, control is found to be highly concentrated at the global level, namely, lying in the hands of very few important shareholders. Interestingly, the exact opposite is observed for European countries. These results have previously not been reported as they are not observable without the kind of network analysis developed here.

  4. Development of the Radiation Stabilized Distributed Flux Burner - Phase III Final Report

    Energy Technology Data Exchange (ETDEWEB)

    J. D. Sullivan; A. Webb

    1999-12-01

    The development and demonstration of the Radiation Stabilized Burner (RSB) was completed as a project funded by the US Department of Energy Office of Industrial Technologies. The technical goals of the project were to demonstrate burner performance that would meet or exceed emissions targets of 9 ppm NOx, 50 ppm CO, and 9 ppm unburned hydrocarbons (UHC), with all values being corrected to 3 percent stack oxygen, and incorporate the burner design into a new industrial boiler configuration that would achieve ultra-low emissions while maintaining or improving thermal efficiency, operating costs, and maintenance costs relative to current generation 30 ppm low NOx burner installations. Both the ultra-low NOx RSB and the RSB boiler-burner package are now commercially available.

  5. Numerical investigation of a novel burner to combust anode exhaust gases of SOFC stacks

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-09-01

    Full Text Available The aim of the present study was a numerical investigation of the efficiency of the combustion process of a novel concept burner under different operating conditions. The design of the burner was a part of the development process of a complete SOFC based system and a challenging combination of technical requirements to be fulfilled. A Computational Fluid Dynamics model of a non-premixed burner was used to simulate combustion of exhaust gases from the anode region of Solid Oxide Fuel Cell stacks. The species concentrations of the exhaust gases were compared with experimental data and a satisfactory agreement of the conversion of hydrocarbons was obtained. This validates the numerical methodology and also proves applicability of the developed approach that quantitatively characterized the interaction between the exhaust gases and burner geometry for proper combustion modelling. Thus, the proposed CFD approach can be safely used for further numerical optimisation of the burner design.

  6. Dielectric barrier discharge plasma actuator for flow control

    Science.gov (United States)

    Opaits, Dmitry Florievich

    Electrohydrodynamic (EHD) and magnetohydrodynamic phenomena are being widely studied for aerodynamic applications. The major effects of these phenomena are heating of the gas, body force generation, and enthalpy addition or extraction, [1, 2, 3]. In particular, asymmetric dielectric barrier discharge (DBD) plasma actuators are known to be effective EHD device in aerodynamic control, [4, 5]. Experiments have demonstrated their effectiveness in separation control, acoustic noise reduction, and other aeronautic applications. In contrast to conventional DBD actuators driven by sinusoidal voltages, we proposed and used a voltage profile consisting of nanosecond pulses superimposed on dc bias voltage. This produces what is essentially a non-self-sustained discharge: the plasma is generated by repetitive short pulses, and the pushing of the gas occurs primarily due to the bias voltage. The advantage of this non-self-sustained discharge is that the parameters of ionizing pulses and the driving bias voltage can be varied independently, which adds flexibility to control and optimization of the actuators performance. Experimental studies were conducted of a flow induced in a quiescent room air by a single DBD actuator. A new approach for non-intrusive diagnostics of plasma actuator induced flows in quiescent gas was proposed, consisting of three elements coupled together: the Schlieren technique, burst mode of plasma actuator operation, and 2-D numerical fluid modeling. During the experiments, it was found that DBD performance is severely limited by surface charge accumulation on the dielectric. Several ways to mitigate the surface charge were found: using a reversing DC bias potential, three-electrode configuration, slightly conductive dielectrics, and semi conductive coatings. Force balance measurements proved the effectiveness of the suggested configurations and advantages of the new voltage profile (pulses+bias) over the traditional sinusoidal one at relatively low

  7. Design and construction of a regenerative radiant tube burner

    International Nuclear Information System (INIS)

    Henao, Diego Alberto; Cano C, Carlos Andres; Amell Arrieta, Andres A.

    2002-01-01

    The technological development of the gas industry in Colombia, aiming at efficient and safe use of the natural gas, requires the assimilation and adaptation of new generation, technologies for this purpose in this article results are presented on the design, construction and characterization of a prototype of a burner of regenerative radiant robe with a thermal power of 9,94 kW and a factor of air 1,05. This system takes advantage of the high exit temperature of the combustion smokes, after they go trough a metallic robe where they transfer the heat by radiation, to heat a ceramic channel that has the capacity to absorbing a part of the heat of the smokes and then transferring them to a current of cold air. The benefits of air heating are a saving in fuel, compared with other processes that don't incorporate the recovery of heat from the combustion gases. In this work it was possible to probe a methodology for the design of this type of burners and to reach maximum temperatures of heating of combustion air of 377,9 centigrade degrees, using a material available in the national market, whose regenerative properties should be studied in depth

  8. 40 CFR 63.6092 - Are duct burners and waste heat recovery units covered by subpart YYYY?

    Science.gov (United States)

    2010-07-01

    ... Combustion Turbines What This Subpart Covers § 63.6092 Are duct burners and waste heat recovery units covered by subpart YYYY? No, duct burners and waste heat recovery units are considered steam generating units... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Are duct burners and waste heat...

  9. Flow Diode and Method for Controlling Fluid Flow Origin of the Invention

    Science.gov (United States)

    Dyson, Rodger W (Inventor)

    2015-01-01

    A flow diode configured to permit fluid flow in a first direction while preventing fluid flow in a second direction opposite the first direction is disclosed. The flow diode prevents fluid flow without use of mechanical closures or moving parts. The flow diode utilizes a bypass flowline whereby all fluid flow in the second direction moves into the bypass flowline having a plurality of tortuous portions providing high fluidic resistance. The portions decrease in diameter such that debris in the fluid is trapped. As fluid only travels in one direction through the portions, the debris remains trapped in the portions.

  10. The influence of the furnace design on emissions from small wood pellet burners

    International Nuclear Information System (INIS)

    Aspfors, Jonas; Larfeldt, Jenny

    1999-01-01

    Two pellet burners have been installed and tested in a small scale boiler for house heating. The boiler is representative for the Swedish households and the burners, upwards and forward burning, are commercially available on the Swedish market. This work focuses on the boiler operation and particularly the potential of improved emissions by changing the furnace design. An insulation of the fireplace lowered the emission of CO by 50% and the emission of OGC by 60% for the upwards burning burner at low load. Modifying the furnace using baffles did not have any influence on the emissions. It is concluded that an increased temperature in the furnace is more important than an increased residence time of the combustible gases to decrease the emissions. At full load both burners emit approximately 300 mg CO per nm 3 gas and the emission of OGC are negligible. At half load the emissions of CO increased to 1000 mg/m n 3 and OGC to 125 mg/m n 3 in the upward burning burner. The forwards burning burner had a small increase in OGC to about 10 mg/m n 3 at half load while the emission of CO increased to 800 mg/m n 3 . The forward burning burner is less influenced on the furnace design compared to the upward burning burner. The comparatively high emissions of OGC for the upward burning burner is explained by the intermittent operation. However, it was possible to reduce the emissions from this burner by ceramic insulation of the furnace Project report from the program: Small scale combustion of biofuels. 3 refs, 12 figs, 2 tab, 1 appendix with 33 figs and 12 tabs

  11. Modelling and exergoeconomic-environmental analysis of combined cycle power generation system using flameless burner for steam generation

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Barzegaravval, Hasan; Ganjehkaviri, Abdolsaeid; Wahid, Mazlan Abdul; Mohd Jaafar, M.N.

    2017-01-01

    Highlights: • Using flameless burner as a supplementary firing system after gas turbine is modeled. • Thermodynamic, economic and environmental analyses of this model are performed. • Efficiency of the plant increases about 6% and CO_2 emission decreases up to 5.63% in this design. • Available exergy for work production in both gas cycle and steam cycle increases in this model. - Abstract: To have an optimum condition for the performance of a combined cycle power generation, using supplementary firing system after gas turbine was investigated by various researchers. Since the temperature of turbine exhaust is higher than auto-ignition temperature of the fuel in optimum condition, using flameless burner is modelled in this paper. Flameless burner is installed between gas turbine cycle and Rankine cycle of a combined cycle power plant which one end is connected to the outlet of gas turbine (as primary combustion oxidizer) and the other end opened to the heat recovery steam generator. Then, the exergoeconomic-environmental analysis of the proposed model is evaluated. Results demonstrate that efficiency of the combined cycle power plant increases about 6% and CO_2 emission reduces up to 5.63% in this proposed model. It is found that the variation in the cost is less than 1% due to the fact that a cost constraint is implemented to be equal or lower than the design point cost. Moreover, exergy of flow gases increases in all points except in heat recovery steam generator. Hence, available exergy for work production in both gas cycle and steam cycle will increase in new model.

  12. A NEW DOUBLE-SLIT CURVED WALL-JET (CWJ) BURNER FOR STABILIZING TURBULENT PREMIXED AND NON-PREMIXED FLAMES

    KAUST Repository

    Mansour, Morkous S.

    2015-06-30

    A novel double-slit curved wall-jet (CWJ) burner was proposed and employed, which utilizes the Coanda effect by supplying fuel and air as annular-inward jets over a curved surface. We investigated the stabilization characteristics and structure of methane/air, and propane/air turbulent premixed and non-premixed flames with varying global equivalence ratio, , and Reynolds number, Re. Simultaneous time-resolved measurements of particle image velocimetry and planar laser-induced fluorescence of OH radicals were conducted. The burner showed potential for stable operation for methane flames with relatively large fuel loading and overall rich conditions. These have a non-sooting nature. However, propane flames exhibit stable mode for a wider range of equivalence ratio and Re. Mixing characteristics in the cold flow of non-premixed cases were first examined using acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions.PIV measurements revealed that velocity gradients in the shear layers at the boundaries of the annularjets generate the turbulence, enhanced with the collisions in the interaction jet, IJ,region. Turbulent mean and rms velocities were influenced significantly by Re and high rms turbulent velocities are generated within the recirculation zone improving the flame stabilization in this burner.Premixed and non-premixed flames with high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Re. For flames with low equivalence ratio, the processes of local quenching at IJ region and of re-ignition within merged jet region maintained these flames further downstream particularly for non-premixed methane flame, revealing a strong intermittency.

  13. Dynamic evolution process of turbulent channel flow after opposition control

    Energy Technology Data Exchange (ETDEWEB)

    Ge, Mingwei; Tian, De; Yongqian, Liu, E-mail: gmwncepu@163.com [State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources (North China Electric Power University), Beijing102206 (China)

    2017-02-15

    Dynamic evolution of turbulent channel flow after application of opposition control (OC), together with the mechanism of drag reduction, is studied through direct numerical simulation (DNS). In the simulation, the pressure gradient is kept constant, and the flow rate increases due to drag reduction. In the transport of mean kinetic energy (MKE), one part of the energy from the external pressure is dissipated by the mean shear, and the other part is transported to the turbulent kinetic energy (TKE) through a TKE production term (TKP). It is found that the increase of MKE is mainly induced by the reduction of TKP that is directly affected by OC. Further analysis shows that the suppression of the redistribution term of TKE in the wall normal direction plays a key role in drag reduction, which represses the wall normal velocity fluctuation and then reduces TKP through the attenuation of its main production term. When OC is suddenly applied, an acute imbalance of energy in space is induced by the wall blowing and suction. Both the skin-friction and TKP terms exhibit a transient growth in the initial phase of OC, which can be attributed to the local effect of 〈 v ′ v ′〉 and 〈− u ′ v ′〉 in the viscous sublayer. (paper)

  14. Modelling of flow stabilization by the swirl of a peripheral flow as applied to plasma reactors

    International Nuclear Information System (INIS)

    Volchkov, E.P.; Lebedev, V.P.; Terekhov, V.I.; Shishkin, N.E.

