波瓣喷管结构参数对引射混合器性能影响的数值研究

通过三维CFD数值计算,研究了波瓣喷管几何结构参数对波瓣喷管引射-混合器的影响规律。计算结果表明:瓣宽增加导致引射流量和波瓣出口处速度环量减小,热混合效率降低,但可以减小混合流动损失,提高总压恢复系数。波瓣扩张角的改变,对引射流量的改变因不同混合管尺寸而异,在混合管直径较小时,随着波瓣扩张角在20~°90°范围内增大,引射流量呈先增加后减小的趋势;在混合管直径较大时,引射量持续提高。扩张角的增加可提高速度环量,但是流动混合损失增加,总压恢复系数减小。

Numerical Investigation on the Effects of Lobe Nozzle Geometric Parameters on Mixer-Ejector Performance

Based on three dimensional CFD of the lobed mixer-ejector,the effects of lobe nozzle geometric parameters on the lobed mixer-ejector performance were revealed.The results show that the increase of lobe width causes the rapid decrease of ejection ratio.The velocity circulation at lobe exit section and the thermal mixing efficiency decrease with the increase of lobe width,whereas the pressure recovery coefficient is improved by the increase of lobe width.The effect of lobe diffusion angle on the ejection ratio depends on the mixing duct diameter.For the case of small diameter mixing duct,the ejection ratio increases firstly and then decreases with the increase of lobe diffusion angle from 20 degrees to 90 degrees.For the case of large diameter mixing duct,the ejection ratio increases continuously with the increase of lobe diffusion angle.The increase of lobe diffusion angle results in the increase of velocity circulation at the lobe exit section,but it raises the mixing loss and lowers the pressure recovery coefficient.