圆排波瓣喷管引射器高效掺混流场数值计算

采用贴体曲线坐标、SIMPLEC算法和完全压力修正，在非正交性非常大的结构型同位网格上求解了圆排波瓣喷管引射器内流场的不可压Navier-Stokes方程，湍流采用标准k-ε涡黏模型.计算得到了引射器中热混合效率沿混合管轴向的变化规律和流向涡的演变规律.混合管中的流向涡阵列大大强化了主次流的掺混.但该型引射器的总体热混合效率不高，实验的3种主流温度下最大热混合效率为0.874.将混合管出口截面速度分布和温度分布的数值模拟结果与实验值比较，两者比较一致；模拟结果与混合管沿轴向的静压系数分布规律实验值也基本相同.

NUMERICAL SIMULATION OF ENTRAINED FLOW FIELD IN CIRCULARLY LOBED NOZZLE

In this paper, a numerical procedure to study the mixing flow in a circularly lobed nozzle is presented.The predictions are obtained by using SIMPLEC and complete pressure corrections algorithm to solve the incompressible Navier-Stokes equations.Turbulence is characterized by the standard k-ε eddy viscosity model.To fit the irregular boundaries of the flow field,curvilinear greatly nonorthogonal coordinates are used.The robustness of the computational procedure is enhanced by making use of nonstaggered grids. Results show that the thermal mixing efficiency of primary and secondary flow varies with the axial length of the mixer, and the streamwise vortex development.In the whole, the thermal mixing efficiency is not high, and the maximum value is 0.874.Good agreement between the numerical and experimental results is obtained for the axial velocity and temperature profiles in the outer section of the mixer, and the pressure coefficient on the wall of the mixer along the axial line.