    2000-01-01

    The gas-swirl stabilization of plasma jets is one of effective methods of its retention in the near-axial area of channels in generators of low-temperature plasma. Except the effect of gas-dynamic compression, the peripheral swirl allows to solve another urgent problem - to protect the reactor walls from the heat influence of the plasma jet. Swirl flows are also used for the flow structure formation and control of the heat and gas-dynamic characteristics of different power devices and apparatuses, using high-temperature working media: in swirl furnaces and burners, in aviation engines, etc. Investigations show that during swirl stabilization the gas-dynamic structure of the flow influences significantly the spatial stability of the plasma column and its characteristics

  15. Parallel Vortex Body Interaction Enabled by Active Flow Control

    Science.gov (United States)

    Weingaertner, Andre; Tewes, Philipp; Little, Jesse

    2017-11-01

    An experimental study was conducted to explore the flow physics of parallel vortex body interaction between two NACA 0012 airfoils. Experiments were carried out at chord Reynolds numbers of 740,000. Initially, the leading airfoil was characterized without the target one being installed. Results are in good agreement with thin airfoil theory and data provided in the literature. Afterward, the leading airfoil was fixed at 18° incidence and the target airfoil was installed 6 chord lengths downstream. Plasma actuation (ns-DBD), originating close to the leading edge, was used to control vortex shedding from the leading airfoil at various frequencies (0.04 governing parameters of this vortex body interaction are explored. This work was supported by the Army Research Office under ARO Grant No. W911NF-14-1-0662.

  16. Chaos control for the plates subjected to subsonic flow

    Science.gov (United States)

    Norouzi, Hamed; Younesian, Davood

    2016-07-01

    The suppression of chaotic motion in viscoelastic plates driven by external subsonic air flow is studied. Nonlinear oscillation of the plate is modeled by the von-Kármán plate theory. The fluid-solid interaction is taken into account. Galerkin's approach is employed to transform the partial differential equations of the system into the time domain. The corresponding homoclinic orbits of the unperturbed Hamiltonian system are obtained. In order to study the chaotic behavior of the plate, Melnikov's integral is analytically applied and the threshold of the excitation amplitude and frequency for the occurrence of chaos is presented. It is found that adding a parametric perturbation to the system in terms of an excitation with the same frequency of the external force can lead to eliminate chaos. Variations of the Lyapunov exponent and bifurcation diagrams are provided to analyze the chaotic and periodic responses. Two perturbation-based control strategies are proposed. In the first scenario, the amplitude of control forces reads a constant value that should be precisely determined. In the second strategy, this amplitude can be proportional to the deflection of the plate. The performance of each controller is investigated and it is found that the second scenario would be more efficient.

  17. Unsteady Flows Control Hydrologic Turnover Rates in Antarctic Hyporheic Zones

    Science.gov (United States)

    Wlostowski, A. N.; Gooseff, M. N.; McKnight, D. M.; Lyons, W. B.; Saelens, E.

    2016-12-01

    Hydrologic turnover of the hyporheic zone (HZ) is the process of HZ flowpaths receiving water and solutes from the stream channel while simultaneously contributing water and solutes from the HZ back to the stream channel. The influence of hydrologic turnover on HZ solute storage depends on the relative magnitude of hyporheic exchange rates (i.e. physical transport) and biogeochemical reaction rates. Because both exchange rates and reaction rates are unsteady in natural systems, the availability of solutes in the HZ is controlled by the legacy of hydraulic and biological conditions. In this study, we quantify the influence of unsteady flows on hydrologic turnover of the HZ. We study a glacial melt stream in the McMurdo Dry Valleys of Antarctica (MDVs). The MDVs provide an ideal setting for investigating hydrologic and chemical storage characteristics of HZs, because nearly all streamflow is generated from glacier melt and the HZ is vertically bounded by continuous permafrost. A dense network of shallow groundwater wells and piezometers was installed along a 60-meter reach of Von Guerard Stream. 12 days of continuous water level data in each well was used to compute the magnitude and direction of 2D hydraulic gradients between the stream channel and lateral hyporheic aquifer. Piezometers were sampled daily for stable isotope abundances. The direction and magnitude of the cross-valley (CV), perpendicular to the thalweg, component of hydraulic gradients is sensitive to daily flood events and exhibits significant spatial heterogeneity. CV gradients are consistently oriented from the hyporheic aquifer towards the stream channel on 2 sections of the study reach, whereas CV gradients are consistently oriented from the stream channel towards the hyporheic aquifer on 1 section. Three sections show diel changes in orientation of CV gradients, coincident with the passage of daily flood events. During a 4-day period of low flows, the HZ is isotopically distinct from the stream

  18. The friction control of magnetic fluid in the Couette flow

    Energy Technology Data Exchange (ETDEWEB)

    Labkovich, O.N., E-mail: olji@tut.by; Reks, A.G.; Chernobai, V.A.

    2017-06-01

    In the work characteristic areas of magnetic fluid flow are experimentally determined in the gap between the cylinders: the area of strong dipole-dipole interaction between magnetite particles 0flow 8flow Ta>41,2. For areas with high flow losses in viscous friction is shown the possibility of reducing the introduction of magnetic fluid of carbon nanotubes and creating a rotating magnetic field. - Highlights: • Typical areas of magnetic fluid flow are determined in the gap. • Influence of dipole-dipole interaction of magnetite particles on the viscous friction. • Features of Taylor vortex flow.

  19. Provably Correct Control-Flow Graphs from Java Programs with Exceptions

    NARCIS (Netherlands)

    Amighi, A.; de Carvalho Gomes, Pedro; Huisman, Marieke

    2011-01-01

    We present an algorithm to extract flow graphs from Java bytecode, focusing on exceptional control flows. We prove its correctness, meaning that the behaviour of the extracted control-flow graph is an over-approximation of the behaviour of the original program. Thus any safety property that holds

  20. Spray characteristics and liquid distribution of multi-hole effervescent atomisers for industrial burners

    International Nuclear Information System (INIS)

    Jedelský, Jan; Jícha, Miroslav

    2016-01-01

    Highlights: • The multi-hole (mh) spray morphology is very similar to that of single-hole nozzles. • Unsteady spray was found at low pressure and low gas-to-liquid-ratio (GLR) values. • Cone angle variation in mh spray with pressure and GLR depends on the exit nozzles angle. • A liquid–gas gravitational separation in horizontal atomiser operation was observed. • It causes up to 70% fuel supply variance into exit holes depending on design and regime. - Graphical Abstract: - Abstract: The present paper provides an experimental study and optimisation of multi-hole effervescent atomisers for industrial burners using oil-based fossil, bio- or waste fuels with prospects of emission reduction. Several multi-hole nozzles were designed based on our previous work. We probed the spray quality by phase-Doppler anemometry. 3-D plots of Sauter mean diameter and mean droplet velocity demonstrate their spatial distribution within the spray. The effect of geometrical and operational factors on the spray is discussed. Droplet size–velocity correlations as well as the size and velocity distributions are presented, and differences are found against other investigations. A spray macrostructure is photographically observed and spray cone angles of the multi-hole nozzles are analysed. An internal two-phase flow is estimated using the Baker's map for horizontal two-phase flow. Our previous two-phase flow visualisations suggested a liquid–gas gravitational separation when the multi-hole atomiser operated horizontally. This issue is addressed here; the results of spray heterogeneity measurements document that fuel flow rates through individual exit holes differ significantly. This difference spans between 0 and 70% depending on the nozzle design and flow regime. Effervescent sprays are unsteady under some operating conditions; spray unsteadiness was detected at low pressure and low gas-to-liquid-ratios.

  1. Blow-off characteristics of turbulent premixed flames in curved-wall Jet Burner

    KAUST Repository

    Mansour, Morkous S.

    2015-08-02

    This study concerns the flame dynamics of a curved-wall jet (CWJ) stabilized turbulent premixed flame as it approaches blow-off conditions. Time resolved OH planar laser-induced fluorescence (PLIF) delineated reaction zone contours and simultaneously stereoscopic particle image velocimetry (SPIV) quantified the turbulent flow field features. Ethylene/air flames were stabilized in CWJ burner to determine the sequence of events leading to blowoff. For stably burning flames far from blowoff, flames are characterized with a recirculation zone (RZ) upstream for flame stabilization followed by an intense turbulent interaction jet (IJ) and merged-jet regions downstream; the flame front counterparts the shear layer vortices. Near blowoff, as the velocity of reactants increases, high local stretch rates exceed the extinction stretch rates instantaneously resulting in localized flame extinction along the IJ region. As Reynolds number (Re) increases, flames become shorter and are entrained by larger amounts of cold reactants. The increased strain rates together with heat loss effects result in further fragmentation of the flame, eventually leading to the complete quenching of the flame. This is explained in terms of local turbulent Karlovitz stretch factor (K) and principal flow strain rates associated with C contours. Hydrogen addition and increasing the RZ size lessen the tendency of flames to be locally extinguished.

  2. A small porous-plug burner for studies of combustion chemistry and soot formation

    Science.gov (United States)

    Campbell, M. F.; Schrader, P. E.; Catalano, A. L.; Johansson, K. O.; Bohlin, G. A.; Richards-Henderson, N. K.; Kliewer, C. J.; Michelsen, H. A.

    2017-12-01

    We have developed and built a small porous-plug burner based on the original McKenna burner design. The new burner generates a laminar premixed flat flame for use in studies of combustion chemistry and soot formation. The size is particularly relevant for space-constrained, synchrotron-based X-ray diagnostics. In this paper, we present details of the design, construction, operation, and supporting infrastructure for this burner, including engineering attributes that enable its small size. We also present data for charactering the flames produced by this burner. These data include temperature profiles for three premixed sooting ethylene/air flames (equivalence ratios of 1.5, 1.8, and 2.1); temperatures were recorded using direct one-dimensional coherent Raman imaging. We include calculated temperature profiles, and, for one of these ethylene/air flames, we show the carbon and hydrogen content of heavy hydrocarbon species measured using an aerosol mass spectrometer coupled with vacuum ultraviolet photoionization (VUV-AMS) and soot-volume-fraction measurements obtained using laser-induced incandescence. In addition, we provide calculated mole-fraction profiles of selected gas-phase species and characteristic profiles for seven mass peaks from AMS measurements. Using these experimental and calculated results, we discuss the differences between standard McKenna burners and the new miniature porous-plug burner introduced here.

