过渡流区N-S/DSMC耦合计算研究

Research on CFD/DSMC hybrid numerical method in rarefied flows

在已有CFD和DSMC方法程序研究基础上,采用MPC耦合处理原理,发展适于流场分区信息交换的亚松弛技术,建立了N-S/DSMC耦合算法。通过对近连续过渡流区不同Kn数条件下钝锥绕流计算与低密度风洞试验结果比较分析,一方面证明了本文所建立的N-S/DSMC耦合计算模型和方法在低Kn数过渡流区的有效性,另一方面剖析了N-S/DSMC耦合计算误差,可望发展一个工程适用的近连续过渡流区高超声速飞行器气动特性预测分析工具。

Based on the study on programming of CFD and DSMC method, a CFD/DSMC hybrid method is established employing MPC principle. A sub-relax technique is adopted to deal with information exchange between CFD and DSMC. Flows around a blunt cone at variation Kn numbers are simulated by the CFD/ DSMC hybrid method. Comparison of the calculation results with the related low density wind tunnel test data shows a coincidence between them, which means that the hybrid method is an effective method in lower Kn numbers. The errors are analyzed of the hybrid method. This work is hopeful of developing a useful tool to predict aerodynamic characteristics of hypersonic vehicles in transitional flows.