涡轮级三维粘性流场的数值模拟

本文给出了一种求解涡轮级三维定常粘性流场的计算方法,并对某型航空发动机的高压涡轮进行了数值模拟。该计算程序考虑到了涡轮级工作温度范围较大而引起的变比热问题。文中采用了三阶精度的ＴＶＤ格式和Ｂ－Ｌ湍流模型。叶列间参数的传递采用了“混合平面”法。叶列间处理采用外推无反射边界条件来保证参数在交接面上的周向不均匀。同时在交接面上构造了Ｒｉｅｍａｎｎ解和使用松弛因子来提高程序在叶列间小间隙情况下的稳定性。

A NUMERICAL SIMULATION OF 3D VISCID STEADY FLOW IN A TURBINE STAGE

A 3D numerical methodology is presented for simulating blade rows in a turbine stage by solving 3D time-dependent compressible Navier-Stockes equations.This numerical method is based on Godnov's finite volume scheme with third-order-accuracy and TVD property.Baldwin-Lomax algebraic turbulence model is employed to simulate largely separated flow.The principal assumptions are made as follows:the flow is steady between stator and rotor and these rows can communicate via inter-row mixing plane.These reformative "mixing planes" introduce circumferential averaging of flow properties but preserve general radial variations.The circumferential disequilibrium in the same row is assured by using non-reflecting extrapolated boundary condition.In view of wide working temperature range in turbine stage,varying specific heat is applied in this method.The calculation instability resulted from inter-row mixing treatment is improved remarkably by using Riemann solver and lax gene in the case of small inter-row gap.The application of this method is illustrated for an axial high-pressure turbine stage in an areoengine.The results show that this method not only is available but also reveals flow phenomenon in rows very well.