高超声速非平衡流区域识别及网格自适应重构DSMC方法  

Hypersonic nonequilibrium flow region identification and adaptive grid reconfiguration DSMC method

作　　者：李子玮 王学德[1] LI Ziwei;WANG Xuede(School of Energy and Power Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学能源与动力工程学院,南京210094

出　　处：《航空动力学报》2025年第2期182-189,共8页Journal of Aerospace Power

摘　　要：采用分子动力学理论导出系统熵与熵产率的计算公式,识别高超声速稀薄流非平衡区域。根据熵产与非平衡现象的基本关系,确定了衡量气体非平衡态的判断方法。由于熵产率参数存在局限性,提出了一种熵产克努森数(Knudsen number)作为气体非平衡态衡量参数,与局部克努森数相结合作为非平衡态判据。基于两种非平衡判据相结合的策略,发展了一套高超声速流场非平衡区域识别与网格自适应重构的DSMC(direct simulation Monte Carlo)计算方法。对典型非平衡流场进行模拟,数值结果表明:所提出的识别参数能精准识别全流场中的非平衡效应,识别率达到了99%以上。在此基础上重构非平衡区域网格,计算得到的流场宏观量相对误差小于3%,壁面气动参数相对误差小于5%,证明了自适应重构方法的有效性。By using the molecular dynamics theory,the calculation formulas for system entropy and entropy production rate were derived to identify non-equilibrium regions in hypersonic rarefied flows.A method for measuring the non-equilibrium state of gases was determined based on the fundamental relationship between entropy production and non-equilibrium phenomena.Due to the limitations of entropy production rate parameters,a gas non-equilibrium measure parameter called the entropy production Knudsen number was proposed,which was combined with the local Knudsen number as a criterion for non-equilibrium states.By integrating two non-equilibrium criteria,a direct simulation Monte Carlo(DSMC)computational method was developed for identifying non-equilibrium regions and performing grid adaptive reconstruction in hypersonic flow fields.Typical non-equilibrium flow fields were simulated,the results showed that the proposed identification parameters can accurately identify nonequilibrium effects throughout the flow field,with an identification rate of over 99%.On the basis of this strategy,the grid in the non-equilibrium region was reconstructed,and the relative errors of the macroscopic flow field quantities were less than 3%,while the relative errors of wall aerodynamic parameters were less than 5%,which demonstrated the effectiveness of adaptive reconstruction method.

关 键 词：高超声速 非平衡流动 DSMC方法 熵产率 自适应网格 

分 类 号：V448.2[航空宇航科学与技术—飞行器设计]