超声速转子叶片非定常引射器流场特性数值模拟

Numerical simulation of flow mechanism of unsteady supersonic rotor-vane ejector

采用计算流体力学方法,结合适当的边界条件,对超声速转子叶片非定常引射器进行了模拟。从结果可以看出:此类引射器内流态复杂,主气流出口斜激波干扰现象明显,叶片设计参数对引射器性能影响很大。叶片尾部的膨胀波有效诱导了被引射气流,在短距离内增强了气流混合,湍流效应对引射器性能的影响较小;叶片可维持自旋转,提升叶片转速可增强引射效率。最后,对引射器内的流动机理进行了探讨。

Computational fluid dynamics(CFD)with proper boundary conditions was used to compare the performance of different states for capacity of entropy production control,or decrease of the pressure loss.Numerical results show that the flow field in supersonic rotor-vane is complex,phenomenon of interference between oblique shocks is obvious.The expansion shock of rotor tail induces the secondary flow and enhances the mixing of two fluids of different energy at short distance.Comparing mixing by gas-shock with shear between two fluids,the effect of turbulence is weak,even ignorable.The position and shape of the vane, such as the tail part,leading edge,the height of leading part,has an important effect on the flow regimes and efficiency of ejector. The compression-ratio and entrainment-ratio of the ejector is in proportion to rev of rotor.The rotor and vane could be free rotary with proper setting angle of vane.Furthermore,investigation on flow mechanism and efficiency of ejector is given.