不同隔板构型下的超声速混合层流场特性

Study on the flow fields of supersonic mixing layer with splitters of different geometric configurations

利用实验和数值仿真相结合的方法,对Ma1=1.5,Ma2=2.5,T0,1=300K,T0,2=1200K,压力匹配(p1=p2=86kPa)条件下的超声速混合层在不同隔板构型下的流场特性进行了研究。实验中发现在隔板上开凹腔对于混合层具有一定的混合增强效果,且凹腔长深比越大,这种效果越显著。对于尾缘交错分布的隔板,混合层流场显现出强烈的非定常性,且极大地增进了混合。通过相应的数值仿真发现,凹腔隔板的增混机制在于凹腔剪切层的再附着,而交错隔板则在于促进了大尺度流向涡的产生。

Through combining an experiment and a numerical simulation,a study was carried out on supersonic mixing layer with splitters of different geometric configurations,which is under the condition of Ma1 =1.5,Ma2 =2.5,T0,1 =300 K,T0,2 =1200K,and matched pressure p1 =p2=86kPa.In the experiment,it was discovered that the thickness of mixing layer in the flow field with splitters in which a cavity is mounted grows as the ratio of the length to the depth of the cavity becomes larger; Splitters with sawtooth trail show great effect of mixing enhancement and making the flow field highly unsteady.In the numerical study,it was demonstrated that the mixing-enhancement effect of splitters with cavity is due to the cavity shear layer＇ s reattachment to the trail of the splitter,and splitters with sawtooth trail due to induced large-scale streamwise vortexes.