  3. Experimental Studies of Low-Pressure Turbine Flows and Flow Control. Streamwise Pressure Profiles and Velocity Profiles

    Science.gov (United States)

    Volino, Ralph

    2012-01-01

    This report summarizes research performed in support of the NASA Glenn Research Center (GRC) Low-Pressure Turbine (LPT) Flow Physics Program. The work was performed experimentally at the U.S. Naval Academy faculties. The geometry corresponded to "Pak B" LPT airfoil. The test section simulated LPT flow in a passage. Three experimental studies were performed: (a) Boundary layer measurements for ten baseline cases under high and low freestream turbulence conditions at five Reynolds numbers of 25,000, 50,000, 100,000, 200,000, and 300,000, based on passage exit velocity and suction surface wetted length; (b) Passive flow control studies with three thicknesses of two-dimensional bars, and two heights of three-dimensional circular cylinders with different spanwise separations, at same flow conditions as the 10 baseline cases; (c) Active flow control with oscillating synthetic (zero net mass flow) vortex generator jets, for one case with low freestream turbulence and a low Reynolds number of 25,000. The Passive flow control was successful at controlling the separation problem at low Reynolds numbers, with varying degrees of success from case to case and varying levels of impact at higher Reynolds numbers. The active flow control successfully eliminated the large separation problem for the low Reynolds number case. Very detailed data was acquired using hot-wire anemometry, including single and two velocity components, integral boundary layer quantities, turbulence statistics and spectra, turbulent shear stresses and their spectra, and intermittency, documenting transition, separation and reattachment. Models were constructed to correlate the results. The report includes a summary of the work performed and reprints of the publications describing the various studies.This report summarizes research performed in support of the NASA Glenn Research Center (GRC) Low-Pressure Turbine (LPT) Flow Physics Program. The work was performed experimentally at the U.S. Naval Academy

  4. Environmental Assessment for the Commercial Demonstration of the Low NOx Burner/Separated Over-Fire Air (LNB/SOFA) Integration System Emission Reduction Technology, Finney County, Kansas

    Energy Technology Data Exchange (ETDEWEB)

    n/a

    2003-03-11

    The U.S. Department of Energy (DOE) proposes to provide partial funding to the Sunflower Electric Power Corporation (Sunflower), to demonstrate the commercial application of Low-NO{sub x} Burner/Separated Over-Fire Air (LNB/SOFA) integration system to achieve NO{sub x} emission reduction to the level of 0.15 to 0.22 pounds per million British thermal units (lb/MM Btu). The proposed project station is Sunflower's 360 MW coal-fired generation station, Holcomb Unit No. 1 (Holcomb Station). The station, fueled by coal from Wyoming's Powder River Basin, is located near Garden City, in Finney County, Kansas. The period of performance is expected to last approximately 2 years. The Holcomb Station, Sunflower LNB/SOFA integrated system would be modified in three distinct phases to demonstrate the synergistic effect of layering NO{sub x} control technologies. Once modified, the station would demonstrate that a unit equipped with an existing low-NO{sub x} burner system can be retrofitted with a new separated over-fire air (SOFA) system, coal flow measurement and control, and enhanced combustion monitoring to achieve about 45 percent reduction in nitrogen oxides (NO{sub x}) emissions. The proposed project would demonstrate a technology alternative to Selective Catalytic Reduction (SCR) systems. While SCR does generally achieve high reductions in NO{sub x} emissions (from about 0.8 lb/MM to 0.12 lb/MM Btu), it does so at higher capital and operating cost, requires the extensive use of critical construction labor, requires longer periods of unit outage for deployment, and generally requires longer periods of time to complete shakedown and full-scale operation. Cost of the proposed project technology would be on the order of 15-25 percent of that for SCR, with consequential benefits derived from reductions in construction manpower requirements and periods of power outages. This proposed technology demonstration would generally be applicable to boilers using opposed

  5. Numerical modelling of the CHEMREC black liquor gasification process. Conceptual design study of the burner in a pilot gasification reactor

    Energy Technology Data Exchange (ETDEWEB)

    Marklund, Magnus

    2001-02-01

    The work presented in this report is done in order to develop a simplified CFD model for Chemrec's pressurised black liquor gasification process. This process is presently under development and will have a number of advantages compared to conventional processes for black liquor recovery. The main goal with this work has been to get qualitative information on influence of burner design for the gas flow in the gasification reactor. Gasification of black liquor is a very complex process. The liquor is composed of a number of different substances and the composition may vary considerably between liquors originating from different mills and even for black liquor from a single process. When a black liquor droplet is gasified it loses its organic material to produce combustible gases by three stages of conversion: Drying, pyrolysis and char gasification. In the end of the conversion only an inorganic smelt remains (ideally). The aim is to get this smelt to form a protective layer, against corrosion and heat, on the reactor walls. Due to the complexity of gasification of black liquor some simplifications had to be made in order to develop a CFD model for the preliminary design of the gasification reactor. Instead of modelling droplets in detail, generating gas by gasification, sources were placed in a prescribed volume where gasification (mainly drying and pyrolysis) of the black liquor droplets was assumed to occur. Source terms for the energy and momentum equations, consistent with the mass source distribution, were derived from the corresponding control volume equations by assuming a symmetric outflow of gas from the droplets and a uniform degree of conversion of reactive components in the droplets. A particle transport model was also used in order to study trajectories from droplets entering the reactor. The resulting model has been implemented in a commercial finite volume code (AEA-CFX) through customised Fortran subroutines. The advantages with this simple

  6. Deposition stress effects on thermal barrier coating burner rig life

    Science.gov (United States)

    Watson, J. W.; Levine, S. R.

    1984-01-01

    A study of the effect of plasma spray processing parameters on the life of a two layer thermal barrier coating was conducted. The ceramic layer was plasma sprayed at plasma arc currents of 900 and 600 amps onto uncooled tubes, cooled tubes, and solid bars of Waspalloy in a lathe with 1 or 8 passes of the plasma gun. These processing changes affected the residual stress state of the coating. When the specimens were tested in a Mach 0.3 cyclic burner rig at 1130 deg C, a wide range of coating lives resulted. Processing factors which reduced the residual stress state in the coating, such as reduced plasma temperature and increased heat dissipation, significantly increased coating life.

  7. Combustion of solid alternative fuels in the cement kiln burner

    DEFF Research Database (Denmark)

    Nørskov, Linda Kaare

    In the cement industry there is an increasing environmental and financial motivation for substituting conventional fossil fuels with alternative fuels, being biomass or waste derived fuels. However, the introduction of alternative fuels may influence emissions, cement product quality, process...... stability, and process efficiency. Alternative fuel substitution in the calciner unit has reached close to 100% at many cement plants and to further increase the use of alternative fuels rotary kiln substitution must be enhanced. At present, limited systematic knowledge of the alternative fuel combustion...... properties and the influence on the flame formation is available. In this project a scientific approach to increase the fundamental understanding of alternative fuel conversion in the rotary kiln burner is employed through literature studies, experimental combustion characterisation studies, combustion...

  8. Burner rig alkali salt corrosion of several high temperature alloys

    Science.gov (United States)

    Deadmore, D. L.; Lowell, C. E.

    1977-01-01

    The hot corrosion of five alloys was studied in cyclic tests in a Mach 0.3 burner rig into whose combustion chamber various aqueous salt solutions were injected. Three nickel-based alloys, a cobalt-base alloy, and an iron-base alloy were studied at temperatures of 700, 800, 900, and 1000 C with various salt concentrations and compositions. The relative resistance of the alloys to hot corrosion attack was found to vary with temperature and both concentration and composition of the injected salt solution. Results indicate that the corrosion of these alloys is a function of both the presence of salt condensed as a liquid on the surface and of the composition of the gas phases present.

  9. A Modeling Tool for Household Biogas Burner Flame Port Design

    Science.gov (United States)

    Decker, Thomas J.

    Anaerobic digestion is a well-known and potentially beneficial process for rural communities in emerging markets, providing the opportunity to generate usable gaseous fuel from agricultural waste. With recent developments in low-cost digestion technology, communities across the world are gaining affordable access to the benefits of anaerobic digestion derived biogas. For example, biogas can displace conventional cooking fuels such as biomass (wood, charcoal, dung) and Liquefied Petroleum Gas (LPG), effectively reducing harmful emissions and fuel cost respectively. To support the ongoing scaling effort of biogas in rural communities, this study has developed and tested a design tool aimed at optimizing flame port geometry for household biogas-fired burners. The tool consists of a multi-component simulation that incorporates three-dimensional CAD designs with simulated chemical kinetics and computational fluid dynamics. An array of circular and rectangular port designs was developed for a widely available biogas stove (called the Lotus) as part of this study. These port designs were created through guidance from previous studies found in the literature. The three highest performing designs identified by the tool were manufactured and tested experimentally to validate tool output and to compare against the original port geometry. The experimental results aligned with the tool's prediction for the three chosen designs. Each design demonstrated improved thermal efficiency relative to the original, with one configuration of circular ports exhibiting superior performance. The results of the study indicated that designing for a targeted range of port hydraulic diameter, velocity and mixture density in the tool is a relevant way to improve the thermal efficiency of a biogas burner. Conversely, the emissions predictions made by the tool were found to be unreliable and incongruent with laboratory experiments.

  10. A burner for the combustion of spent tall oil soap

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, P.M.; Wong, J.K.; Moffatt, B.; Belanger, G. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre; Soriano, D. [Brais Malouin and Associates, Montreal, PQ (Canada)

    2003-07-01

    Efficiency in industrial processes applies both to the form of energy involved and the many by-products resulting from the process. Tall oil soap (TOS) is a white frothy substance created during the pulping process. It contains chemicals that can be extracted for use in other industries. The processing of TOS results in a product called spent TOS. This study examined the incineration process to derive process heat from the calorific value in spent TOS. Brais Malouin and Associates (BMA) proposed that an atomizing nozzle should be used for use with this liquid in an incinerating burner. The efficiency of atomization of spent TOS with the BMA nozzle was determined by the Canada Centre for Mineral and Energy Technology (CANMET), which also characterized the combustion in a simulated boiler situation. The combustion tests were performed in the Pilot-Scale Research Boiler at the CANMET Energy Technology Centre (CETC). Pre-heating was done with a number 2 oil flame. Flame stability was determined by observing the flame through sight ports and by measuring the gas in the furnace. The experiments showed that spent TOS could successfully burn with a number 2 oil, in a proportion of 81 spent TOS to 19 oil mass ratio. As the amount of spent TOS was increased, the amount of sulphur dioxide, nitrogen oxide (NOx) and carbon monoxide decreased. The number 2 fuel oil was responsible for the sulphur dioxide in the exhaust. It is believed that the reduction in the carbon monoxide in the exhaust is attributable to the water-gas shift reaction. As the proportion of spent TOS increased, it was shown that the amount of NOx in the exhaust decreased rapidly. A bluish-green molten deposit formed in the furnace near the burner came from copper and manganese found in the ash of the spent TOS. 7 refs., 7 tabs., 16 figs.

  11. Experimental verification of altitude effect over thermal power in an atmospheric burner

    International Nuclear Information System (INIS)

    Amell Arrieta, Andres; Agudelo, John Ramiro; Cortes, Jaime

    1992-01-01

    Colombian national massive gasification plan is carried out in a variety of geographic altitudes ranging from 0 to 2.600 meter. The biggest market is located in the Andinan Region, which is characterized by great urban centres located at high altitudes. Commercial, domestic and industrial applications are characterized by the utilization of appliances using atmospheric burners. The thermal power of these burners is affected by altitude. This paper shows experimental results of thermal power reduction in atmospheric burners due to altitude changes. It was found that thermal power is reduced by 1,5% each 304 meters of altitude

  12. Industrial applications of Tenova FlexyTech flame-less low NOx burners

    International Nuclear Information System (INIS)

    Fantuzzi, M.; Ballarino, L.

    2008-01-01

    Environmental emissions constraints have led manufacturers to improve their low NO x recuperative burners. The development by Tenova of the FlexyTech Flame-less burners with low NO x emissions, even below the present 'Best Available Technology' limit of 40 ppm at 3% O 2 with furnace temperature 1250 C, air preheat 450 C, is described. The results achieved during the R and D programme have been also improved in the industrial installations. Some details and performances of the recent furnaces equipped with such burners are provided. (authors)

  13. Insights from field observations into controls on flow front speed in submarine sediment flows

    Science.gov (United States)

    Heerema, C.; Talling, P.; Cartigny, M.; Paull, C. K.; Gwiazda, R.; Clare, M. A.; Parsons, D. R.; Xu, J.; Simmons, S.; Maier, K. L.; Chapplow, N.; Gales, J. A.; McGann, M.; Barry, J.; Lundsten, E. M.; Anderson, K.; O'Reilly, T. C.; Rosenberger, K. J.; Sumner, E. J.; Stacey, C.

