强制转捩对高超声速进气道性能影响

针对一个高超声速进气道，设计了不同高度的钻石形和斜坡形转捩带，在来流马赫数为6，攻角为1°工况下，通过风洞试验与三维数值模拟相结合的方法，研究了转捩带对进气道壁面热流密度、压强、隔离段入口处总压和马赫数分布的影响.数值计算与风洞试验在壁面压强、进气道总压和马赫数上吻合较好，在壁面热流密度上相差约35%.研究结果表明:钻石形和斜坡形转捩带都可以有效地实现强制转捩.此外，随着转捩带高度的增加，转捩区域逐渐前移，直至转捩带后缘.对于已经起动的进气道，转捩带对进气道下壁面静压几乎不产生影响，但会使得隔离段下壁面附近的总压和 马赫数有所下降，从而导致从隔离段入口直至整个隔离段的质量加权总压和流量均下降3.5%左右，而质量加权马赫数的下降量则并不明显，在1%左右. 

Effect of forced-transition on performance of hypersonic inlet

Diamond and ramp forced-transition trips with different heights were designed for a hypersonic inlet. On the condition of freestream Mach number 6 and the angle of attack 1 degree,the effects of forced-transition on wall heat flux distribution, pressure, total pressure and Mach number of isolator inlet were investigated by both wind-tunnel experiment and three-dimensional numerical simulation. The computational data agreed well with wind-tunnel experiment results in wall pressure, inlet total pressure and Mach number. And there was at most 35% difference in wall heat flux between simulation and experiment results. The results show that both the diamond and ramp forced-transition trips can promote forced-transition effectively. The transition location moves forward with the increasing height of the trips. For the started inlet, the forced-transition trips have little effect on the static pressure of the inlet bottom surface, but the total pressure and Mach number near the bottom surface of the isolator will decline; in such case, the mass-averaged total pressure and the mass flow rate in the isolator decline about 3.5%. The decline of the mass-averaged Mach number is only about 1%.