机翼翼端与固壁之间隙流动的数值模拟

本文通过求解不可压缩流体RANS方程,对机翼翼端与固壁间隙流动进行了数值模拟。计算采用Chiorin提出的人工可压缩性方法及Baldwin-Lomax零方程湍流模式。针对间隙流动的特殊性，引进了流场分块的思想以降低网络生成难度、提高网络质量。为了验证计算方法的精度，首先对三维叶栅与固壁之间隙流动进行了数值模拟，计算结果与试验比较吻合良好。在此基础上，对高雷诺数下机翼翼端与固壁间隙的流流动进行了数值模拟，着重是隙的变化对机翼总力的影响、翼端分离涡的形成和发展以及导边附近马蹄涡的出现和消失、间隙内二次流动的特征待方面进行了分析。

Numerical Simulation of Viscous Flow between Wing-Tip and Wall

The viscous flow between the wing-tip and the wall is simulated by solving the RANS equations of incompressible fluid. The computational model is based upon Chorin' s artificial compressibility formulation and the Baldwin-Lomax zero-equation turbulence model. To avoid difficulties in grid generation in the tip-clearance region, a multi-block grid structure is introduced into the present research. For validation of the present method, computations are carried out first for a cascade and the results agree well with experimental data. Then the tip-clearance flow for a single wing is numerically studied. Several features,which are typical of tip-clearance flows, are investigated, such as the influence of clearance width upon the overall hydrodynamic forces, formation and development of the tip-leakage vortex and leading-edge horseshoe vortex, and the secondary-flow characteristics in the clearance.