    2017-12-01

    Seafloor avalanches of sediment called turbidity currents are one of the most important processes for moving sediment across our planet. Only rivers carry comparable amounts of sediment across such large areas. Here we present some of the first detailed monitoring of these underwater flows that is being undertaken at a series of test sites. We seek to understand the factors that determine flow front speed, and how that speed varies with distance. This frontal speed is particularly important for predicting flow runout, and how the power of these hazardous flows varies with distance. First, we consider unusually detailed measurements of flow front speed defined by transit times between moorings and other tracked objects placed on the floor of Monterey Canyon offshore California in 2016-17. These measurements are then compared to flow front speeds measured using multiple moorings in Bute Inlet, British Columbia in 2016; and by cable breaks in Gaoping Canyon offshore Taiwan in 2006 and 2009. We seek to understand how flow front velocity is related to seafloor gradient, flow front thickness and density. It appears that the spatial evolution of frontal speed is similar in multiple flows, although their peak frontal velocities vary. Flow front velocity tends to increase rapidly initially before declining rather gradually over tens or even hundreds of kilometres. It has been proposed that submarine flows will exist in one of two states; either eroding and accelerating, or depositing sediment and dissipating. We conclude by discussing the implications of this global compilation of flow front velocities for understanding submarine flow behaviour.

  14. Controlling flow conditions of test filters in iodine filters

    International Nuclear Information System (INIS)

    Holmberg, R.; Laine, J.

    1979-03-01

    Several different iodine filter and test filter designs and experience gained from their operation are presented. For the flow experiments, an iodine filter system equipped with flow regulating and measuring devices was built. In the experiments the influence of the packing method of the iodine sorption material and the influence of the flow regulating and measuring divices upon the flow conditions in the test filters was studied. On the basis of the experiments it has been shown that the flows through the test filters always can be adjusted to a correct value if there only is a high enough pressure difference available across the test filter ducting. As a result of the research, several different methods are presented with which the flows through the test filters in both operating and future iodine sorption system can easily be measured and adjusted to their correct values. (author)

  15. Optimal control of algae growth by controlling CO 2 and nutrition flow using Pontryagin Maximum Principle

    Science.gov (United States)

    Mardlijah; Jamil, Ahmad; Hanafi, Lukman; Sanjaya, Suharmadi

    2017-09-01

    There are so many benefit of algae. One of them is using for renewable energy and sustainable in the future. The greater growth of algae will increasing biodiesel production and the increase of algae growth is influenced by glucose, nutrients and photosynthesis process. In this paper, the optimal control problem of the growth of algae is discussed. The objective function is to maximize the concentration of dry algae while the control is the flow of carbon dioxide and the nutrition. The solution is obtained by applying the Pontryagin Maximum Principle. and the result show that the concentration of algae increased more than 15 %.

  16. Effect of plasma actuator control parameters on a transitional flow

    Science.gov (United States)

    Das Gupta, Arnob; Roy, Subrata

    2018-04-01

    This study uses a wall-resolved implicit large eddy simulation to investigate the effects of different surface dielectric barrier discharge actuator parameters such as the geometry of the electrodes, frequency, amplitude of actuation and thermal effect. The actuator is used as a tripping device on a zero-pressure gradient laminar boundary layer flow. It is shown that the standard linear actuator creates structures like the Tollmien-Schlichting wave transition. The circular serpentine, square serpentine and spanwise actuators have subharmonic sinuous streak breakdown and behave like oblique wave transition scenario. The spanwise and square actuators cause comparably faster transition to turbulence. The square actuator adds energy into the higher spanwise wavenumber modes resulting in a faster transition compared to the circular actuator. When the Strouhal number of actuation is varied, the transition does not occur for a value below 0.292. Higher frequencies with same amplitude of actuation lead to faster transition. Small changes (<4%) in the amplitude of actuation can have a significant impact on the transition location which suggests that an optimal combination of frequency and amplitude exists for highest control authority. The thermal bumps approximating the actuator heating only shows localized effects on the later stages of transition for temperatures up to 373 K and can be ignored for standard actuators operating in subsonic regimes.

  17. Recycling flow rate control device in BWR type reactor

    International Nuclear Information System (INIS)

    Fujiwara, Tadashi; Koda, Yasushi

    1988-01-01

    Purpose: To reduce the recycling pump speed if the pressure variation width and the variation ratio in the nuclear reactor exceed predetermined values, to thereby avoid the shutdown of the plant. Constitution: There has been proposed a method of monitoring the neutron flux increase thereby avoiding unnecessary plant shutdown, but it involves a problems of reactor scram depending on the state of the plant and the set values. In view of the above, in the plant using internal pumps put under the thyristor control and having high response to recycling flow rate, the reactor pressure is monitored and the speed of the internal pump is rapidly reduced when the pressure variation width and variation ratio exceed predetermined values to reduce the reactor power and avoid the plant shutdown. This can reduce the possibility of unnecessary power reduction due to neutron flux noises or the possibility of plant shutdown under low power conditions. Further, since the reactor operation can be continued without stopping the recycling pump, the operation upon recovery can be made rapid. (Horiuchi, T.)

  18. Power flow controller with a fractionally rated back-to-back converter

    Science.gov (United States)

    Divan, Deepakraj M.; Kandula, Rajendra Prasad; Prasai, Anish

    2016-03-08

    A power flow controller with a fractionally rated back-to-back (BTB) converter is provided. The power flow controller provide dynamic control of both active and reactive power of a power system. The power flow controller inserts a voltage with controllable magnitude and phase between two AC sources at the same frequency; thereby effecting control of active and reactive power flows between the two AC sources. A transformer may be augmented with a fractionally rated bi-directional Back to Back (BTB) converter. The fractionally rated BTB converter comprises a transformer side converter (TSC), a direct-current (DC) link, and a line side converter (LSC). By controlling the switches of the BTB converter, the effective phase angle between the two AC source voltages may be regulated, and the amplitude of the voltage inserted by the power flow controller may be adjusted with respect to the AC source voltages.

  19. Active bypass flow control for a seal in a gas turbine engine

    Science.gov (United States)

    Ebert, Todd A.; Kimmel, Keith D.

    2017-01-10

    An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears. In at least one embodiment, the metering device may include a valve formed from one or more pins movable between open and closed positions in which the one pin at least partially bisects the bypass channel to regulate flow.

  20. Structural Control and Groundwater Flow in the Nubian Aquifer

    Science.gov (United States)

    Fathy, K.; Sultan, M.; Ahmed, M.; Save, H.; Emil, M. K.; Elkaliouby, B.

    2017-12-01

    An integrated research approach (remote sensing, field, geophysics) was conducted to investigate the structural control on groundwater flow in large aquifers using the less studied Nubian Sandstone Aquifer System (NSAS) of NE Africa as a test site. The aquifer extends over 2.2 x 106 km2 in Egypt, Libya, Chad, and Sudan and consists of thick (> 3 kms), water-bearing, Paleozoic and Mesozoic sandstone with intercalations of Tertiary shale and clay. It is subdivided into three sub-basins (Northern Sudan Platform [NSP], Dakhla [DAS], and Kufra) that are separated by basement uplifts (e.g., E-W trending Uweinat-Aswan uplift that separates DAS from the NSP). Aquifer recharge occurs in the south (NSP and southern Kufra) where the aquifer is unconfined and precipitation is high (Average Annual Precipitation [AAP]: 117 mm/yr.) and discharge is concentrated in the north (DAS and northern Kufra). Our approach is a three-fold exercise. Firstly, we compared GOCE-based Global Geopotential Models (GGMs) to terrestrial gravity anomalies for 21262 sites to select the optimum model for deriving Bouguer gravity anomalies. Secondly, structures and uplifts were mapped using hill shade images and their extension in the subsurface were mapped using the Eigen_6C4 model-derived Bouguer anomalies and their Tilt Derivative products (TDR). Thirdly, hydrological analysis was conducted using GRACE CSR 1° x 1° mascon solutions to investigate the mass variations in relation to the mapped structures. Our findings include: (1) The Eigen-6C4 is the optimum model having the lowest deviation (9.122 mGal) from the terrestrial gravity anomalies; (2) the surface expressions of structures matched fairly well with their postulated extensions in the subsurface; (3) identified fault systems include: Red Sea rift-related N-S to NW-SE trending grabens formed by reactivating basement structures during Red Sea opening and Syrian arc-related NE-SW trending dextral shear systems; (4) TWS patterns are uniform

  1. Computational Modeling of Flow Control Systems for Aerospace Vehicles, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Clear Science Corp. proposes to develop computational methods for designing active flow control systems on aerospace vehicles with the primary objective of...

  2. Flow Physics and Control for Internal and External Aerodynamics

    Science.gov (United States)

    Wygnanski, I.

    2010-01-01

    Exploiting instabilities rather than forcing the flow is advantageous. Simple 2D concepts may not always work. Nonlinear effects may result in first order effect. Interaction between spanwise and streamwise vortices may have a paramount effect on the mean flow, but this interaction may not always be beneficial.

  3. Controllability of Non-Newtonian Fluids Under Homogeneous Flows

    National Research Council Canada - National Science Library

    Wilson, Lynda M

    2007-01-01

    .... The constitutive models are as follows: the Phan-Thien-Tanner model; the Johnson-Segalman model; and the Doi model. The effect of extensional flow on these models and the effect of shear flow on the Doi model have not been explored previous to this work...

  4. PI2 controller based coordinated control with Redox Flow Battery and Unified Power Flow Controller for improved Restoration Indices in a deregulated power system

    Directory of Open Access Journals (Sweden)

    R. Thirunavukarasu

    2016-12-01

    Full Text Available The nature of power system restoration problem involves status assessment, optimization of generation capability and load pickup. This paper proposes the evaluation of Power System Restoration Indices (PSRI based on the Automatic Generation Control (AGC assessment of interconnected power system in a deregulated environment. The PSRI are useful for system planners to prepare the power system restoration plans and to improve the efficiency of the physical operation of the power system with the increased transmission capacity in the network. The stabilization of frequency and tie-line power oscillations in an interconnected power system becomes challenging when implemented in the future competitive environment. This paper also deals with the concept of AGC in two-area reheat power system having coordinated control action with Redox Flow Battery (RFB and Unified Power Flow Controller (UPFC are capable of controlling the network performance in a very fast manner and improve power transfer limits in order to have a better restoration. In addition to that a new Proportional–Double Integral (PI2 controller is designed and implemented in AGC loop and controller parameters are optimized through Bacterial Foraging Optimization (BFO algorithm. Simulation results reveal that the proposed PI2 controller is that it has good stability during load variations, excellent transient and dynamic responses when compared with the system comprising PI controller. Moreover the AGC loop with RFB coordinated with UPFC has greatly improved the dynamic response and it reduces the control input requirements, to ensure improved PSRI in order to provide the reduced restoration time, thereby improving the system reliability.

