自由分子流区气体外掠平板/圆柱体流动与传热预测
|
摘要
针对自由分子流区稀薄气体外掠物体流动与传热问题,基于气体分子动理论方法和相对坐标系思想,推导了预测大气外掠平板和圆柱体传热与流动的无量纲表达式,讨论了雷诺数、马赫数和克努森数对阻力与传热性能的影响。结果表明:在马赫数一定时,随着克努森数不断增加,稀薄气体外掠物体换热能力逐渐减弱;在克努森数一定时,低马赫数(Ma<0.1)对传热性能影响不大,但高马赫数(Ma>0.1)对传热性能影响显著;随着马赫数增加,流动阻力先急剧下降,当到达超声速时逐渐变缓。该研究结果可为飞行器在自由分子流区流动与传热性能预测方面提供理论依据和技术支持。
Aiming at the problem of flow and heat transfer of rarefied gas over objects in free molecular flow regime and based on gas molecular kinetic theory and relative coordinate system, dimensionless expressions for predicting the flow and heat transfer performance of gas over flat plates and cylinders are deduced, and the effects of Reynolds number, Mach number and Knudsen number on flow resistance and heat transfer performance are discussed. This research shows that the heat transfer ability gradually weakens with the increasing of Knudsen number when the Mach number is constant; when the Knudsen number is constant, low Mach number(Ma<0.1) has little effect on the heat transfer performance, but high Mach number(Ma>0.1) has significant effect on the heat transfer performance. As the Mach number increases, the flow resistance drops sharply first, and then gradually slows down while reaching the supersonic speed. This study can provide theoretical basis and technical support for the prediction of the flow and heat transfer performance of rarefied gas over aircraft in the free molecular flow regime.
Aiming at the problem of flow and heat transfer of rarefied gas over objects in free molecular flow regime and based on gas molecular kinetic theory and relative coordinate system, dimensionless expressions for predicting the flow and heat transfer performance of gas over flat plates and cylinders are deduced, and the effects of Reynolds number, Mach number and Knudsen number on flow resistance and heat transfer performance are discussed. This research shows that the heat transfer ability gradually weakens with the increasing of Knudsen number when the Mach number is constant; when the Knudsen number is constant, low Mach number(Ma<0.1) has little effect on the heat transfer performance, but high Mach number(Ma>0.1) has significant effect on the heat transfer performance. As the Mach number increases, the flow resistance drops sharply first, and then gradually slows down while reaching the supersonic speed. This study can provide theoretical basis and technical support for the prediction of the flow and heat transfer performance of rarefied gas over aircraft in the free molecular flow regime.
引文
[1]张建华,贺碧蛟,蔡国飙,等.卫星姿控发动机喷管羽流撞击效应试验[J].空气动力学学报,2007,25(2):250-255.ZHANG Jianhua,HE Bijiao,CAI Guobiao,el at.Experimental study on plum impingement effects of satellite attitude control thruster nozzle[J].Acta Aerodynamica Sinica,2007,25(2):250-255.
[2]XIE F S,LI Y Z,LIU Z,et al.A forced convection heat transfer correlation of rarefied gases cross-flowing over a circular cylinder[J].Experimental Thermal&Fluid Science,2016,80:327-336.
[3]谢福寿,厉彦忠,王鑫宝,等.低真空压力下横掠圆柱体强制对流传热特性的实验研究[J].西安交通大学学报,2017,51(3):43-61.XIE Fushou,LI Yanzhong,WANG Xinbao,et al.Experimental study on the forced convection heat transfer characteristics of air flow across a cylinder under low vacuum pressures[J].Journal of Xi’an Jiaotong University,2017,51(3):43-61.
[4]XIE F S,LI Y Z,WANG X B,et al.Numerical study on flow and heat transfer characteristics of low pressure gas in slip flow regime[J].International Journal of Thermal Sciences,2018,124:131-145.
[5]谢福寿,雷刚,邱一男,等.求解滑移流区外掠圆柱体气流流动与传热特性的数值模型[J].西安交通大学学报,2019,53(1):25-32.XIE Fushou,LEI Gang,QIU Yinan,et al.A numerical model for the flow and heat transfer characteristics of rarefied gas over a cylinder in slip flow regime[J].Journal of Xi’an Jiaotong University,2019,53(1):25-32.
[6]陈熙.动力论及其在传热与流动研究中的应用[M].北京:清华大学出版社,1996:77-185.
[7]沈青.稀薄气体动力学[M].北京:国防工业出版社,2003:141-160.
[8]SHEN C.Rarefied gas dynamics[M].New York,USA:Springer,2005:159-190.
[9]LOH W H T.Modern developments in gas dynamics[M].New York,USA:Plenum Press,1969:235-254.
[10]MOHAMED G H.The fluid mechanics of microdevices[J].Journal of Fluids Engineering,1999,121(5):5-33.
[11]TSIEN H S.Superaerodynamics,mechanics of rarefied gases[J].Journal of the Aeronautical Sciences,1946,13(12):653-664.
[12]OLVER F W,LOZIER D W,BOISVERT R F,et al.NIST handbook of mathematical functions[M].UK:Cambridge University Press,2010:217-261.
[2]XIE F S,LI Y Z,LIU Z,et al.A forced convection heat transfer correlation of rarefied gases cross-flowing over a circular cylinder[J].Experimental Thermal&Fluid Science,2016,80:327-336.
[3]谢福寿,厉彦忠,王鑫宝,等.低真空压力下横掠圆柱体强制对流传热特性的实验研究[J].西安交通大学学报,2017,51(3):43-61.XIE Fushou,LI Yanzhong,WANG Xinbao,et al.Experimental study on the forced convection heat transfer characteristics of air flow across a cylinder under low vacuum pressures[J].Journal of Xi’an Jiaotong University,2017,51(3):43-61.
[4]XIE F S,LI Y Z,WANG X B,et al.Numerical study on flow and heat transfer characteristics of low pressure gas in slip flow regime[J].International Journal of Thermal Sciences,2018,124:131-145.
[5]谢福寿,雷刚,邱一男,等.求解滑移流区外掠圆柱体气流流动与传热特性的数值模型[J].西安交通大学学报,2019,53(1):25-32.XIE Fushou,LEI Gang,QIU Yinan,et al.A numerical model for the flow and heat transfer characteristics of rarefied gas over a cylinder in slip flow regime[J].Journal of Xi’an Jiaotong University,2019,53(1):25-32.
[6]陈熙.动力论及其在传热与流动研究中的应用[M].北京:清华大学出版社,1996:77-185.
[7]沈青.稀薄气体动力学[M].北京:国防工业出版社,2003:141-160.
[8]SHEN C.Rarefied gas dynamics[M].New York,USA:Springer,2005:159-190.
[9]LOH W H T.Modern developments in gas dynamics[M].New York,USA:Plenum Press,1969:235-254.
[10]MOHAMED G H.The fluid mechanics of microdevices[J].Journal of Fluids Engineering,1999,121(5):5-33.
[11]TSIEN H S.Superaerodynamics,mechanics of rarefied gases[J].Journal of the Aeronautical Sciences,1946,13(12):653-664.
[12]OLVER F W,LOZIER D W,BOISVERT R F,et al.NIST handbook of mathematical functions[M].UK:Cambridge University Press,2010:217-261.