不同边界层厚度下高马赫数进气道自起动过程研究

Self-Starting Process of High Mach Number Inlet with Different Boundary Layer Thicknesses

关键词:  高马赫数进气道  边界层厚度  边界层动量损失厚度  主分离包高度  无量纲压升

Key words:  High Mach number inlets  Boundary layer thickness  Boundary layer momentum deficit thickness  Primary separation bubble height  Dimensionless pressure rise

摘要:

为了探寻入口边界层厚度变化对高马赫数进气道自起动性能的影响，对简化的二元高马赫数进气道的加速自起动过程进行数值仿真研究，分析了边界层厚度对自起动过程中流场波系结构变化和自起动性能的影响机制，获得了不同边界层厚度下的进气道自起动性能及主分离包高度的变化规律。结果表明：随着边界层相对厚度从0.05增加至0.3，进气道的自起动马赫数一开始保持不变，然后快速增大；相同主流条件下，不起动流场跨越主分离包无量纲压升和主分离包高度随边界层相对厚度的增大均变小；边界层动量损失厚度和跨越主分离包无量纲压升对进气道起动性能影响重大。

Abstract:

In order to explore the effect of inlet boundary layer thickness on self-starting performance of high Mach number inlets, numerical simulation and theoretical analysis were carried out. The self-starting performance of the inlet and the height of the primary separation bubble with different boundary layer thicknesses were obtained. The influencing mechanism on flow field structure and self-starting performance were also analyzed. The results indicated that: As the relative thickness of the boundary layer increases from 0.05 to 0.3, the self-starting Mach number of the inlet remains unchanged at first, and then increases rapidly. Under the same mainstream conditions, dimensionless pressure rise across the primary separation bubble and the primary separation bubble height both decrease with the increase of the boundary layer thickness. The boundary layer momentum deficit thickness and the dimensionless pressure rise determine the self-starting performance of high Mach number inlets.