Ma = 3.5外并联双通道 TBCC进气道动态节流过程非定常耦合特性

Transient Flow Coupling Characteristics of Ma = 3.5 Externally Paral-lel Dual-Channel TBCC Inlet During Dynamic Throttling Process

摘要:

TBCC进气道在宽域马赫数飞行器性能提升方面起着重要作用。文章对外并联 TBCC进气道在 Ma = 3.5状态下双通道共同工作过程进行了非定常仿真。首先,随着涡轮通道反压的逐渐增加,结尾激波串不断向上游移动,研究发现涡轮通道反压比从 30增加到 49.6的过程中,泄流在涡轮通道调节过程中可以起到稳定结尾激波串的作用,放气流量从 2.80%增加至 4.39%,使结尾激波串位置移动相对较小。当结尾激波串推出流道,进气道陷入不起动状态后,涡轮进气道的喘振会使流场中的分离显著向前体延伸,从而诱发冲压通道的不起动。相比之下,冲压进气道的喘振过程对涡轮进气道流场结构影响相对较小,壁面压力分布表明冲压进气道的喘振会引起涡轮进气道压力波动 0.2~0.4倍反压,并伴随高频振荡。研究结果表明,分流板与进气道主体连接处的泄漏对改善任何通道的气动性能并无益处,因此应尽量减少泄漏。

Abstract:

The TBCC inlet plays an important role in the performance enhancement of wide-operating vehicles. An un-steady simulation of the dual-channel co-operating process of an externally-parallel TBCC inlet in the Ma = 3.5 state is car-ried out. Firstly, with the gradual increase of the turbine channel backpressure, the terminal shock train keeps moving up-stream, and it is found that during the increase of the turbine channel backpressure ratio from 30 to 49.6, the bleeding flow can play a role in stabilizing the terminal shock train in the turbine channel regulation process, and the bleeding flow rate increases from 2.8% to 4.39%, so that the position of the terminal shock train moves relatively very tiny. When the terminal shock train expels out of the channel and the turbine channel falls into unstart, the unstart of the turbine inlet channel forces the separation to extend significantly into the forebody, thus inducing the unstart of the ramjet channel. In contrast, the throttling process of the ramjet inlet has relatively little effect on the flow field structure of the turbine chan-nel, and the wall pressure distribution indicates that the pressure fluctuations of the turbine inlet keeps in the range of 0.2 to 0.4 P0, accompanied by high-frequency oscillations. Finally, the results suggest that the leakage at the junction of the manifold and the inlet body does not contribute to the improvement of the aerodynamic perforMance of any of the chan-nels, and therefore should be minimized.