受限通道中三维激波与侧壁面作用的数值模拟研究

Numerical Investigation on interaction of 3-D Oblique Shock Wave and Sidewall in Restricted Channel

中文关键词: 超音速气流  斜激波  斜激波反射  受限通道  斜劈

英文关键词: Supersonic airflow  Oblique shock wave  Shock wave reflection  Restricted channel  Ramp

中文摘要:

      为了了解超燃冲压发动机中三维斜激波与壁面的相交情况，以冷态模拟为基础，对两种不同形状的斜劈结构产生的斜激波进行数值模拟。当斜劈展向与气流方向成45°时，激波和膨胀波结构呈现三维特性，并且激波在两侧壁面处的反射现象不同。以激波面上游为视角,当激波与壁面相交成锐角时会产生马赫反射；而激波与壁面相交成钝角则会以叠加膨胀波的形式减弱激波，并且使激波面的法线方向与壁面的法线方向垂直。由于两侧壁面的影响，随着高度的增加激波强度减弱，同时气体经过斜激波后偏转角度也减小。对于构型II，有斜劈的区域产生三维斜激波会延伸到无斜劈区域，此时下壁面与斜激波相交成钝角，同样会以叠加膨胀波的形式减弱斜激波。

英文摘要:

      In order to understand the interaction of the 3-D oblique shock wave and the wall in the scramjet engine, the 3-D oblique shock wave in cold airflow was numerically simulated in two different shapes of the ramp tunnel. When the angle of the ramp span wise and the airflow direction was 45°, the structure of the oblique shock wave and expansion wave showed a conspicuous 3-D character and the reflection mechanism at each sidewall was different. If the upstream of the oblique shock wave was as an viewpoint, Mach reflection happened when the angle of the shock wave and sidewall was acute angle. However, the oblique shock wave was weakened by the expansion wave superposition，and the normal direction of the shock wave was perpendicular to that of the sidewall when the angle of the shock wave and the sidewall was obtuse angle. With the increase of the height, the shock intensity decreases and the deflection angle decreases as the gas passes through the oblique shock wave. For the ramp of constructionⅡ, the ramp area produces 3-D oblique shock wave, and the oblique shock wave will be extended to a flat rectangular area, meanwhile it would be weakened by the expansion wave superposition when the angle of the shock wave and the lower wall was obtuse angle.