三维进气道中弯曲后掠激波/边界层干扰机理与预测方法研究

Three-dimensional inward turning inlet is one of the favorable inlet types in present supersonic/hypersonic vehicle design. Under the condition of integrated design, the characteristics of the shock wave/boundary layer interaction which exists in the leading edge of an inward turning inlet shows distinctive features. The strength and sweepback of the shock are variational along the spanwise direction and the low-momentum flow couples with each other near the symmetry plane in the interaction region. In addition, the strong centrifugal force exists in the interaction region due to the curved interface. Therefore, it is hard to make accurate description and prediction based on the existing theory since such shock wave/boundary layer interaction is much more complex than the one occurs around the simple compression corner. However, the interaction is very important in the inward turning inlet, and even the whole propulsion system, predictable design and high efficient work integrated with a flight vehicle. Therefore, making full use of the supersonic flow test bed and advanced measuring techniques such as NPLS, this project plans to investigate the three-dimensional flow structure and characteristics of the curved swept shock wave/boundary layer interaction in detail. The CFD method is also introduced. The dominant physical mechanism of the curved swept shock wave/boundary layer interaction and the coupling mechanism in both sides of the interaction region will be addressed carefully. At last, the prediction method for this type of shock wave/boundary layer interaction will be built. The achievement of this project will lay a foundation for the advanced integrated design of a high performance inward turning inlet.

三维内转式进气道是当前超声速、高超声速飞行器乐于采用的进气形式之一。在一体化布局条件下，发生于内转式进气道前缘的主压缩激波/机体边界层干扰现象具有变强度干扰、变后掠角干扰、离心力作用显著、两侧耦合干扰等特点，其流动机理和干扰特性均比常规压缩拐角激波/边界层干扰更为复杂，难以直接沿用现有理论和经验模型对其特性进行准确描述和预测，然而其对进气道乃至整个推进系统的可预测设计和高效工作至关重要。本项目拟充分利用课题组超声速流动机理试验台，设计专门的实验模型，借助NPLS等先进的流动显示技术，并结合数值模拟方法，对这种弯曲后掠激波/边界层干扰的三维特性进行细致的研究，旨在阐明弯曲后掠的拐角诱导激波与边界层相互干扰的主导物理机制，揭示流向汇聚的干扰区之间的耦合作用机理及演化过程，并建立相关预测方法，为一体化条件下内转式进气道的先进设计和高效运行奠定理论和方法基础。

在与机体一体化的条件下三维内转式进气道前缘主压缩激波/边界层干扰现象对进气道乃至整个推进系统高效工作有重要影响。该干扰比常规压缩拐角激波/边界层干扰更为复杂，具有变强度、变后掠角、两侧耦合的特点。本项目针对该类干扰现象，结合仿真和试验方法借助抽象的简化模型，掌握了弯曲后掠激波/边界层干扰的精细流场结构，揭示了两侧流向汇聚的干扰区的耦合作用下旋涡演化特性，获得了设计参数对这类干扰的影响规律，并探索建立了可预测分离区尺度的预测方法，研究成果可为一体化条件下内转式进气道激波系配置、进气道参数选择提供参考依据。. 在本项目的资助下，在Journal of Visualization，《推进技术》等期刊发表学术论文9篇，申请国家发明专利3项，获授权2项。