热端管长度对涡流管流场影响的数值模拟研究
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摘要
以理想CO_2气体为工质,采用Standard k-ε湍流模型,对涡流管能量分离效应进行数值模拟,分析了管内流体流场的分布以及内旋流与外旋流分离界面的分布。在此基础上,探究了进口温度为298.15 K、进口压力为6.5 MPa、冷流率为0.1时,热端管长度对涡流管内流场分布以及能量分离性能的影响。模拟结果表明:热端管长度在100～200 mm范围内变化时,随着热端管长度的增大,轴向上:轴向速度逐渐增大,切向速度逐渐减小、径向上:轴向速度会出现运动方向相反的情况,切向速度先增大后减小,制冷温度效应呈现先增大后减小的趋势。
The flow-field in a vortex tube,with ideal CO_2 gas medium,was mathematically formulated with a standard k-ε turbulence model and numerically simulated.The influence of the hot end tube length on the flow-field distributions and energy separation was investigated under the conditions:298.15 K and 6.5 MPa at the inlet,and a cold flow-rate of 0.1.The simulated results show that the hot end tube length has a major impact.To be specific,as the length increases in 100～200 mm range,the axial velocity increases,accompanied by a decreasing tangential velocity;the interface,separating the distributions of internal/external swirling flows,changes in an increase-decrease manner;both the refrigeration and heating effects change in an increase-decrease mode.The optimized refrigeration(ΔT_c=21.12 K) can be obtained with an aspect ratio of 25,that is,a length of 125 mm.
The flow-field in a vortex tube,with ideal CO_2 gas medium,was mathematically formulated with a standard k-ε turbulence model and numerically simulated.The influence of the hot end tube length on the flow-field distributions and energy separation was investigated under the conditions:298.15 K and 6.5 MPa at the inlet,and a cold flow-rate of 0.1.The simulated results show that the hot end tube length has a major impact.To be specific,as the length increases in 100～200 mm range,the axial velocity increases,accompanied by a decreasing tangential velocity;the interface,separating the distributions of internal/external swirling flows,changes in an increase-decrease manner;both the refrigeration and heating effects change in an increase-decrease mode.The optimized refrigeration(ΔT_c=21.12 K) can be obtained with an aspect ratio of 25,that is,a length of 125 mm.
引文
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[13] Dutta T,Sinhamahapatra K P,Bandyopdhyay S S. Comparison of Different Turbulence Models in Predicting the Temperature Separation in a Ranque-Hilsch Vortex Tube Tube[J]. International Journal of Refrigeration,2012,33:783-792
[14] Aljuwayhel N F,Nellis G F,Klein S A. Parametric and Internal Study of the Vortex Tube Using a CFD Model[J]. International Journal of Refrigeration,2005,28:442-450
[15]周少伟,姜任秋,宋福元,等.涡流管内流动与传热数值模拟[J].化工学报,2006,(07):1548-1552
[16]李龙,何望云,李言,等.小管径涡流管三维数值模拟及热力学过程分析[J].机械科学与技术,2016,35(05):734-739
[17]曹勇.小流量涡流管特性的理论与实验研究[D].杭州:浙江大学,2003
[2] Thomas T Bruno. Simple,Inexpensive Apparatus for Sample Concentration[J]. Journal of Chemical Education,1992,69(10):837-838
[3] Brock Hajdik,Manfred Lorey. Vortex Tube can Increase Liquid Hydrocarbon Recovery at Plant Inlet[J]. Oil&GAS Journal,1997,95(36):76-83
[4] Choi H Z,Lee S W,Jeong H D. A Comparison of Thecooling Effects of Compressed Cold Air and Coolantfor Cylindrical Grinding with a CBN Wheel[J]. Journal of Materials Processing Technology,2001,11:265-268
[5] Krasovitaski R,Tunekl L. Vortex Heat Exchanger:Design,Experiment and Mathematical Model[J]. Journal of Enhanced Heat Transfer,2001,8(1):15-22
[6] Westley R. Optimum Design of a Vortex Tube for Achieving Larger Temperature Drop Ratios[J].Cranfield College Note30,College of Aeronautics,1955
[7] Heishichiro Takahama. Studies on Vortex Tube[J]. Bulletin of JSME,1965,8(31):433-440
[8] Saidi M H,Valipour M S. Experimental Modeling of Vortex Tube Refrigerator[J]. Applied Thermal Engineering,2003,15(23):1971-1980
[9]计玉帮,吴玉庭,丁雨,等.涡流管结构参数对其性能的影响[J].航空动力学报,2006,(01):88-93
[10]周少伟.涡流管能量分离效应的理论与试研[D].哈尔滨:哈尔滨工程大学,2007
[11] Skye H M,Nellis G F,Klein S A. Comparison of CFD Analysis to Empirical Data in a Commercial Vortex Tube[J]. International Journal of Refrigeration,2006,29(1):71-80
[12] Thakare H R,Parekh A D. CFD Analysis of Energy Separation of Vortex Tube Employing Differentgases,Turbulence Models and Discretisationschemes[J]. International Journal of Heat and Mass Transfer,2014,78:360-370
[13] Dutta T,Sinhamahapatra K P,Bandyopdhyay S S. Comparison of Different Turbulence Models in Predicting the Temperature Separation in a Ranque-Hilsch Vortex Tube Tube[J]. International Journal of Refrigeration,2012,33:783-792
[14] Aljuwayhel N F,Nellis G F,Klein S A. Parametric and Internal Study of the Vortex Tube Using a CFD Model[J]. International Journal of Refrigeration,2005,28:442-450
[15]周少伟,姜任秋,宋福元,等.涡流管内流动与传热数值模拟[J].化工学报,2006,(07):1548-1552
[16]李龙,何望云,李言,等.小管径涡流管三维数值模拟及热力学过程分析[J].机械科学与技术,2016,35(05):734-739
[17]曹勇.小流量涡流管特性的理论与实验研究[D].杭州:浙江大学,2003