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双模态超燃冲压发动机由于压力扰动可能发生不起动现象,造成推力严重下降,对飞行稳定性与飞行安全具有很强的破坏性.不起动初始阶段主要受到激波与边界层相互作用引起的流动分离影响,希望通过控制分离达到改善流动的目的.采用5阶特征型WENO(weighted essentially non-oscillator)格式与3阶TVD(total variation diminishing)型Runge-Kutta(R-K)格式的高精度数值方法,求解三维Navier-Stokes(N-S)方程,研究与分析了凸起物和被动吹吸两种被动控制方法对激波与边界层相互作用导致的高超声速流动分离现象的控制效果.结果表明:凸起物通过诱导流向涡形成,改变空间压力分布,减弱二次分离,影响分离结构;吹吸方式的被动控制技术通过平衡分离区与再附区之间的高低压差,降低逆压梯度,使压力分布与分离区域发生改变.
The bimodal scramjet may not start due to pressure disturbance, resulting in a serious decline in thrust and strong destructiveness to flight stability and flight safety. The initial stage of non-start-up is mainly caused by the interaction between the shock wave and the boundary layer Flow separation, and hope to achieve the purpose of improving the flow through the separation of control.Using the method of weighted essentially non-oscillator (WEN) and Runge-Kutta (RK) of third order TVD (total variation diminishing) , The Navier-Stokes (NS) equation is solved and the control effect of hypersonic flow separation caused by the interaction between shock wave and boundary layer is studied and analyzed by two kinds of passive control methods such as bump and passive blowing. The results show that convex By inducing the flow of vortex into the formation of changes in space pressure distribution, weakening the secondary separation, affecting the separation of structure; blowing suction passive control technology by separating the separation zone and re-attachment of the high and low pressure gradient, reducing the pressure gradient, so that Pressure distribution and separation areas change.