关键词: 高超声速, 粗糙壁, 气动热, 预测模型, 峰值热流

Abstract:

Micro ablation on the surface of new-type vehicles will lead to increased local heat flux on the wall surface. This study uses corrugated roughness with roughness height smaller than 600 μm to simulate micro ablative surfaces， and calculates the variation law of the peak heat flux on the wall surface with uniform corrugated roughness by directly solving the Navier-Stokes equation. It is found that the surface peak heat flux caused by roughness is inversely proportional to the 0.5 times of the flow position， the surface peak heat flux is proportional to the roughness height and decreases with increasing width， and is more influenced by the height than the width. Meanwhile， the influence results of the Mach number and wall temperature on the surface peak heat flux at the wall show that the relative surface peak heat flux increment is inversely proportional to both the Mach number and wall temperature. Further， based on the smooth flat plate heat flux theory solution， we provide the surface peak heat flux prediction formula. Detailed verification of the working conditions reveals that the formula can accurately predict the surface peak heat flux in the range of Mach number 4-10 and wall temperature 300-800 K with an error of no more than 8%. For other wall forms， such as elliptical and dispersive sine types， the formula can also produce an accurate prediction.

Key words: hypersonic, rough wall, aerodynamic heat, predictive model, peak heat flux