钝锥模型高焓流动的再压缩效应研究

在钝体高焓流动中,热化学非平衡效应使膨胀区壁面压力显著低于冻结流动,相关研究表明,再压缩效应可以消除上述差异. 为详细分析此问题,数值求解了Euler 方程,化学反应源项采用有限速率模型并考虑了5个组分,17 个基元反应. 结果表明,随着再压缩角的增大,热化学非平衡效应引起锥面压力先降后增非单调变化,这是由于再压缩流场中放热复合反应与吸热分解反应的强度变化决定的,其宏观表现为比热比的空间不均衡分布.

INVESTIGATION OF RECOMPRESSION EFFECTS ON THE HIGH-ENTHALPY SPHERE-CONIC MODEL FLOW

Thermo-chemical non-equilibrium effects may cause decrease in the surface pressure within the expansion region of a high-enthalpy blunt body flow as compared with a frozen flow. Research indicates that a recompression structure appended to the blunt body can eliminate the aforementioned difference. In the present study, a multi-component reactive Euler solver was applied to simulate the hypervelocity flow over a sphere-cone model. The numerical results show that thermo-chemical non-equilibrium induces a nonmonotonic variation to the conic surface pressure, i.e., it decreases first then increases as the recompression angle increases. The underlying mechanism for such a phenomenon is found to be the competing exothermal and endothermal reactions, which is macroscopically reflected by the inhomogeneity of the specific heat ratio in the recompression flowfield.