Xiao Hong, Shang Yuhe, Wu Di
School of Power and Energy, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
ScientificWorldJournal. 2014 Jan 30;2014:732765. doi: 10.1155/2014/732765. eCollection 2014.
Direct simulation Monte Carlo (DSMC) of shock interaction in hypersonic low density flow is developed. Three collision molecular models, including hard sphere (HS), variable hard sphere (VHS), and variable soft sphere (VSS), are employed in the DSMC study. The simulations of double-cone and Edney's type IV hypersonic shock interactions in low density flow are performed. Comparisons between DSMC and experimental data are conducted. Investigation of the double-cone hypersonic flow shows that three collision molecular models can predict the trend of pressure coefficient and the Stanton number. HS model shows the best agreement between DSMC simulation and experiment among three collision molecular models. Also, it shows that the agreement between DSMC and experiment is generally good for HS and VHS models in Edney's type IV shock interaction. However, it fails in the VSS model. Both double-cone and Edney's type IV shock interaction simulations show that the DSMC errors depend on the Knudsen number and the models employed for intermolecular interaction. With the increase in the Knudsen number, the DSMC error is decreased. The error is the smallest in HS compared with those in the VHS and VSS models. When the Knudsen number is in the level of 10(-4), the DSMC errors, for pressure coefficient, the Stanton number, and the scale of interaction region, are controlled within 10%.
开展了高超声速低密度流中激波相互作用的直接模拟蒙特卡洛（DSMC）研究。DSMC研究中采用了三种碰撞分子模型，包括硬球（HS）、可变硬球（VHS）和可变软球（VSS）。进行了低密度流中双锥和埃德尼IV型高超声速激波相互作用的模拟。开展了DSMC与实验数据的对比。对双锥高超声速流的研究表明，三种碰撞分子模型能够预测压力系数和斯坦顿数的变化趋势。在三种碰撞分子模型中，HS模型的DSMC模拟结果与实验结果吻合度最佳。此外，研究表明，在埃德尼IV型激波相互作用中，DSMC与实验结果在HS和VHS模型下总体吻合良好。然而，VSS模型的结果并不理想。双锥和埃德尼IV型激波相互作用模拟均表明，DSMC误差取决于克努森数和用于分子间相互作用的模型。随着克努森数的增加，DSMC误差减小。与VHS和VSS模型相比，HS模型的误差最小。当克努森数处于10^(-4)水平时，压力系数、斯坦顿数和相互作用区域尺度的DSMC误差控制在10%以内。
