超声速来流下混合流动控制射流角度影响数值研究

Investigation on the influence of injection angle in supersonic flow with hybrid flow control

为探索混合流动控制器对隔离段气动性能影响,对来流马赫数2.0条件下混合流动控制器的控制特性开展了数值模拟研究,着重比较了射流俯仰角和偏航角对流动控制的影响,结果表明:给定射流位置时,俯仰角的变化仅小幅度改变角区低速回流区的轴向位置,但对回流区范围以及角涡强度有较大影响,其中俯仰角取45°和60°时,回流区范围最小;由于微型涡流发生器上方高速流场的冲击,射流俯仰角越大,混合流动控制器形成的流向涡高度反而越低;偏航角取30°时,随着偏航角的增加,隔离段抗反压能力、流场质量先提升后降低,偏航角过大会导致流场的明显不对称,偏航角取45°时的综合性能最优异;采用较小的俯仰角和偏航角可有效降低总压损失。

The supersonic flow （Ma=2.0） past micro-ramps and micro vortex generator jet have been simulated to suppress boundary layer separation and improve the characteristics of isolators. In this paper, the effects of skew and pitching injection angles on the flow field are analyzed. The pitched angle has little effect on the x position of the separation region in the corner, but greatly changes the length of the separation region and the corner vortex strength. The smallest separation region is generated at pitching angles 45° and 60°. The height of streamwise vortex can be reduced by relatively high pitching angle due to the interactions between the high speed flow and the micro vortex generator. With the increasing skew angle, the flow quality in the isolator increases in the beginning and then decreases. A similar tendency is observed in the ability of the isolator withstanding back pressure. Excessively high skew angle leads to asymmetry flow filed, and the best control action is obtained at 45° skewed angle for the given pitched angle of 30°. Relatively low pitching angle and skew angle are helpful in reducing the distortion coefficient and total pressure loss coefficient.