高超声速层流尾迹的数值模拟

NUMERICAL SIMULATION OF HYPERSONIC LAMINAR WAKE FLOW

本文利用无波动、无自由参数、耗散的差分格式(NND格式),通过求解NS方程,数值模拟了高超声速层流尾迹的流动,清晰地给出了主激波、拐角膨胀波、迹激波及自由剪切层,所得流场物理量的分布与实验结果甚为一致。计算发现了底部迴流区由起始向定常的发展中,在瞬时流线图上经历了极限环形成、胀大、缩小、再胀大最后消失的演变过程。

The hypersonic laminar wake flow behind spherically blunted cone is studied by solving Navier-Stokes equations with NND schemes (Non oscillatory, containing no free parameters and dissipative scheme). The bow shock, corner expansion fan, wake shock and free layer in the wake region are captured successfully. The calculated pressure, temperature and velocity distributions along the wake centerline agree with experimental date satisfactorily. Especially, the history of vortex in the recirculation region started impulsively from rest is explored. It is found that the consequences of development of vortex are related to the variation of limit cycle of transient streamlines.