波瓣喷管-狭长出口弯曲混合管引射混合特性分析

针对波瓣喷管和具有狭长出口的弯曲混合管所构成的引射-混合系统,进行了引射和混合特性的实验和数值研究,获得了主流和引射气流相互混合过程中的速度场、压力场和温度场的相关信息,以及表征引射-混合系统总体性能的引射系数和总压恢复系数等结果,对比表明数值计算和实验数据的相对误差在15%以内。由于弯曲混合管的出口狭长,弯曲混合管的混合流动受到流向旋涡和弯管二次流的共同影响,形成了有别于常规椭圆形出口截面混合管的一些独特的流动现象和特征。

Investigation on Ejecting and Mixing Characteristics of Lobed Nozzle with Curved Mixing Duct and Slot Exit

A combined experimental and computational study on ejecting and mixing characteristics of the lobed nozzle with curved mixing duct and slot exit was performed.The velocity fields,pressure fields and temperature fields,as well as the ejection coefficient and pressure recovery coefficient which reflect the overall characteristics of mixer-ejector system were obtained.It is indicated that the relative error between the computational and experimental results is about 15%.As the exit of the curved mixing duct is a narrow slot,the flow process inside mixing duct is affected by streamwise vortices and secondary circulation,which forms some special flow phenomena and features compared to common curved mixing duct with elliptical exit.Because of the existence of secondary flow caused by the curved duct,the streamwise vortices formed at the lobed nozzle trailing edge are strongly destroyed in the developing process,and the velocity and temperature distribution features are not similar to that in short curved mixing duct with elliptical exit.