Bump进气道中鼓包诱导的激波/边界层干扰特性

为了探索Bump进气道中鼓包诱导的锥形激波和机身发展而来的湍流边界层干扰问题,分析其气动优势,首先选取了半锥和半棱锥这两种与鼓包的流场结构具有一定相似性的构型作为参照,采用数值仿真方法,分别对这三类典型的三维激波/湍流边界层干扰问题进行了流场分析。在此基础之上,设计了三个不同马赫数的鼓包,并研究了设计马赫数对鼓包流场特性的影响。结果表明:当三类构型的无黏激波强度相等时,半锥诱导产生的旋涡强度最强,鼓包次之,半棱锥最弱。尽管鼓包诱导的流场非常复杂,其干扰流场却呈现出准锥形相似的特性。虽然半锥对边界层的排移能力最强,但是综合考虑边界层排移能力及进气道出口流场畸变下,鼓包最具优势,这也是其被选为超声速进气道前缘压缩面的重要原因之一。此外,在设计状态下,适当增加设计马赫数能改善鼓包排移边界层的能力,但设计马赫数太高,边界层排移能力基本不变,反而使得进气道总压损失急剧增加。 

Shock wave/boundary layer interactions induced by bump in the Bump inlet

In order to study the interactions between the conical shock wave induced by the bump of the Bump inlet and the turbulent boundary layer developed from the fuselage, and also estimate its aerodynamic advantages, the semi cone and semi rhombic cone of some similarities in flowfield structure with bump were selected as references. The three dimensional flowfields with these three configurations were simulated by numerical methods. Based on this, three bumps with different Mach numbers were designed and the effect of the designed Mach number on the bumps flowfield characteristic was studied. The results showed that when the inviscid shock wave strengths of three configurations were equal, the strength of the vortices induced by semi cone was the strongest, followed by the bump, and that induced by the semi rhombic cone was the weakest. Although the flowfield induced by the bump was very complex, the flow field behaved in quasiconical similarity manner. Although the semi cone had the strongest ability to divert the boundary layer, considering the ability of diverting the boundary layer and the inlet exit distortion on the whole, bump was the best, showing why it was selected as the leading compression ramp for supersonic inlet. In addition, at the design condition, increasing the design Mach number appropriately can improve bumps ability of diverting the boundary layer. However, in case of too high designed Mach number, the ability of diverting the boundary layer could almost keep invariant, but the total pressure loss may increase rapidly.