标模外形化学非平衡流场数值模拟

利用三维并行计算代码求解Navier-Stokes方程,数值模拟标模(ELECTRE)化学非平衡绕流,研究真实气体效应对标模气动热特性的影响,反应模型为Dunn和Kang的7组元7反应化学动力学模型.利用典型弹道点的飞行试验数据验证化学非平衡流计算程序的可靠性.在此基础上,研究不同壁面催化条件下攻角和高度变化对热流的影响.计算表明:真实气体效应主要发生在物面附近很薄的激波层内,并使激波脱体距离减小;完全催化壁驻点热流值高于非催化壁热流值;随着攻角增大,热流分布差异明显,而且攻角越大时,物面电子数密度越小;飞行高度越高,O₂和N₂离解程度越低,驻点热流越低.

Numerical Simulation on Chemical Nonequilibrium Flowfield in Standard Model

A three-dimensional computational fluid dynamics algorithm is developed to study chemical nonequilibrium flowfield in a standard model, ELECTRE, for which flight data exits. A finite rate chemistry model based on Dunn and Kang's model is implemented. An extensive investigation on catalysis modeling relevance simulations with non-catalytic wall conditions as well as with full catalytic boundary conditions is made. The method developed is used to compute detailed flow features of hypersonic flow around forebody of a sphere-cone vehicle under different attack angles and altitudes. It is shown that reacting gas numerical results are consistent with flight data. It shows that real gas effects are prominent in thin shock wave layers closing to the wall surface. It makes outstanding distance of shock wave short. Heat flux under full catalytic wall boundary condition is higher than that under non-catalytic condition. The greater the attack angle,the more obvious this variance and the less electron number density on the wall. The higher the flight altitude,the lower dissociation of oxygen and nitrogen,and the lower heat flux on stagnation point.