横喷射流与空气混合增强的试验研究

EXPERIMENTAL STUDY ON MIXING ENHANCE MENT OF VORTEX GENERATOR JETS

关键词:  横流  气体喷射  旋涡  混合  氢燃料  冲压喷气发动机

Key words:  Cross flow  Gas injection  Swirl  Mixing  Hydrogen fuel  Ranjet engine

摘要:

提出利用垂直横喷射流引入流向旋涡来增强氢和空气的混合。射流中心剖面速度分布和射流轴线最大速度衰减的五孔探针测量结果表明，单孔射流与来流空气的动量比越大，混合越迅速。二维射流的混合要比三维射流差的多。单排多孔射流在一定的孔面积和流量比下，协调孔距、通道高度和射流动量比的关系，就可获得射流与来流空气的最佳混合，然后据此确定喷孔直径和数目。首次引入三维垂直射流旋涡穿透深度的概念，这比最大速度穿透深度更具实际意义。

Abstract:

Using Vortex Generator Jets to enhance the mixing of gaseous fuel jets and air inlet flow was investigatedThe velocity profile at air jet central symmetry and axial maximum velocity decay measured by five hole probe quantified the mixing ratesThe higher the momentum ratio of single hole jet,the quicker the mixingThe rate of mixing of slot jet was very slower than circular hole transverse jetIt was found that streamwise vortex has a significant effect on the mixing rates,the fast jet mixing could be acquired by adjusting orifice distance,duct height and jet momentum ratioAn important concept Vortex Penetration Depth is first introduced