侧板边界层对正激波/边界层干扰特性影响的数值模拟研究

Numerical Study of Effects of Side-Wall Boundary Layer on Normal Shock Wave/Boundary Layer Interactions

关键词:  正激波/边界层干扰  结尾激波  侧板边界层  三维效应  角区分离

Key words:  Normal shock wave/boundary layer interaction  Terminal shock  Side-wall boundary layer  3D effect  Corner separation

摘要:

为了研究外压式进气道处于临界工况时结尾正激波同时与压缩面和侧板上边界层的相互干扰，专门设计了三组具有不同前伸长度侧板的简化构型作为研究对象，利用数值模拟手段评估了侧板边界层厚度对正激波/边界层干扰特性的影响。仿真结果表明，当没有侧板边界层参与干扰时流动呈现较好的准二维特性，但当侧板边界层参与干扰后将形成较强的角区干扰结构，该角区三维干扰结构与对称面上的准二维干扰结构存在此消彼长的关系。此外，波系的空间形态也将由“准二维λ波”结构变为“双λ波+角区压缩波”结构，波系形态的改变则进一步导致壁面回流区分布以及摩擦力线拓扑结构变得更加复杂。

Abstract:

In order to investigate interactions between terminal shock wave of an external-compression inlet and boundary layers on the ramp and side-wall under critical condition， three simplified configurations with different side-wall lengths are specially designed to evaluate the effects of side-wall boundary layer thickness on normal shock wave/boundary layer interactions numerically. Simulation results show that the flowfield is quasi two-dimensional when there is no side-wall boundary involved in the interaction. However corner interaction structure is formed when side-wall boundary is involved in the interaction， and the increase of three-dimensional interaction structure in the corner leads to the suppression of quasi two-dimensional interaction structure in the symmetry plane. Besides， shock pattern transforms from quasi-two dimensional λ shock pattern into ‘double λ shock + corner compression waves’， which further makes reversal regions and topology of wall shear stress on the walls more complicated.