  5. Behaviors of tribrachial edge flames and their interactions in a triple-port burner

    KAUST Repository

    Yamamoto, Kazuhiro; Isobe, Yusuke; Hayashi, Naoki; Yamashita, Hiroshi; Chung, Suk-Ho

    2015-01-01

    In a triple-port burner, various non-premixed flames have been observed previously. Especially for the case with two lifted flames, such configuration could be suitable in studying interaction between two tribrachial flames. In the present study

  6. Time evolution of propagating nonpremixed flames in a counterflow, annular slot burner under AC electric fields

    KAUST Repository

    Tran, Vu Manh; Cha, Min

    2016-01-01

    alternating current electric fields to a gap between the upper and lower parts of a counterflow, annular slot burner and present the characteristics of the propagating nonpremixed edge-flames produced. Contrary to many other previous studies, flame

  7. Burning low volatile fuel in tangentially fired furnaces with fuel rich/lean burners

    International Nuclear Information System (INIS)

    Wei Xiaolin; Xu Tongmo; Hui Shien

    2004-01-01

    Pulverized coal combustion in tangentially fired furnaces with fuel rich/lean burners was investigated for three low volatile coals. The burners were operated under the conditions with varied value N d , which means the ratio of coal concentration of the fuel rich stream to that of the fuel lean stream. The wall temperature distributions in various positions were measured and analyzed. The carbon content in the char and NO x emission were detected under various conditions. The new burners with fuel rich/lean streams were utilized in a thermal power station to burn low volatile coal. The results show that the N d value has significant influences on the distributions of temperature and char burnout. There exists an optimal N d value under which the carbon content in the char and the NO x emission is relatively low. The coal ignition and NO x emission in the utilized power station are improved after retrofitting the burners

  8. Estimating drain flow from measured water table depth in layered soils under free and controlled drainage

    Science.gov (United States)

    Saadat, Samaneh; Bowling, Laura; Frankenberger, Jane; Kladivko, Eileen

    2018-01-01

    Long records of continuous drain flow are important for quantifying annual and seasonal changes in the subsurface drainage flow from drained agricultural land. Missing data due to equipment malfunction and other challenges have limited conclusions that can be made about annual flow and thus nutrient loads from field studies, including assessments of the effect of controlled drainage. Water table depth data may be available during gaps in flow data, providing a basis for filling missing drain flow data; therefore, the overall goal of this study was to examine the potential to estimate drain flow using water table observations. The objectives were to evaluate how the shape of the relationship between drain flow and water table height above drain varies depending on the soil hydraulic conductivity profile, to quantify how well the Hooghoudt equation represented the water table-drain flow relationship in five years of measured data at the Davis Purdue Agricultural Center (DPAC), and to determine the impact of controlled drainage on drain flow using the filled dataset. The shape of the drain flow-water table height relationship was found to depend on the selected hydraulic conductivity profile. Estimated drain flow using the Hooghoudt equation with measured water table height for both free draining and controlled periods compared well to observed flow with Nash-Sutcliffe Efficiency values above 0.7 and 0.8 for calibration and validation periods, respectively. Using this method, together with linear regression for the remaining gaps, a long-term drain flow record for a controlled drainage experiment at the DPAC was used to evaluate the impacts of controlled drainage on drain flow. In the controlled drainage sites, annual flow was 14-49% lower than free drainage.

  9. Flujo de control en iOS Flow control in iOS

    Directory of Open Access Journals (Sweden)

    Franklin Hernández Castro

    2012-11-01

    Full Text Available El objetivo de este artículo es explicar los flujos de control que se usan en la programación de las aplicaciones en iOS, con el fin de resumir los aspectos más relevantes que se deben tomar en cuenta para programar una tarea a ser realizada por un dispositivo móvil del tipo iPhone o iPad. Debido a que el ambiente iOS es estrictamente orientado a objetos (OOP, los flujos de control no son obvios; además, los estándares de la firma Apple® definen patrones de diseño en el sistema que son altamente recomendados en este tipo de diseño. En este artículo se introducen algunos de ellos.This paper explain the control flows that are used by programming applications in iOS, trying to summarize the most important aspects to be considered by programming mobile devices like iPhone and iPad. Because iOS environment, is strictly a object-oriented one(OOP, control flows are not obvious, besides Apple® use design patterns highly recommended in this type of programming. Here we introduces some of them.

  10. Controlling Subsurface Fractures and Fluid Flow: A Basic Research Agenda

    Energy Technology Data Exchange (ETDEWEB)

    Pyrak-Nolte, Laura J [Purdue Univ., West Lafayette, IN (United States); DePaolo, Donald J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Pietraß, Tanja [USDOE Office of Science, Washington, DC (United States)

    2015-05-22

    From beneath the surface of the earth, we currently obtain about 80-percent of the energy our nation consumes each year. In the future we have the potential to generate billions of watts of electrical power from clean, green, geothermal energy sources. Our planet’s subsurface can also serve as a reservoir for storing energy produced from intermittent sources such as wind and solar, and it could provide safe, long-term storage of excess carbon dioxide, energy waste products and other hazardous materials. However, it is impossible to underestimate the complexities of the subsurface world. These complexities challenge our ability to acquire the scientific knowledge needed for the efficient and safe exploitation of its resources. To more effectively harness subsurface resources while mitigating the impacts of developing and using these resources, the U.S. Department of Energy established SubTER – the Subsurface Technology and Engineering RD&D Crosscut team. This DOE multi-office team engaged scientists and engineers from the national laboratories to assess and make recommendations for improving energy-related subsurface engineering. The SubTER team produced a plan with the overall objective of “adaptive control of subsurface fractures and fluid flow.”This plan revolved around four core technological pillars—Intelligent Wellbore Systems that sustain the integrity of the wellbore environment; Subsurface Stress and Induced Seismicity programs that guide and optimize sustainable energy strategies while reducing the risks associated with subsurface injections; Permeability Manipulation studies that improve methods of enhancing, impeding and eliminating fluid flow; and New Subsurface Signals that transform our ability to see into and characterize subsurface systems. The SubTER team developed an extensive R&D plan for advancing technologies within these four core pillars and also identified several areas where new technologies would require additional basic research

  11. Investigation of co-flow jet flow control and its applications

    Science.gov (United States)

    Lefebvre, Alexis M.

    This thesis investigates the performance of co-flow jet (CFJ) flow control and its applications using experimental testing and computational fluid dynamics (CFD) simulations. For a stationary airfoil and wing, CFJ increases the lift coefficient (CL), reduces the drag and may produce thrust at a low angle of attack (AoA). The maximum lift coefficient is substantially increased for a 2D CFJ airfoil and reaches a value of 4.8 at Cmicro = 0.30. The power consumption of the CFJ pump, measured by the power coefficient (Pc), is influenced by a variety of parameters, including the momentum coefficient (C micro ), the AoA, the injection slot location, and the internal cavity configuration. A low Cmicro of 0.04 produces a rather small Pc in the range of 0.01--0.02 while a higher Cmicro rapidly increases the Pc. Due to the stronger leading edge suction effect, increasing the AoA decreases the Pc. That is until the flow is near separation, within about 2°--3° of the stall AoA. An injection slot location within 2%--5% chord from the leading edge very effectively reduces the power coefficient. An internal cavity design with no separation is crucial to minimize the CFJ power consumption. Overall, the CFJ effectiveness is enhanced with an increasing Mach number as long as the flow remains subsonic, typically with free stream Mach number less than 0.4. Two pitching airfoil oscillations with dynamic stall are studied in this thesis, namely the mild dynamic stall and the deep dynamic stall. At Mach 0.3, the CFJ with a relatively low Cmicro of 0.08 removes the mild dynamic stall. Thereby, the time-averaged lift is increased by 32% and the time-averaged drag is decreased by 80%. The resulting time-averaged aerodynamic (L/D)ave, which does not take the pumping power into account, reaches 118.3. When C micro is increased, the time-averaged drag becomes negative, which demonstrates the feasibility of a CFJ to propel helicopter blades using its pump as the only source of power. The deep

  12. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner

    Directory of Open Access Journals (Sweden)

    Yik Siang Pang

    2018-01-01

    Full Text Available This paper presents a Computational Fluid Dynamics (CFD study of a natural gas combustion burner focusing on the effect of combustion, thermal radiation and turbulence models on the temperature and chemical species concentration fields. The combustion was modelled using the finite rate/eddy dissipation (FR/EDM and partially premixed flame models. Detailed chemistry kinetics CHEMKIN GRI-MECH 3.0 consisting of 325 reactions was employed to model the methane combustion. Discrete ordinates (DO and spherical harmonics (P1 model were employed to predict the thermal radiation. The gas absorption coefficient dependence on the wavelength is resolved by the weighted-sum-of-gray-gases model (WSGGM. Turbulence flow was simulated using Reynolds-averaged Navier-Stokes (RANS based models. The findings showed that a combination of partially premixed flame, P1 and standard k-ε (SKE gave the most accurate prediction with an average deviation of around 7.8% of combustion temperature and 15.5% for reactant composition (methane and oxygen. The results show the multi-step chemistry in the partially premixed model is more accurate than the two-step FR/EDM. Meanwhile, inclusion of thermal radiation has a minor effect on the heat transfer and species concentration. SKE turbulence model yielded better prediction compared to the realizable k-ε (RKE and renormalized k-ε (RNG. The CFD simulation presented in this work may serve as a useful tool to evaluate a performance of a natural gas combustor. Copyright © 2018 BCREC Group. All rights reserved Received: 26th July 2017; Revised: 9th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Pang, Y.S., Law, W.P., Pung, K.Q., Gimbun, J. (2018. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 155-169 (doi:10.9767/bcrec

  13. Frequency tuning allows flow direction control in microfluidic networks with passive features.

    Science.gov (United States)

    Jain, Rahil; Lutz, Barry

    2017-05-02

    Frequency tuning has emerged as an attractive alternative to conventional pumping techniques in microfluidics. Oscillating (AC) flow driven through a passive valve can be rectified to create steady (DC) flow, and tuning the excitation frequency to the characteristic (resonance) frequency of the underlying microfluidic network allows control of flow magnitude using simple hardware, such as an on-chip piezo buzzer. In this paper, we report that frequency tuning can also be used to control the direction (forward or backward) of the rectified DC flow in a single device. Initially, we observed that certain devices provided DC flow in the "forward" direction expected from previous work with a similar valve geometry, and the maximum DC flow occurred at the same frequency as a prominent peak in the AC flow magnitude, as expected. However, devices of a slightly different geometry provided the DC flow in the opposite direction and at a frequency well below the peak AC flow. Using an equivalent electrical circuit model, we found that the "forward" DC flow occurred at the series resonance frequency (with large AC flow peak), while the "backward" DC flow occurred at a less obvious parallel resonance (a valley in AC flow magnitude). We also observed that the DC flow occurred only when there was a measurable differential in the AC flow magnitude across the valve, and the DC flow direction was from the channel with large AC flow magnitude to that with small AC flow magnitude. Using these observations and the AC flow predictions from the equivalent circuit model, we designed a device with an AC flowrate frequency profile that was expected to allow the DC flow in opposite directions at two distinct frequencies. The fabricated device showed the expected flow reversal at the expected frequencies. This approach expands the flow control toolkit to include both magnitude and direction control in frequency-tuned microfluidic pumps. The work also raises interesting questions about the

  14. Mathematical model of stacked one-sided arrangement of the burners

    Directory of Open Access Journals (Sweden)

    Oraz J.A.

    2017-01-01

    Full Text Available Paper is aimed at computer simulation of the turbulent methane-air combustion in upgraded U-shaped boiler unit. To reduce the temperature in the flame and hence NOx release every burner output was reduced, but the number of the burners was increased. The subject of studying: complex of characteristics with space-time fields in the upgraded steam boiler E-370 with natural circulation. The flare structure, temperature and concentrations were determined computationally.

  15. Ammonia-methane combustion in tangential swirl burners for gas turbine power generation

    OpenAIRE

    Valera Medina, Agustin; Marsh, Richard; Runyon, Jon; Pugh, Daniel; Beasley, Paul; Hughes, Timothy Richard; Bowen, Philip John

    2017-01-01

    Ammonia has been proposed as a potential energy storage medium in the transition towards a low-carbon economy. This paper details experimental results and numerical calculations obtained to progress towards optimisation of fuel injection and fluidic stabilisation in swirl burners with ammonia as the primary fuel. A generic tangential swirl burner has been employed to determine flame stability and emissions produced at different equivalence ratios using ammonia–methane blends. Experiments were...

  16. Duct burners in heat recovery system for cogeneration and captive power plants

    International Nuclear Information System (INIS)

    Majumdar, J.

