为了获得更好的混合效果, 将3股互击式喷注器中间的喷注孔与两侧的喷注孔进行异型设计, 改为直孔与锥形孔的组合, 得到两种新型结构的3股互击式喷注器。应用计算流体力学方法, 在“燃料-氧化剂-燃料”组合条件下, 对上述两种结构及全直孔式喷注器的流场进行了3维的数值模拟。互击式喷注器主要通过横向旋涡驱动来实现快速混合; 氧化剂喷注采用锥形孔后, 旋涡强度偏低, 而燃料喷注采用锥形孔后, 旋涡强度则有所提高。选取质量加权平均的未混合度作为评价参量, 比较了3种不同喷注器结构的混合效果, 发现燃料喷注采用锥形孔的3股互击式喷注器混合效果最好, 全直孔式居中, 氧化剂喷注采用锥形孔的最差。结果表明, 对化学激光器燃烧室喷注器的设计而言, 可考虑对两种喷注孔进行异型设计, 如将燃料喷注改用锥形孔, 以便进一步改善混合效果。

In order to enhance mixing effect, two novel styles of triplet impingement injectors were presented by changing middle jet orifice or the other two jet orifices into cone-shaped orifices. Flow field characteristics of above-mentioned two kinds of injectors and traditional injectors with triple straight-wall jet orifices under conditions of fuel-oxidizer-fuel triplet arrangement were analyzed based on 3-D computational fluid dynamic methods. The numerical simulation results demonstrate that mixing of triplet impingement injectors is principally accelerated by transverse vortices. For the injector with cone-shaped oxidizer jet orifice, the vertex intensity of flow field is lower than that of the injector with triple straight-wall jet orifices. For the injector with cone-shaped fuel jet orifices, there is a definite increase of the vertex intensity of flow field. Mass-weighted average unmixedness was introduced to evaluate the mixing performances of three kinds of injectors. It is indicated that the mixing effect of injector with cone-shaped fuel jet orifices is better than that of injector with triple straight-wall jet orifices and the injector with cone-shaped oxidizer jet orifice is the worst of three. For injector design of chemical laser combustors, oxidizer and fuel jet orifices adopt different styles, for example, the injector with cone-shaped fuel jet orifices, which helps improve mixing effect of oxidizer flow and fuel flow further.