【摘要】 本文将“Partially Parabolic”流动假设运用于有纵向曲率、有压力梯度、壁面有排孔喷射的弯曲通道内,孔附近气膜冷却流场。支配方程是部分抛物化的Navier-Stokes方程及滞止焓方程。湍流粘性系数由K-8双方程模型决定,而在边界层内层区则采用双层模型。在本文所建议的变步长准正交曲线坐标系下,用有限差分法对平坦通道及弯曲通道凸壁面一侧离散孔垂直喷射及斜向喷射气膜冷却有效温比作了计算。在吹风比较小的条件下,计算结果清楚地显示了三维气膜冷却的特征。与已有的典型实验结果比较,变化趋势是完全一致的。对于吹风比较大的情况,则必须求解完全的Navier-Stokes方程。更多还原

【Abstract】 Partially parabolic hypothesis has been used to predict film-cooling flow field near the injection holes in a longitudinally curved channel in the presence of pressure gradient with coolant injected through a row of holes on the wall surface. Governing equations are partially parabolized Navier-Stokes equations and stagnation enthalpy equation. Turbulent eddy viscosity is determined by K-ε two-equation model, while, in the inner layer of the boundary layer, two-layer model is used. In the semi-orthogonal curvalinear coordinate system suggested by the anthers, the film cooling effectivenesses for normal-to-surface injection and inclined injection on a flat and convex surface are calculated by finite difference method. In the case of lower blowing rates, the three dimentional features of the film-cooling flow field have clearly been shown; In the case of higher blowing rates, however, solution of the full Navier-Stokes equations is necessary.更多还原