    1992-01-01

    Our oil explorations both onshore and offshore have thrown open bright prospects of cogeneration by using natural gas in gas turbine power plants with heat recovery units. Both for co-gen and combined cycle systems, supplementary firing of GT exhaust gas is normally required. Hence, duct burners have significant role for effective contribution towards of efficacy of heat recovery system for gas turbine exhaust gas. This article details on various aspects of duct burners in heat recovery systems. (author)

  17. Numerical Simulation of the Thermal Process in a W-Shape Radiant Tube Burner

    Science.gov (United States)

    Wang, Yi; Li, Jiyong; Zhang, Lifeng; Ling, Haitao; Li, Yanlong

    2014-07-01

    In the current work, three-dimensional mathematical models were developed for the heat transfer and combustion in a W-shape radiant tube burner (RTB) and were solved using Fluent software (ANSYS Inc., Canonsburg, PA). The standard k- ɛ model, nonpremixed combustion model, and the discrete ordinate model were used for the modeling of turbulence, combustion, and radiant heat transfer, respectively. In addition, the NO x postprocessor was used for the prediction of the NO emission. A corresponding experiment was performed for the validation of mathematical models. The details of fluid flow, heat transfer, and combustion in the RTB were investigated. Moreover, the effect of the air/fuel ratio (A/F) and air staging on the performance of RTB was studied with the reference indexes including heat efficiency, maximum temperature difference on shell wall, and NO emission at the outlet. The results indicated that a low speed zone formed in the vicinity of the combustion chamber outlet, and there were two relative high-temperature zones in the RTB, one in combustion chamber that favored the flame stability and the other from the main flame in the RTB. The maximum temperature difference was 95.48 K. As the A/F increased, the temperature increased first and then decreased. As the ratio of the primary to secondary air increased, the recirculation zone at the outlet of combustion chamber shrank gradually to disappear, and the flame length was longer and the temperature in flame decreased correspondingly.

  18. Time evolution of propagating nonpremixed flames in a counterflow, annular slot burner under AC electric fields

    KAUST Repository

    Tran, Vu Manh

    2016-06-19

    The mechanism behind improved flame propagation speeds under electric fields is not yet fully understood. Although evidence supports that ion movements cause ionic wind, how this wind affects flame propagation has not been addressed. Here, we apply alternating current electric fields to a gap between the upper and lower parts of a counterflow, annular slot burner and present the characteristics of the propagating nonpremixed edge-flames produced. Contrary to many other previous studies, flame displacement speed decreased with applied AC voltage, and, depending on the applied AC frequency, the trailing flame body took on an oscillatory wavy motion. When flame displacement speeds were corrected using measured unburned flow velocities, we found no significant difference in flame propagation speeds, indicating no thermal or chemical effects by electric fields on the burning velocity. Thus, we conclude that the generation of bidirectional ionic wind is responsible for the impact of electric fields on flames and that an interaction between this bidirectional ionic wind and the flame parameters creates visible and/or measurable phenomenological effects. We also explain that the presence of trailing flame bodies is a dynamic response to an electric body force on a reaction zone, an area that can be considered to have a net positively charged volume. In addition, we characterize the wavy motion of the transient flame as a relaxation time independent of mixture strength, strain rate, and Lewis number.

  19. Effect of pulsation on the near flow field of a submerged water jet

    Indian Academy of Sciences (India)

    HAREKRISHNA YADAV

    2018-03-22

    Mar 22, 2018 ... Department of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai ... combustion engines, industrial type burners, drying of food, ... visualized the fluid flow characteristic using a smoke-wire.

  20. A congestion line flow control in deregulated power system

    Directory of Open Access Journals (Sweden)

    Venkatarajan Shanmuga Sundaram

    2011-01-01

    Full Text Available Under open access, market-driven transactions have become the new independent decision variables defining the behavior of the power system. The possibility of transmission lines getting over-loaded is relatively more under deregulated operation because different parts of the system are owned by separate companies and in part operated under varying service charges. This paper discusses a two-tier algorithm for correcting the lone overloads in conjunction with the conventional power-flow methods. The method uses line flow sensitivities, which are computed by the East Decoupled Power-flow algorithm and can be adapted for on-line implementation.

  1. Numerical Studies of a Supersonic Fluidic Diverter Actuator for Flow Control

    Science.gov (United States)

    Gokoglu, Suleyman A.; Kuczmarski, Maria A.; Culley, Dennis e.; Raghu, Surya

    2010-01-01

    The analysis of the internal flow structure and performance of a specific fluidic diverter actuator, previously studied by time-dependent numerical computations for subsonic flow, is extended to include operation with supersonic actuator exit velocities. The understanding will aid in the development of fluidic diverters with minimum pressure losses and advanced designs of flow control actuators. The self-induced oscillatory behavior of the flow is successfully predicted and the calculated oscillation frequencies with respect to flow rate have excellent agreement with our experimental measurements. The oscillation frequency increases with Mach number, but its dependence on flow rate changes from subsonic to transonic to supersonic regimes. The delay time for the initiation of oscillations depends on the flow rate and the acoustic speed in the gaseous medium for subsonic flow, but is unaffected by the flow rate for supersonic conditions

  2. Design evaluation of the 20-cm (8-inch) secondary burner system

    International Nuclear Information System (INIS)

    Rode, J.S.

    1977-08-01

    This report describes an evaluation of the design of the existing 20-cm (8-inch) engineering-scale secondary burner system in the HTGR reprocessing cold pilot plant at General Atomic Co. The purpose of this evaluation is to assess the suitability of the existing design as a prototype of the HTGR Recycle Demonstration Facility (HRDF) secondary burner system and to recommend alternatives where the existing design is thought to be unsuitable as a prototype. This evaluation has led to recommendations for the parallel development of two integrated design concepts for a prototype secondary burner system. One concept utilizes the existing burner heating and cooling subsystems in order to minimize development risk, but simplifies a number of other features associated with remote maintenance and burner operation. The other concept, which offers maximum cost reduction, utilizes internal gas cooling of the burner, retains the existing heating subsystem for design compatibility, but requires considerable development to reduce the risk to acceptable limits. These concepts, as well as other design alternatives, are described and evaluated

  3. Design evaluation of the 40-cm (16-inch) primary burner system

    International Nuclear Information System (INIS)

    Rode, J.S.

    1977-06-01

    An evaluation is given of the design of the existing 40-cm (16-in.) engineering-scale primary burner system in the HTGR reprocessing cold pilot plant at General Atomic Co. The purpose of this evaluation is to assess the suitability of the existing design as a prototype of the HTGR Recycle Demonstration Facility (HRDF) primary burner system and to recommend alternatives where the existing design is thought to be unsuitable as a prototype. This evaluation has led to recommendations for the parallel development of two integrated design concepts for a prototype primary burner system. One concept utilizes the existing burner heating and cooling sub-systems in order to minimize development risk, but simplifies a number of other features associated with remote maintenance and burner operation. The other concept, which offers maximum cost reduction, utilizes direct contact hot gas heating and internal gas cooling of the burner, but requires considerable development to reduce the risk to acceptable limits. These concepts, as well as other design alternatives, are described and evaluated

  4. Power flow control strategy in distribution network for dc type distributed energy resource at load bus

    International Nuclear Information System (INIS)

    Hanif, A.; Choudhry, M.A.

    2013-01-01

    This research work presents a feed forward power flow control strategy in the secondary distribution network working in parallel with a DC type distributed energy resource (DER) unit with SPWM-IGBT Voltage Source Converter (VSC). The developed control strategy enables the VSC to be used as power flow controller at the load bus in the presence of utility supply. Due to the investigated control strategy, power flow control from distributed energy resource (DER) to common load bus is such that power flows to the load without facing any power quality problem. The technique has an added advantage of controlling power flow without having a dedicated power flow controller. The SPWM-IGBT VSC is serving the purpose of dc-ac converter as well as power flow controller. Simulations for a test system using proposed power flow control strategy are carried out using SimPower Systems toolbox of MATLAB at the rate and Simulink at the rate. The results show that a reliable, effective and efficient operation of DC type DER unit in coordination with main utility network can be achieved. (author)

  5. Flow rate control systems for coolants for BWR type reactors

    International Nuclear Information System (INIS)

    Igarashi, Yoko; Kato, Naoyoshi.

    1981-01-01

    Purpose: To increase spontaneous recycling flow rate of coolants in BWR type reactors when the water level in the reactor decreases, by communicating a downcomer with a lower plenum. Constitution: An opening is provided to the back plate disposed at the lower end of a reactor core shroud for communicating a downcomer with a lower plenum, and an ON-OFF valve actuated by an operation rod is provided to the opening. When abnormal water level or pressure in the reactor is detected by a level metal or pressure meter, the operation rod is driven to open the ON-OFF valve, whereby coolants fed from a jet pump partially flows through the opening to increase the spontaneous recycling flow rate of the coolants. This can increase the spontaneous recycling flow rate of the coolants upon spontaneous recycling operation, thereby maintaining the reactor safety and the fuel soundness. (Moriyama, K.)

  6. Electro-Magnetic Flow Control to Enable Natural Laminar Flow Wings

    Data.gov (United States)

    National Aeronautics and Space Administration — This research team has developed a solid-state electromagnetic device that, when embedded along the leading edge of an aircraft wing, can disrupt laminar air flow on...

  7. Active bypass flow control for a seal in a gas turbine engine

    Science.gov (United States)

    Ebert, Todd A.; Kimmel, Keith D.

    2017-03-14

    An active bypass flow control system for controlling bypass compressed air based upon leakage flow of compressed air flowing past an outer balance seal between a stator and rotor of a first stage of a gas turbine in a gas turbine engine is disclosed. The active bypass flow control system is an adjustable system in which one or more metering devices may be used to control the flow of bypass compressed air as the flow of compressed air past the outer balance seal changes over time as the outer balance seal between the rim cavity and the cooling cavity wears In at least one embodiment, the metering device may include an annular ring having at least one metering orifice extending therethrough, whereby alignment of the metering orifice with the outlet may be adjustable to change a cross-sectional area of an opening of aligned portions of the outlet and the metering orifice.

  8. Effect Of Steel Flow Control Devices On Flow And Temperature Field In The Tundish Of Continuous Casting Machine

    Directory of Open Access Journals (Sweden)

    Sowa L.

    2015-06-01

    Full Text Available The mathematical model and numerical simulations of the liquid steel flow in a tundish are presented in this paper. The problem was treated as a complex and solved by the finite element method. One takes into consideration in the mathematical model the changes of thermophysical parameters depending on the temperature. The single-strand tundish is used to casting slabs. The internal work space of the tundish was modified by flow control devices. The first device was a pour pad situated in the pouring tundish zone. The second device was a dam. The third device was a baffle with three holes. The dam and baffle were placed in the tundish at different positions depending on the variant. The main purpose of using these was to put barriers in the steel flow path as well as give directional metal flow upwards which facilitated inclusion floatation. The interaction of flow control devices on hydrodynamic conditions was received from numerical simulations. As a result of the computations carried out, the liquid steel flow and steel temperature fields were obtained. The influences of the tundish modifications on the velocity fields in liquid phase of the steel were estimated, because these have essential an influence on high-quality of a continuous steel cast slab.

