超声速弹丸高空流场数值模拟与稀薄气体效应研究

摘要

利用直角坐标网格技术研究高超声速稀薄气体流动的DSMC模拟方法，编制了高空弹丸外流场数值模拟通用计算程序，将本方法的计算结果与有关文献中公布的理论模型数据进行了对比，验证本方法的正确性。模拟了稀薄流下不同海拔高度尖拱型弹头和其他外形弹头的在超声速来流中的流场，并推广至不同外形弹头气动受力情况的计算，研究其稀薄效应。分析比较发现了随着海拔高度的升高，稀薄效应使弹丸的激波层厚度增加，外部流场压缩性减弱，表面的热流密度有所降低。相比于尖拱型弹头，钝头弹丸在驻点处所受的压力较小，尾部较强，符合高超声速飞行器钝头弹体的受力规律。%A general computer program for numerical simulation of supersonic warhead in the high flow field by using DSMC simulation method with the Cartesian coordinate ’s grid technique researching of hypersonic gas flow was worked out.To prove the validity of this method,the article made a contrast of the results with the data of theoretical model released related literature.Then,rarefied flow was simulated and calculated under different altitude,about the point arch warhead and other kinds of warheads in supersonic flow,the objective extending to the aerodynamic force calculation of different warhead shapes was used to study the effect of rarefied atmosphere.Analysis shows that with the elevation of altitude,the thickness of shock layer of the warhead increases because of rarefaction effect,and the compressibility of external flow field recedes,and the heat flux on the surface of warhead decreases.Compared with the pointed arch warhead,the pressure of blunt projectile is small in the stagnation point and is strong in the rear,which is in accord with the force law of blunt body of hypersonic aircrafts.