一种双斜切双压缩面进气道地面流态的数值模拟研究

 采用基于 MUSCL插值的 Roe格式三维 N-S方程数值求解程序对地面状态下双斜切双压缩面进气道内外流场进行了数值分析,得到了其流动图谱,分析了其流场特征。计算中考虑了机身和边条翼的影响,计算结果表明 :1在进气道进口段外壁和下壁内交角处出现了较大的贴角分离包,分离导致了进气道出口较大总压畸变的产生。 2进气道横截面二次流动在进口段表现为一反向旋转的对涡,对涡中顺时针的旋涡较强,控制了进气道的外上角,逆时针的较弱,控制了进气道的内下角;在出口截面表现为较强的顺时针旋向的整体旋流。 3由于顺时针旋流的影响,进气道横截面上的总压高压区位置由进口段的内上角顺时针旋转到了出口截面的外上部,而由分离引起的总压低压区则由进口段的外下角顺时针旋转到了出口的内下部。将计算结果与实验结果进行了比较,验证了所采用的数值模拟方法的可靠性。

NUMERICAL SIMULATION OF A DUAL-SWEPT/DUAL-RAMP INLETUNDER GROUND RUNNING

Combined with the LU SGS implicit scheme and MUSCL interpolation method, Roe's approximate Riemann scheme is applied to develop a code for 3 D compressible Navier Stokes equations. With this code the flow field structure and aerodynamic performance of a dual swept/dual ramp inlet under ground running are investigated, and the effect of the fuselage and LEX is considered in this calculation. The results calculated show that: (a) Large scale separation occurs at the fore part of the bottom outside corner, which is the cause of large total pressure distortion at the exit section. (b) The secondary flow at the cross section in the fore part of the inlet behaves as two counter rotating vortices: the clockwise one is stronger, governing the up outside corner, while the anti clockwise one is weaker, governing the bottom inside corner; at the outlet section, the secondary flow behaves as a bulk swirl. (c) As a result of the swirling flow, the high and low total pressure zones are rotated markedly. Furthermore, comparisons of the CFD results and experiment results are made to validate the reliability of the code used in this paper.