基于涡流发生器的内转式进气道流场组织研究

Flow field organization of inward turning inlet based on vortex generator

内转式进气道唇罩激波/边界层扫掠干扰诱发类锥形涡并进一步发展成空间流向涡,导致低能流向压缩面侧堆积,流场参数分布不均匀。为了改善内转式进气道流场结构,本文采用数值仿真方法开展了涡流发生器(Vortex Generator,VG)及其几何参数对内转式进气道流动特性影响的研究。研究结果表明:VG安装于干扰区内,其诱导形成反向漩涡,减弱了压缩面侧流向涡强度,有效阻碍了低能流向压缩面迁移堆积,促进了低能流与主流掺混,原型进气道隔离段出口大尺度类圆形低总压区被分割成两个小尺度低总压区,有效提升了进气道流场均匀度。在研究范围内,VG高度和安装角影响进气道流动特性,随着VG高度与安装角增大,其诱导的反向漩涡增强,流场均匀度提升,总压恢复系数下降。与原型进气道相比,设计状态,通流条件下VG进气道隔离段出口总压恢复系数与畸变指数DC_(60)分别下降0.54%,36.8%;84,141倍反压条件下,VG进气道隔离段出口总压恢复系数分别上升4.60%,12.0%;有效改善了进气道流动特性。

The swept cowl shock/boundary layer interaction of the inward-turning inlet induces a quasiconical vortex.Further,it develops into the spatial streamwise vortex,resulting in the low energy flow accumulat⁃ing near the compression surface and the uneven flow field.The influence of the vortex generator(VG)and its geometric parameters on the flow characteristics of the inward turning inlet were studied with numerical simula⁃tion to improve the flow field structure of the inward-turning inlet.The research results indicate that the VG in⁃duces the reverse vortex and weakens the intensity of the streamwise vortex near the compression surface when the VG is installed in the interaction zone,and the migration and accumulation of low energy flow towards the compression surface are effectively hindered and promotes the mixing of low energy flow with mainstream flow.The low total pressure zone with large scale and quasi-circular shape at the isolator outlet of the prototypical inlet is divided into two low total pressure zones with small scale,effectively improving the uniformity of the inlet flow field.Within the research scope,the VG height and installation angle affect the flow characteristics of the inlet.With the increase of the height and installation angle of VG,the reverse vortex strengthens,and the uniformity of the flow field improves,but the total pressure recovery coefficient decreases.Compared with the prototypical in⁃let,the total pressure recovery coefficient and the distortion index DC_(60) at the inlet isolator outlet with VG de⁃crease by 0.54%and 36.8%,respectively,under the design and free back pressure condition.The total pressure recovery coefficient at the inlet isolator outlet with VG increases by 4.60%and 12.0%,respectively,under 84 and 141 times back pressure condition.The flow characteristics of the inlet are improved effectively.