  9. An iterative method for controlling reactive power flow in boundary transformers

    Energy Technology Data Exchange (ETDEWEB)

    Trigo, Angel L.; Martinez, Jose L.; Riquelme, Jesus; Romero, Esther [Department of Electrical Engineering, University of Seville (Spain)

    2011-02-15

    This paper presents an operational tool designed to help the system operator to control the reactive power flow in transmission-subtransmission boundary transformers. The main objective is to determine the minimum number of control actions necessary to ensure that reactive power flows in transmission/subtransmission transformers remain within limits. The proposed iterative procedure combines the use of a linear programming problem and a load flow tool. The linear programming assumes a linear behaviour between dependent and control variables around an operating point, modelled with sensitivities. Experimental results regarding IEEE systems are provided comparing the performance of the proposed approach with that of a conventional optimal power flow. (author)

  10. Scenarios for control and data flows in multiprotocol over ATM

    Science.gov (United States)

    Kujoory, Ali

    1997-10-01

    The multiprotocol over ATM (MPOA), specified by the ATM Forum, provides an architecture for transfer of Internetwork layer packets (Layer 3 datagram such as IP, IPX) over ATM subnets or across the emulated LANs. MPOA provides shortcuts that bypass routers to avoid router bottlenecks. It is a grand union of some of the existing standards such as LANE by the ATM Forum, NHRP by the IETF, and the Q.2931 by ITU. The intent of this paper is to clarify the data flows between pairs of source and destination hosts in an MPOA system. It includes scenarios for both the intra- and inter-subnet flows between different pairs of MPOA end-systems. The intrasubnet flows simply use LANE for address resolution or data transfer. The inter-subnet flows may use a default path for short-lived flows or a shortcut for long-lived flows. The default path uses the LANE and router capabilities. The shortcut path uses LANE plus NHRP for ATM address resoluton. An ATM virtual circuit is established before the data transfer. This allows efficient transfer of internetwork layer packets over ATM for real-time applications.

  11. A Computed River Flow-Based Turbine Controller on a Programmable Logic Controller for Run-Off River Hydroelectric Systems

    Directory of Open Access Journals (Sweden)

    Razali Jidin

    2017-10-01

    Full Text Available The main feature of a run-off river hydroelectric system is a small size intake pond that overspills when river flow is more than turbines’ intake. As river flow fluctuates, a large proportion of the potential energy is wasted due to the spillages which can occur when turbines are operated manually. Manual operation is often adopted due to unreliability of water level-based controllers at many remote and unmanned run-off river hydropower plants. In order to overcome these issues, this paper proposes a novel method by developing a controller that derives turbine output set points from computed mass flow rate of rivers that feed the hydroelectric system. The computed flow is derived by summation of pond volume difference with numerical integration of both turbine discharge flows and spillages. This approach of estimating river flow allows the use of existing sensors rather than requiring the installation of new ones. All computations, including the numerical integration, have been realized as ladder logics on a programmable logic controller. The implemented controller manages the dynamic changes in the flow rate of the river better than the old point-level based controller, with the aid of a newly installed water level sensor. The computed mass flow rate of the river also allows the controller to straightforwardly determine the number of turbines to be in service with considerations of turbine efficiencies and auxiliary power conservation.

  12. Flow Control Research at NASA Langley in Support of High-Lift Augmentation

    Science.gov (United States)

    Sellers, William L., III; Jones, Gregory S.; Moore, Mark D.

    2002-01-01

    The paper describes the efforts at NASA Langley to apply active and passive flow control techniques for improved high-lift systems, and advanced vehicle concepts utilizing powered high-lift techniques. The development of simplified high-lift systems utilizing active flow control is shown to provide significant weight and drag reduction benefits based on system studies. Active flow control that focuses on separation, and the development of advanced circulation control wings (CCW) utilizing unsteady excitation techniques will be discussed. The advanced CCW airfoils can provide multifunctional controls throughout the flight envelope. Computational and experimental data are shown to illustrate the benefits and issues with implementation of the technology.

  13. Control of Nonlinear Coupled Electromagnetic Actuators for Active Drag Reduction in Turbulent Flow

    OpenAIRE

    Seidler, Florian; Trabert, Julius; Dück, Marcel; van Waasen, Stefan; Schiek, Michael; Abel, Dirk; Castelan, E. B.

    2016-01-01

    The research group FOR1779 “active drag reduction via wavy surface oscillations” develops robust methods for reduction of turbulent friction drag by flow control. The planned concentration on unsteady flow conditions requires a control of the electromagnetic actuator system for generation of transversal surface waves. The bars are positioned in parallel and coupled with an aluminum surface to generate a travelling wave perpendicular to the flow field. The actuator system can be approximately ...

  14. Flow-Control Systems Proof of Concept for Snowmelt Runoff at McMurdo Station, Antarctica

    Science.gov (United States)

    2017-01-01

    ER D C/ CR RE L TR -1 7- 1 Engineering for Polar Operations , Logistics, and Research (EPOLAR) Flow-Control Systems Proof of Concept for...January 2017 Flow-Control Systems Proof of Concept for Snowmelt Runoff at McMurdo Station, Antarctica Rosa Affleck U.S. Army Engineer Research and...runoff can be extreme where the flow can overwhelm both the drainage system and the operations and maintenance (O&M) crew. CRREL has been involved

  15. A NEW DOUBLE-SLIT CURVED WALL-JET (CWJ) BURNER FOR STABILIZING TURBULENT PREMIXED AND NON-PREMIXED FLAMES

    KAUST Repository

    Mansour, Morkous S.; Chung, Suk-Ho

    2015-01-01

    Mixing characteristics in the cold flow of non-premixed cases were first examined using acetone fluorescence technique, indicating substantial transport between the fuel and air by exhibiting appreciable premixing conditions.PIV measurements revealed that velocity gradients in the shear layers at the boundaries of the annularjets generate the turbulence, enhanced with the collisions in the interaction jet, IJ,region. Turbulent mean and rms velocities were influenced significantly by Re and high rms turbulent velocities are generated within the recirculation zone improving the flame stabilization in this burner.Premixed and non-premixed flames with high equivalence ratio were found to be more resistant to local extinction and exhibited a more corrugated and folded nature, particularly at high Re. For flames with low equivalence ratio, the processes of local quenching at IJ region and of re-ignition within merged jet region maintained these flames further downstream particularly for non-premixed methane flame, revealing a strong intermittency.

  16. Enhancement of Arterial Pressure Pulsatility by Controlling Continuous-Flow Left Ventricular Assist Device Flow Rate in Mock Circulatory System.

    Science.gov (United States)

    Bozkurt, Selim; van de Vosse, Frans N; Rutten, Marcel C M

    Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump. A mock circulation containing two synchronized servomotor-operated piston pumps acting as left and right ventricles was used as a circulatory system. Proportional-integral control was used as the control method. First, the CF-LVAD was operated at a constant speed. With pulsatile-speed CF-LVAD assistance, the pump was driven such that the same mean pump output was generated. Continuous and pulsatile-speed CF-LVAD assistance provided the same mean arterial pressure and flow rate, while the index of pulsatility increased significantly for both arterial pressure and pump flow rate signals under pulsatile speed pump support. This study shows the possibility of improving the pulsatility of CF-LVAD support by regulating pump speed over a cardiac cycle without reducing the overall level of support.

  17. AC field effect flow control of EOF in complex microfluidic systems with integrated electrodes

    NARCIS (Netherlands)

    van der Wouden, E.J.; Pennathur, S.; van den Berg, Albert; Locascio, L.E.; Gaitan, M.; Paegel, B.M.; Ross, D.J.; Vreeland, W.N.

    2008-01-01

    In this work, we demonstrate that positive net flow can be induced and controlled with relatively low potential due to the parallel alignment of the integrated channel electrodes. Therefore, we present a novel method to exquisitely control Electro Osmotic Flow (EOF) by using integrated electrodes

  18. Routing power flows in distribution networks using locally controlled power electronics

    NARCIS (Netherlands)

    Hamelink, J.; Nguyen, P.H.; Kling, W.L.; Ribeiro, P.F.; Groot, de R.J.W.

    2012-01-01

    The power grid has gradually changed its operation during the recent decades. These developments have encouraged a shift from centralized to decentralized power flow control. A research has been carried out to investigate the possibilities to control power flows using the Smart Power Router (SPR) in

  19. Inter-eNB Flow Control for Heterogeneous Networks with Dual Connectivity

    DEFF Research Database (Denmark)

    Wang, Hua; Rosa, Claudio; Pedersen, Klaus I.

    2015-01-01

    the gain provided by DC, an efficient flow control of data between the involved macro and small cell eNBs is proposed. It is demonstrated how proper configuration of the proposed flow control algorithm offers efficient trade-offs between reducing the probability that one of the eNBs involved in the DC runs...

  20. Field effect control of electro-osmotic flow in microfluidic networks

    NARCIS (Netherlands)

    van der Wouden, E.J.

    2006-01-01

    This thesis describes the development of a Field Effect Flow Control (FEFC) system for the control of Electro Osmotic Flow (EOF) in microfluidic networks. For this several aspects of FEFC have been reviewed and a process to fabricate microfluidic channels with integrated electrodes has been

  1. Control-flow analysis of function calls and returns by abstract interpretation

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Jensen, Thomas P.

    2012-01-01

    Abstract interpretation techniques are used to derive a control-flow analysis for a simple higher-order functional language. The analysis approximates the interprocedural control-flow of both function calls and returns in the presence of first-class functions and tail-call optimization. In additi...... a rational reconstruction of a constraint-based CFA from abstract interpretation principles....

  2. Numerical simulations for the coal/oxidant distribution effects between two-stages for multi opposite burners (MOB) gasifier

    International Nuclear Information System (INIS)

    Unar, Imran Nazir; Wang, Lijun; Pathan, Abdul Ghani; Mahar, Rasool Bux; Li, Rundong; Uqaili, M. Aslam

    2014-01-01

    Highlights: • We simulated a double stage 3D entrained flow coal gasifier with multi-opposite burners. • The various reaction mechanisms have evaluated with experimental results. • The effects of coal and oxygen distribution between two stages on the performance of gasifier have investigated. • The local coal to oxygen ratio is affecting the overall efficiency of gasifier. - Abstract: A 3D CFD model for two-stage entrained flow dry feed coal gasifier with multi opposite burners (MOB) has been developed in this paper. At each stage two opposite nozzles are impinging whereas the two other opposite nozzles are slightly tangential. Various numerical simulations were carried out in standard CFD software to investigate the impacts of coal and oxidant distributions between the two stages of the gasifier. Chemical process was described by Finite Rate/Eddy Dissipation model. Heterogeneous and homogeneous reactions were defined using the published kinetic data and realizable k–ε turbulent model was used to solve the turbulence equations. Gas–solid interaction was defined by Euler–Lagrangian frame work. Different reaction mechanism were investigated first for the validation of the model from published experimental results. Then further investigations were made through the validated model for important parameters like species concentrations in syngas, char conversion, maximum inside temperature and syngas exit temperature. The analysis of the results from various simulated cases shows that coal/oxidant distribution between the stages has great influence on the overall performance of gasifier. The maximum char conversion was found 99.79% with coal 60% and oxygen 50% of upper level of injection. The minimum char conversion was observed 95.45% at 30% coal with 40% oxygen at same level. In general with oxygen and coal above or equal to 50% of total at upper injection level has shown an optimized performance

  3. Premixed Combustion of Coconut Oil on Perforated Burner

    Directory of Open Access Journals (Sweden)

    I.K.G. Wirawan

    2013-10-01

    Full Text Available Coconut oil premixed combustion behavior has been studied experimentally on perforated burner with equivalence ratio (φ varied from very lean until very rich. The results showed that burning of glycerol needs large number of air so that the laminar burning velocity (SL is the highest at very lean mixture and the flame is in the form of individual Bunsen flame on each of the perforated plate hole. As φ is increased the  SL decreases and the secondary Bunsen flame with open tip occurs from φ =0.54 at the downstream of perforated flame. The perforated flame disappears at φ = 0.66 while the secondary Bunsen flame still exist with SL increases following that of hexadecane flame trend and then extinct when the equivalence ratio reaches one or more. Surrounding ambient air intervention makes SL decreases, shifts lower flammability limit into richer mixture, and performs triple and cellular flames. The glycerol diffusion flame radiation burned fatty acids that perform cellular islands on perforated hole.  Without glycerol, laminar flame velocity becomes higher and more stable as perforated flame at higher φ. At rich mixture the Bunsen flame becomes unstable and performs petal cellular around the cone flame front. Keywords: cellular flame; glycerol; perforated flame;secondary Bunsen flame with open tip; triple flame

  4. Residence Time Distributions in a Cold, Confined Swirl Flow

    DEFF Research Database (Denmark)

    Lans, Robert Pieter Van Der; Glarborg, Peter; Dam-Johansen, Kim

    1997-01-01

    Residence time distributions (RTD) in a confined, cold swirling flow have been measured with a fast-response probe and helium as a tracer. The test-rig represented a scaled down version of a burner. The effect of variation of flow velocities and swirl angle on the flow pattern in the near...

