新型斜波瓣超声速混合器设计研究及其数值计算

根据超声速两股流掺混的特点, 在波瓣喷管的基础上提出了一种新的斜波瓣型超声速混合器设计方法, 设计的原则是在较小流动损失的前提下尽可能增加混合程度.利用有限体积法对三维可压粘流N-S方程进行离散, 紊流模型为k-ε模型, 分别对欠膨胀、接近完全膨胀和过膨胀3种工况进行了计算研究.计算结果表明, 当内通道瓣腔顶端与外通道相交处成一定夹角, 射流产生鞍形激波和旋涡可以增加掺混效率, 混合器内两股超声速流的流态基本符合设计要求.在欠膨胀、接近完全膨胀的工况, 效果是令人满意的, 但对严重过膨胀的工况, 到出口截面的混合效果不理想. 

Study and numerical calculation on the new design method for supersonic mixer of sloped lobed shape

According to the mixing feature of two supersonic flow streams,a new design method of supersonic mixer of sloped lobed shape was presented based on the concept of lobed nozzle.The principle of design is to achieve high efficient mixing at low flow loss.A finite volume method was used to solve the three dimensional compressible viscous Navier-Stokes equations,and the turbulence model was k-ε model.The numerical simulation for under-expansion,optimum-expansion and over-expansion situation has been completed.The calculated results show that the vortex and saddle-shape shock wave caused by the jet can improve the mixing efficiency at a special angle between the top of the inside passage and outside passage.The flow condition of the two supersonic flow streams in the mixer meets the design requirements.The result of under-expansion,optimum-expansion is satisfactory,but the result of over-expansion is not good enough.