基于工程转捩模型的高超声速进气道特性

为研究高超声速进气道的性能参数随飞行高度、来流湍流度及来流马赫数的变化规律，并考察其压缩面上的边界层转捩现象对进气道性能的影响，采用本课题组程序平台HGFS所发展的γ-Re_θ转捩模型进行了一系列的数值模拟工作，并对相应的流动现象和机理进行分析。首先，利用进气道压缩面的简化模型对γ-Re_θ转捩模型经验关联公式的高超声速改进方法进行了验证；其次，以某型等熵压缩面的高超声速进气道为对象，研究了飞行高度、来流马赫数对边界层转捩位置等多个参数的影响。结果表明：随着飞行高度的增加，压缩面上边界层转捩位置延后，进气道总压恢复系数下降；与地表情况相比，在设计飞行高度转捩位置延后了约0.525 m，边界层厚度增加了约73%，总压恢复系数下降了约3.2%；来流湍流度变化0.5%量级可导致转捩位置移动0.2 m左右，但来流湍流度对总压恢复系数的影响则很小。

Hypersonic air inlet performance based on engineering transition model

In order to study the variation of the performance parameters of a hypersonic air inlet with the flight height, free stream turbulence intensity and free stream Mach number, and the influence of the boundary layer transition on the compression surface on air inlet performance, a series of numerical simulations were conducted by using the γ-Re_θ transition model developed in a in-house HGFS and the flow phenomena and mechanisms were analyzed. Firstly, the improved γ-Re_θ transition model implemented in the HGFS code was verified using a simplified model of an air inlet compression surface. Secondly, a hypersonic air inlet with isentropic compression surface was studied the effect of flight height and Mach number on parameters such as the transition location. Main conclusions are as follows:with the increase of the flight height, transition location of the boundary layer moves downstream on the compression surface, and the total pressure recovery coefficient decreases. Compared with the ground surface state, at the design flight height, the transition location moves downstream for about 0.525 m, the boundary layer thickness increases by about 73%, and the total pressure recovery coefficient decreases by 3.2%. About 0.5% magnitude change of the inflow turbulence intensity will contribute to 0.2 m movement of the transition location. However, the influence of turbulence intensity on the total pressure recovery coefficient is quite small.