圆转矩形大宽高比收敛喷管过渡型面及喷口形式对射流掺混特性的影响

Influence of high aspect ratio convergent nozzle with different transition cross-section and nozzle shape on jets mixing characteristics

设计了一组宽高比为8的不同形式的矩形喷口,对其尾喷流掺混特性进行了数值模拟.通过改变圆到矩形过渡段的型面,在喷管出口下缘加装下挡板以及在侧面加装挡板,得到了4种不同形式的矩形喷管模型,分别在相同边界条件下研究了它们的射流掺混特性.结果表明,加装下档板和侧档板能够有效增强射流掺混,缩短射流高温区长度.

The mixing characteristics of jets from four rectangular nozzles with aspect ratio of 8 were investigated by numerical simulation. The first and second nozzles had different transition sections from circular to rectangular, the third nozzle had a rectangular flip which was an extension of the bottom wall of nozzle exit on the base of the first one, while the last one had two triangular flips on the left and right sides of the nozzle exit on the base of the third one. The results show that the mixing characteristics of the two nozzles with different transition sections have little difference, while the flips cause strong mixing.