高超声速进气道快速破膜开启的流动特性  

Flow characteristics of hypersonic inlet starting with diaphragm rupture

作　　者：徐骁[1] 岳连捷[1] 卢洪波[1] 肖雅彬[1] 张新宇[1] 

机构地区：[1]中国科学院力学研究所高温气体动力学国家重点实验室,北京100190

出　　处：《航空学报》2015年第6期1795-1804,共10页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(91216115)~~

摘　　要：进气道处于起动状态是保证超燃冲压发动机正常工作的前提,进气道帽罩快速开启时的非定常效应可以有效提高进气道的起动能力。采用非定常数值计算深入研究了唇口帽罩不同安装位置开启时的非定常效应对进气道起动过程的影响,分析了不同帽罩安装位置开启时进气道流场的演化过程,并揭示了喉道分离泡的形成机理。研究结果表明,当帽罩上游不存在分离泡时,破膜非定常激波在压缩面反射,与上游复杂波系作用形成沿壁面的低速流,在唇口激波作用下在喉道形成分离泡。帽罩安装靠近唇口可通过缩短激波/边界层作用距离减小低速流动区范围,进气道临界起动内压比随之增大;而当帽罩上游出现大分离泡时,分离泡会先演变为低速流,之后在唇口激波作用下重新聚集形成大尺度分离,进气道临界起动内压比显著降低。Reliable in-flight starting of the hypersonic inlet is of critical importance for the successful operation of scramjet engines and taking the method of diaphragm rupture can effectively improve the inlet starting ability due to unsteady flow effect, in this paper, time-accurate computations have been performed to investigate the effects on inlet starting process at different diaphragm positions. The evolution process of the inlet flow pattern is analyzed and the mechanism of the separation bubble formation in the throat is thus elucidated. The results show that the unsteady reflected shock interacts with the interface and expansion waves to trigger a low-speed flow when no separation bubble occurs in front of the diaphragm. A separation bubble then forms in the inlet throat, resulting from the low-speed flow under the interaction of cowl shock. Installing the diaphragm downstream would improve the inlet starting ability by decreasing the low-speed flow area. When large separation bubble occurs in front of the diaphragm, the separation bubble will first evolve to a low-speed flow after diaphragm rupture then develop to a new separation in the throat. The inlet starting ability degrades significantly.

关 键 词：高超声速进气道 破膜开启 非定常效应 激波边界层相互作用 分离流 

分 类 号：V214.8[航空宇航科学与技术—航空宇航推进理论与工程]