【摘要】 <正> 为了设计高效率高负荷的跨音叶轮机械,气动计算中必须计入粘性的影响。当叶片表面流动不发生分离,或分离区很小时,流道内的流动可以分为叶片表面以及尾缘下游的粘性薄层——边界层和尾迹区以及除此以外的无粘流区。因而可以分别应用欧拉方程组及边界层方程组求解这两个区内的流动。无粘流-粘流的相互影响是通过无粘流计算及边界层计算的一系列迭代计算来实现的:由给定的气动参数及叶栅几何形状进行无粘计算,得到叶片及尾迹表面的流动参数分布,作为首次边界层及尾迹计算的输入数据,求得边界层及尾迹的排挤厚度δ₁,并以此对无粘流动的几何边界进行修正,作为下一次无粘计算的流场边界。这样的迭代重复进行,直到满足全场的总体收敛条件为止,其迭代框图如图所1示。更多还原

【Abstract】 An inviscid-viscous interaction method has been developed to predict the blade-to-blade flow in plane turbine cascades. The interaction effect is taken into account by iteratively solving the inviscid and viscous flows. The inviscid flow is calculated by a finite area time-marching method. The viscous flow is calculated by the integral method- Loitsianskii’s method for laminar boundary layer after performing Illingworth-Stewartson transformation and Green’s lag-entrainment method for turbulent boundary layer and wake. A mixing calculation is carried out to determine the kinetic energy loss coefficient. The exit angle is determined by the base line of the wake predictions agree well with the test results for two transonic turbine cascades.更多还原