  5. Controlling mixing and segregation in time periodic granular flows

    Science.gov (United States)

    Bhattacharya, Tathagata

    Segregation is a major problem for many solids processing industries. Differences in particle size or density can lead to flow-induced segregation. In the present work, we employ the discrete element method (DEM)---one type of particle dynamics (PD) technique---to investigate the mixing and segregation of granular material in some prototypical solid handling devices, such as a rotating drum and chute. In DEM, one calculates the trajectories of individual particles based on Newton's laws of motion by employing suitable contact force models and a collision detection algorithm. Recently, it has been suggested that segregation in particle mixers can be thwarted if the particle flow is inverted at a rate above a critical forcing frequency. Further, it has been hypothesized that, for a rotating drum, the effectiveness of this technique can be linked to the probability distribution of the number of times a particle passes through the flowing layer per rotation of the drum. In the first portion of this work, various configurations of solid mixers are numerically and experimentally studied to investigate the conditions for improved mixing in light of these hypotheses. Besides rotating drums, many studies of granular flow have focused on gravity driven chute flows owing to its practical importance in granular transportation and to the fact that the relative simplicity of this type of flow allows for development and testing of new theories. In this part of the work, we observe the deposition behavior of both mono-sized and polydisperse dry granular materials in an inclined chute flow. The effects of different parameters such as chute angle, particle size, falling height and charge amount on the mass fraction distribution of granular materials after deposition are investigated. The simulation results obtained using DEM are compared with the experimental findings and a high degree of agreement is observed. Tuning of the underlying contact force parameters allows the achievement

  6. Preliminary Results on the Effects of Distributed Aluminum Combustion Upon Acoustic Growth Rates in a Rijke Burner

    OpenAIRE

    Newbold, Brian R.

    1998-01-01

    Distributed particle combustion in solid propellant rocket motors may be a significant cause of acoustic combustion instability. A Rijke burner has been developed as a tool to investigate the phenomenon. Previous improvements and characterization of the upright burner lead to the addition of a particle injection flame. The injector flame increases the burner's acoustic driving by about 10% which is proportional to the injector's additional 2 g/min of gas. Frequency remained fairly constant fo...

  7. Using artificial intelligence to control fluid flow computations

    Science.gov (United States)

    Gelsey, Andrew

    1992-01-01

    Computational simulation is an essential tool for the prediction of fluid flow. Many powerful simulation programs exist today. However, using these programs to reliably analyze fluid flow and other physical situations requires considerable human effort and expertise to set up a simulation, determine whether the output makes sense, and repeatedly run the simulation with different inputs until a satisfactory result is achieved. Automating this process is not only of considerable practical importance but will also significantly advance basic artificial intelligence (AI) research in reasoning about the physical world.

  8. Use of integrity control and automatic start of reserve in a multi-channel temperature and flow rate control device

    International Nuclear Information System (INIS)

    Strzalkowski, L.

    1975-01-01

    A way to increase reliability of process quantity control is control of the integrity of the control plants themselves. The possibilities of integrity control on control devices having simply duplicated control channels or working on the basis of the ''two-from-three'' principle are valued. A highly reliable integrity control is possible by use of test signals. For an appropriate control device, structure and function of the assemblies are described. The integrity control device may be used in the water coolant temperature and flow rate control system for all technological channels of the research reactor ''Maria''

  9. Microprocessor Based Temperature Control of Liquid Delivery with Flow Disturbances.

    Science.gov (United States)

    Kaya, Azmi

    1982-01-01

    Discusses analytical design and experimental verification of a PID control value for a temperature controlled liquid delivery system, demonstrating that the analytical design techniques can be experimentally verified by using digital controls as a tool. Digital control instrumentation and implementation are also demonstrated and documented for…

  10. Thermo-Acoustic Properties of a Burner with Axial Temperature Gradient: Theory and Experiment

    Directory of Open Access Journals (Sweden)

    Béla Kosztin

    2013-03-01

    Full Text Available This paper presents a model for thermo-acoustic effects in a gas turbine combustor. A quarter-wavelength burner with rectangular cross-section has been built and studied from an experimental and theoretical perspective. It has a premixed methane-air flame, which is held by a bluff body, and spans the width of the burner. The flame is compact, i.e. its length is much smaller than that of the burner. The fundamental mode of the burner is unstable; its frequency and pressure distribution have been measured. The complex pressure reflection coefficients at the upstream and downstream end of the burner were also measured. For the theoretical considerations, we divide the burner into three regions (the cold pre-combustion chamber, the flame region and the hot outlet region, and assume one-dimensional acoustic wave propagation in each region. The acoustic pressure and velocity are assumed continuous across the interface between the precombustion chamber and flame region, and across the interface between the flame region and outlet region. The burner ends are modelled by the measured pressure reflection coefficients. The mean temperature is assumed to have the following profile: uniformly cold and uniformly hot in the pre-combustion chamber and outlet region, respectively, and rising continuously from cold to hot in the flame region. For comparison, a discontinuous temperature profile, jumping directly from cold to hot, is also considered. The eigenfrequencies are calculated, and the pressure distribution of the fundamental mode is predicted. There is excellent agreement with the experimental results. The exact profile of the mean temperature in the flame region is found to be unimportant. This study gives us an experimentally validated Green's function, which is a very useful tool for further theoretical studies.

  11. Recent advances in extensional rheology: controlled flows and fracture

    DEFF Research Database (Denmark)

    Hassager, Ole; Huang, Qian

    Extensional deformation and flow occur in a number of polymer processing operations such as fiber spinning and film blowing. To understand and analyze material behavior in such operations, accurate and quantitative measurements of the rheological properties in well-defined extensional deformation...

  12. A Simple CPS Transformation of Control-Flow Information

    DEFF Research Database (Denmark)

    Damian, Daniel; Danvy, Olivier

    2002-01-01

    We build on Danvy and Nielsen's first-order program transformation into continuation-passing style (CPS) to design a new CPS transformation of flow information that is simpler and more efficient than what has been presented in previous work. The key to simplicity and efficiency is that our CPS tr...

  13. Discretionary Information Flow Control for Interaction-Oriented Specifications

    DEFF Research Database (Denmark)

    Lluch Lafuente, Alberto; Nielson, Flemming; Nielson, Hanne Riis

    2015-01-01

    system for statically checking if a system specification ensures an information flow policy. The approach is illustrated with two archetypal examples of distributed and parallel computing systems: a protocol for an identity-secured data providing service and a parallel MapReduce computation....

  14. Controlling two-phase flow in microfluidic systems using electrowetting

    NARCIS (Netherlands)

    Gu, H.

    2011-01-01

    Electrowetting (EW)-based digital microfluidic systems (DMF) and droplet-based two-phase flow microfluidic systems (TPF) with closed channels are the most widely used microfluidic platforms. In general, these two approaches have been considered independently. However, integrating the two

  15. Neurophysiological Basis of Cerebral Blood Flow Control: An ...

    African Journals Online (AJOL)

    The book describes the current understanding of cerebral blood flow ... metaoolism of the central nervous system. The brain ... in stroke it is a deficiency of the book that the clinical correlates are .... Review of Nutrition and Dietetics. Edited by ...

  16. Control algorithm for multiscale flow simulations of water

    DEFF Research Database (Denmark)

    Kotsalis, E. M.; Walther, Jens Honore; Kaxiras, E.

    2009-01-01

    We present a multiscale algorithm to couple atomistic water models with continuum incompressible flow simulations via a Schwarz domain decomposition approach. The coupling introduces an inhomogeneity in the description of the atomistic domain and prevents the use of periodic boundary conditions...

  17. Electromagnetic control of oscillating flows in a cavity

    NARCIS (Netherlands)

    Kalter, R.

    2015-01-01

    In continuous steel casting, liquid steel flows turbulently through a submerged nozzle into a thin, vertical mould. In the mould the liquid steel is cooled, such that it solidifies and plate steel is formed. On top of the liquid steel in the mould, a slag layer is present and due to the turbulent

  18. Controlled generation and use of CO in flow

    DEFF Research Database (Denmark)

    Hansen, Steffen V. F.; Wilson, Zoe E.; Ulven, Trond

    2016-01-01

    A method for the generation and use of carbon monoxide in flow chemistry has been developed. By using a tube-in-tube reactor, oxalyl chloride can be conveniently and safely hydrolyzed using a NaOH solution to generate CO in the outer stream, which then passes through AF-2400 semi-permeable inner...

  19. Flow control by combining radial pulsation and rotation of a cylinder in uniform flow

    Science.gov (United States)

    Oualli, H.; Hanchi, S.; Bouabdallah, A.; Gad-El-Hak, M.

    2008-11-01

    Flow visualizations and hot-wire measurements are carried out to study a circular cylinder undergoing simultaneous radial pulsation and rotation and placed in a uniform flow. The Reynolds number is in the range of 1,000--22,000, for which transition in the shear layers and near wake is expected. Our previous experimental and numerical investigations in this subcritical flow regime have established the existence of an important energy transfer mechanism from the mean flow to the fluctuations. Radial pulsations cause and enhance that energy transfer. Certain values of the amplitude and frequency of the pulsations lead to negative drag (i.e. thrust). The nonlinear interaction between the Magnus effect induced by the steady rotation of the cylinder and the near-wake modulated by the bluff body's pulsation leads to alteration of the omnipresent Kármán vortices and the possibility of optimizing the lift-to-drag ratio as well as the rates of heat and mass transfer. Other useful applications include the ability to enhance or suppress the turbulence intensity, and to avoid the potentially destructive lock-in phenomenon in the wake of bridges, electric cables and other structures.

  20. Engineering analysis of mass flow rate for turbine system control and design

    International Nuclear Information System (INIS)

    Yoo, Yong H.; Suh, Kune Y.

    2011-01-01

    Highlights: → A computer code is written to predict the steam mass flow rate through valves. → A test device is built to study the steam flow characteristics in the control valve. → Mass flow based methodology eases the programming and experimental procedures. → The methodology helps express the characteristics of each device of a turbine system. → The results can commercially be used for design and operation of the turbine system. - Abstract: The mass flow rate is determined in the steam turbine system by the area formed between the stem disk and the seat of the control valve. For precise control the steam mass flow rate should be known given the stem lift. However, since the thermal hydraulic characteristics of steam coming from the generator or boiler are changed going through each device, it is hard to accurately predict the steam mass flow rate. Thus, to precisely determine the steam mass flow rate, a methodology and theory are developed in designing the turbine system manufactured for the nuclear and fossil power plants. From the steam generator or boiler to the first bunch of turbine blades, the steam passes by a stop valve, a control valve and the first nozzle, each of which is connected with piping. The corresponding steam mass flow rate can ultimately be computed if the thermal and hydraulic conditions are defined at the stop valve, control valve and pipes. The steam properties at the inlet of each device are changed at its outlet due to geometry. The Compressed Adiabatic Massflow Analysis (CAMA) computer code is written to predict the steam mass flow rate through valves. The Valve Engineered Layout Operation (VELO) test device is built to experimentally study the flow characteristics of steam flowing inside the control valve with the CAMA input data. The Widows' Creek type control valve was selected as reference. CAMA is expected to be commercially utilized to accurately design and operate the turbine system for fossil as well as nuclear power