流向涡对二元进气道流场与性能的影响

Effects of Streamwise Vortex on Flow Field and Performance of Two-Dimensional Inlet

关键词:  曲面压缩进气道  流向涡  进气道性能  分离区  数值仿真

Key words:  Curved compression inlet  Streamwise vortex  Inlet performance  Separation zone  Numerical simulation

摘要:

针对超声速情况下流向涡进入进气道并影响其正常工作的问题，在来流马赫数2.7条件下开展数值研究。进气道模型使用二维曲面压缩进气道，涡流发生器使用有限展长机翼。通过改变机翼攻角和法向高度，研究了两种强度流向涡从四种位置进入进气道时对流场特性和进气道性能的影响。结果表明，两种强度的流向涡与进气道波系相互作用后均未破碎，属于典型的弱相互作用。进气道内收缩段入口附近的分离区在流向涡影响下出现明显的三维非对称特征。此外，随着流向涡接近边界层，分离区的分离点逐渐向上游移动。在流向涡的影响下，进气道的流量系数和总压恢复系数均出现下降，并且流向涡的强度越强、距离边界层越近，对进气道性能的不良影响越明显。特别地，在最大攻角和最低位置的工况下，进气道内收缩段入口上游形成了大规模的分离区，使得入口截面流场的畸变系数相比均匀来流情况增大了约4倍，流量系数下降了约6.1%，总压恢复系数下降了约17.2%。

Abstract:

The streamwise vortex entering the inlet at supersonic speed will affect its normal operation. In order to solve this problem， a numerical study is carried out at a freestream Mach number of 2.7. The inlet model is a two-dimensional curved compression one， and the vortex generator is a finite span wing. By changing the attack angle and the normal height of wing， the flow field characteristics and the performance of inlet effected by streamwise vortices of two different strength from four different positions are studied. The results show that the two vortices of different strength do not breakdown after the interaction with the inlet shock wave， which are typical weak interactions. Under the influence of streamwise vortex， the separation zone near the entrance of the contraction section shows obvious three-dimensional asymmetric characteristics. In addition， as the streamwise vortex approaches the boundary layer， the separation point of the separation zone gradually moves upstream. Under the influence of the streamwise vortex， the flow coefficient and the total pressure recovery coefficient of the inlet decrease， and the stronger the streamwise vortex is and the closer it is to the boundary layer， the more obvious the adverse effect on the performance of the inlet becomes. In particular， under the conditions of the maximum attack angle and the lowest position， a large-scale separation zone is formed in the upstream of the entrance of the contraction section， which increases the distortion coefficient of the entrance of the contraction section by about 4 times， decreases the flow coefficient by about 6.1%， and decreases the total pressure recovery coefficient by about 17.2%.