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A swirling jet from a nozzle with tangential inlets and its characteristics in breaking-up rocks 被引量:1
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作者 Yang Yongyin Zou Deyong +2 位作者 Sun Weiliang Li Xinhui Niu Sicheng 《Petroleum Science》 SCIE CAS CSCD 2012年第1期53-58,共6页
In order to apply a swirling jet to a PDC drill bit, the nozzle performance influenced by nozzle inlet geometric parameters and rock breaking tests under submerged conditions were studied. Numerical simulation was use... In order to apply a swirling jet to a PDC drill bit, the nozzle performance influenced by nozzle inlet geometric parameters and rock breaking tests under submerged conditions were studied. Numerical simulation was used to study the influence of the nozzle structure on the swirling intensity and nozzle discharge coefficient. Simulation results indicate that spreading angle of the swirling jet is greater than that of" the non-swirling jet, and the swirling intensity of the jet is strongly influenced by the length of the nozzle body but weakly by the number of tangential inlets. Rock breaking tests were conducted to evaluate the performance of the swirling jet. It is found that the swirling jet shows a lower threshold pressure to break the rock samples and could break rock more efficiently compared with the non-swirling jet. 展开更多
关键词 NOZZLE JET swirling intensity discharge coefficient simulation rock breaking tests
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Numerical investigation of the velocity field and separation efficiency of deoiling hydrocyclones 被引量:4
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作者 MADDAHIAN Reza ASADI Mohammad FARHANIEH Bijan 《Petroleum Science》 SCIE CAS CSCD 2012年第4期511-520,共10页
Three-dimensional simulation of a multiphase flow is performed using the EulerianEulerian finite volume method in order to evaluate the separation efficiency and velocity field of deoiling hydrocyclones.The solution i... Three-dimensional simulation of a multiphase flow is performed using the EulerianEulerian finite volume method in order to evaluate the separation efficiency and velocity field of deoiling hydrocyclones.The solution is developed using a mass conservation-based algorithm(MCBA) with collocated grid arrangement.The mixture approach of the Reynolds stress model is also employed in order to capture features of turbulent multiphase swirling flow.The velocity field and separation efficiency of two different configurations of deoiling hydrocyclones are compared with available experimental data.The comparison shows that the separation efficiency can be predicted with high accuracy using computational fluid dynamics.The velocity fields are also in good agreement with available experimental velocity measurements.Special attention is drawn to swirl intensity in deoiling hydrocyclones and it is shown that the differences in velocity and volume fraction fields of different configurations are related to swirl distribution. 展开更多
关键词 Deoiling hydrocyclone numerical simulation Eulerian-Eulerian approach swirl intensity
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Turbulent flow in converging nozzles,part one:boundary layer solution
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作者 R.MADDAHIAN B.FARHANIEH B.FIROOZABADI 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第5期645-662,共18页
The boundary layer integral method is used to investigate the development of the turbulent swirling flow at the entrance region of a conical nozzle. The governing equations in the spherical coordinate system are simpl... The boundary layer integral method is used to investigate the development of the turbulent swirling flow at the entrance region of a conical nozzle. The governing equations in the spherical coordinate system are simplified with the boundary layer as- sumptions and integrated through the boundary layer. The resulting sets of differential equations are then solved by the fourth-order Adams predictor-corrector method. The free vortex and uniform velocity profiles are applied for the tangential and axial velocities at the inlet region, respectively. Due to the lack of experimental data for swirling flows in converging nozzles, the developed model is validated against the numerical simulations. The results of numerical simulations demonstrate the capability of the analytical model in predicting boundary layer parameters such as the boundary layer growth, the shear rate, the boundary layer thickness, and the swirl intensity decay rate for different cone angles. The proposed method introduces a simple and robust procedure to investigate the boundary layer parameters inside the converging geometries. 展开更多
关键词 swirling flow converging nozzle swirl intensity decay rate boundary layer integral method analytical solution
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The Influence of Fuel-Air Swirl Intensity on Flame Structures of Syngas Swirl-Stabilized Diffusion Flame 被引量:4
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作者 Weiwei Shao Yan Xiong +3 位作者 Kejin Mu Zhedian Zhang Yue Wang Yunhan Xiao 《Journal of Thermal Science》 SCIE EI CAS CSCD 2010年第3期276-283,共8页
Flame structures of a syngas swirl-stabilized diffusion flame in a model combustor were measured using the OH-PLIF method under different fuel and air swirl intensity.The flame operated under atmospheric pressure with... Flame structures of a syngas swirl-stabilized diffusion flame in a model combustor were measured using the OH-PLIF method under different fuel and air swirl intensity.The flame operated under atmospheric pressure with air and a typical low heating-value syngas with a composition of 28.5% CO,22.5% H2 and 49% N2 at a thermal power of 34 kW.Results indicate that increasing the air swirl intensity with the same fuel,swirl intensity flame structures showed little difference except a small reduction of flame length;but also,with the same air swirl intensity,fuel swirl intensity showed great influence on flame shape,length and reaction zone distribution.Therefore,compared with air swirl intensity,fuel swirl intensity appeared a key effect on the flame structure for the model combustor.Instantaneous OH-PLIF images showed that three distinct typical structures with an obvious difference of reaction zone distribution were found at low swirl intensity,while a much compacter flame structure with a single,stable and uniform reaction zone distribution was found at large fuel-air swirl intensity.It means that larger swirl intensity leads to efficient,stable combustion of the syngas diffusion flame. 展开更多
