带有悬臂预喷注结构的压缩斜楔流场特性研究

Flow Field Characteristics of Ramp with Cantilevered Injector

关键词:  预喷注  悬臂喷注器  燃料掺混  数值仿真  流场特性  进气道

Key words:  Pre-injection  Cantilevered injector  Fuel/air mixing  Numerical simulation  Flow field characteristics  Inlet

摘要:

为给前体带有悬臂预喷注结构的吸气式高超声速飞行器进气道设计提供参考，本文设计了一种带有悬臂预喷注结构的压缩斜楔模型，采用数值仿真方法研究了该结构喷注前后的流场特性，并分析了悬臂截面形状变化以及悬臂外径变化对该流场的影响。结果表明：在楔面上设置悬臂预喷注结构，其产生的诱导激波会增加楔面激波的强度和激波角，并在悬臂下游产生一定范围的低总压区域，喷注后在悬臂喷注结构下游可获得面积较大、距壁面一定距离且氢气与空气分布较均匀的掺混区域。不同悬臂截面形状对楔面激波的影响较小，使用方形截面的悬臂结构会增加悬臂下游低总压区域的范围，但氢气与主流的掺混性能有显著提高。增加悬臂外径会使悬臂诱导激波对楔面激波的影响增加，悬臂后方低总压区域的范围增大，但在本文研究范围内对氢气与主流的掺混性能影响较小。因此，在前体带有预喷注结构的进气道设计过程，可根据要求选择合适的悬臂截面形状，而在使用圆形截面悬臂时尽可能选择较小的悬臂半径。

Abstract:

In order to provide reference for the design of hypersonic inlet with cantilevered injectors set on its forebody， a compression wedge model with cantilevered injector was designed. The flow field characteristics were obtained by numerical simulation method， and the influence of section shape and outer diameter of cantilever on the flow field was analyzed. The results show that the cantilevered injector will induce a shock which can increase the intensity and shock angle of wedge shock， and produce a certain range of low total pressure region downstream of the cantilever. A large mixing area， at some distance from the wall， with uniform distribution of hydrogen and air can be obtained downstream of the cantilever injector structure. Different cantilever section shapes have little effect on the wedge surface shock wave. Using cantilever injector of square section will increase the range of low total pressure region downstream of the cantilever injector， but the mixing performance of hydrogen and the main stream is significantly improved. Increasing the outer diameter of the cantilever enhances the influence of cantilever induced shock on the wedge shock， and increases the range of low total pressure area behind the cantilever. However， within the scope studied in this paper， its influence on the mixing performance of hydrogen and mainstream is small. Therefore， in the design process of inlet with cantilevered injector， the appropriate cantilever section shape can be selected according to the requirements， while the cantilever radius can be selected as small as possible when the circular section cantilever is used.