进气预旋对环形混合器混合排气系统气动热力性能的影响

为了明确混合排气系统内涵进气预旋角对环形混合器混合排气系统气动热力性能的影响,采用基于Navier-Stokes方程组的三维流场数值仿真方法对某环形混合器混合排气系统在不同进气预旋角工况下的流场进行了分析,并将结果同轴向进气的情况进行了对比.结果表明:内、外涵之间剪切层的厚度以及剪切层的扭曲程度随进气预旋角的增加而增大.在环形混合器混合排气系统出口处,随着进气预旋角的增加,热混合效率小幅升高,其中30°进气预旋角模型热混合效率为轴向进气模型的1.36倍;总压恢复系数和环形混合器混合排气系统推力逐渐降低,较轴向进气模型,30°进气预旋角模型总压恢复系数降低了0.0034,而相对推力下降了0.081. 

Effect of inlet preswirl on the aerothermodynamic performance of splitter mixing exhaust system

In order to clarify the effect of core flow inlet preswirl angle of mixing exhaust system on the aerothermodynamic performance of splitter mixing exhaust system, investigation on the flow field of splitter mixing exhaust system at different inlet preswirl angles was carried through the three-dimensional numerical simulation based on Navier-Stokes equations, and the results were compared with flow along the axis. According to the results, the thickness of shear layer increases with the inlet preswirl angle, and it is the same with the twist of shear layer. Besides, at the splitter mixing exhaust system exit, as the inlet preswirl angle increases, the thermal mixing efficiency increase slightly and thermal mixing efficiency of 30 degree inlet preswirl angle model is 1.36 times the model with flow along the axis. Moreover, total pressure recovery coefficient and thrust of splitter mixing exhaust system also decline. Compared with the model with flow along the axis, the total pressure recovery coefficient of 30 degree inlet preswirl angle model falls by 0.0034 and its relative thrust declines by 0.081.