关键词 Diffusion Flame Swirl intensity Flame Structure OH-PLIF
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Experimental Investigations of the Flow Field Structure and Interactions between Sectors of a Double-Swirl Low-Emission Combustor:Effects of Main Stage Swirl Intensity and Venturi Angle 被引量:3
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作者 FAN Xiongjie XU Gang +3 位作者 LIU Cunxi ZHANG Chi WANG Jianchen LIN Yuzhen 《Journal of Thermal Science》 SCIE EI CAS CSCD 2020年第3期813-819,共7页
Effect of venturi angle and main stage swirl intensity on flow field and interactions were investigated using PIV.The results showed the difference between the side sector and the middle sector was caused by interacti... Effect of venturi angle and main stage swirl intensity on flow field and interactions were investigated using PIV.The results showed the difference between the side sector and the middle sector was caused by interactions.The interactions were stronger with the rise of the main stage swirl intensity.When the swirl intensity was 0.7 and 0.9,there was little difference of the width of the recirculation zone.But the flow field had a great difference when the swirl intensity was 0.5 and 0.7,which means that when the swirl intensity was small,the swirl intensity had a great influence on the flow field.Venturi angle had a great influence on the flow field structure and interactions when the venturi angle was big,such as 90°.The venturi angle just had a small influence on the width of the recirculation zone when the venturi angle was relatively small,such as 28°and 52°.The velocity of the center plane between two sectors(plane 3)was small.There was a recirculation zone at upstream of the center plane between two sectors(plane 3)when the swirl intensity was 0.7 and 0.9,whereas not one when the swirl intensity was 0.5.The above was induced by interactions.In addition,the velocity of plane 1,plane 3,and plane 5 when the venturi angle was 52°was smaller than that of 28°and 90°. 展开更多
关键词 COMBUSTOR recirculation zone PIV swirl intensity venturi angle
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The influence of inlet swirl intensity and hot-streak on aerodynamics and thermal characteristics of a high pressure turbine vane 被引量:2
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作者 Zakaria MANSOURI Riyadh BELAMADI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2021年第11期66-78,共13页
In modern gas turbines,the High Pressure Turbine(HPT)is exposed to an extreme thermal environment due to the burned gases leaving the combustor.The burned gases are characterized by flow and temperature distortions th... In modern gas turbines,the High Pressure Turbine(HPT)is exposed to an extreme thermal environment due to the burned gases leaving the combustor.The burned gases are characterized by flow and temperature distortions that effect the aerodynamics and heat transfer of the turbine.The purpose of this paper is to investigate numerically the effect of the intensity of the swirling flow combined with the temperature non-uniformity‘‘Hot-Streak"(H-S)on the aerothermal performances of a HPT Nozzle Guide Vane(NGV).The investigations are conducted on the solid untwisted NGV annular cascade developed in NASA Lewis Research Center.Four swirl intensities(|S_(n)|=0,0.1,0.25 and 0.5),two swirl orientations(positive and negative)and two hot-streaks(rounded and radial)at the NGV inlet are considered.The simulations are done by solving the Reynolds Averaged Navier-Stokes(RANS)equations using ANSYS-CFX software.The results show that the H-S with swirl undergoes twisting following the orientation of the swirl.The H-S twist is aggressive under positive swirl compared to the negative swirl case.The inlet swirl generates a new secondary flow structure,so called Swirl Vortex(SV),which induces more aerodynamic losses.The aerodynamic efficiency under negative swirl found to be higher than that under positive swirl.The maximum temperature on the vane surface is controlled by the radial transport of the SV towards the endwalls. 展开更多
关键词 AERODYNAMICS Heat transfer Hot-Streak HP turbine NGV Swirl intensity
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Numerical study of coarse coal particle breakage in pneumatic conveying 被引量:7
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作者 Jiawei Zhou Yu Liu +2 位作者 Changlong Du Songyong Liu Jianping Li 《Particuology》 SCIE EI CAS CSCD 2018年第3期204-214,共11页
Pneumatic conveying of coarse coal particles with various pipeline configurations and swirling intensities was investigated using a coupled computational fluid dynamics and discrete element method. A particle cluster ... Pneumatic conveying of coarse coal particles with various pipeline configurations and swirling intensities was investigated using a coupled computational fluid dynamics and discrete element method. A particle cluster agglomerated by the parallel-bond method was modeled to analyze the breakage of coarse coal particles. The numerical parameters, simulation conditions, and simulation results were experimentally validated. On analyzing total energy variation in the agglomerate during the breakage process, the results showed that downward fluctuation of the total particle energy was correlated with particle and wall col- lisions, and particle breakage showed a positive correlation with the energy difference. The correlation between the total energy variation of a particle cluster and particle breakage was also analyzed. Parti- cle integrity presented a fluctuating upward trend with pipe bend radius and increased with swirling number for most bend radii. The degree of particle breakage differed with pipeline bending direction and swirling intensity: in a horizontal bend, the bend radius and swirling intensity dominated the total energy variations: these effects were not observed in a vertical bend. The total energy of the particle cluster exiting a bend was generally positively correlated with the bend radius for all conditions and was independent of bending direction. 展开更多
关键词 Computational fluid dynamics-discreteelement method Pneumatic conveying Pipeline configuration swirling intensity Coarse coal particle BREAKAGE
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