进口形状对内转式进气道的起动特性影响

为了研究进口形状对高超声速内转式进气道低马赫数起动特性的影响,设计了分别具有矩形、正方形、椭圆形、圆形进口形状的4个进气道,然后利用仿真方法对其不起动/再起动流场结构进行了分析.结果表明:矩形和椭圆形进口进气道的再起动马赫数相近,正方形和圆形进口进气道的再起动马赫数相近,且后两者的再起动马赫数偏高.进一步分析发现,再起动能力的差异可能是由进口的宽高比不同所导致,因此设计了不同宽高比系列的进气道,并对其不起动/再起动流场结构进行了研究.结果表明:进口宽高比对进气道起动性能具有显著影响,在一定范围内宽高比越大,其再起动能力越强. 

Effect of entry shape on starting characteristics of inward turning inlets

In order to investigate the low Mach number starting characteristics of hypersonic inward turning inlets, four kinds of inlets with rectangular, square, elliptical and round entry shapes were designed. Simulation method was used to investigate their unstarting/restarting flow-field structures. Results show that, the inlets with rectangular and elliptical entry shape have similar restarting Mach number while the inlet with square and round entry shape have the similar and higher restarting Mach number. Further analysis shows that the difference of restarting capability may be caused by the different aspect ratios of the entry shape, therefore, a series of inward turning inlets with different aspect ratios were designed, and their unstarting/restarting flow-field structures were investigated. Results show that the aspect ratio of the entry plays an important role in inlet starting characteristics of inward turning inlet. The larger aspect ratio means the easier inlet restarts.