用非线性涡粘性模式计算三维湍流边界层

针对非线性涡粘性模式在求解三维湍流边界层流动时的不足，本文从压力－变形率关联项中的快速项出发，考虑流动非均匀影响，在显式代数应力模式的雷诺应力表达式中引入了反映雷诺应力“松驰”效应的速度二阶导数项，构造了一个新的非线性涡粘性模式。通过对典型算例－翼体角隔流动的计算结果表明，新模式能较好地再现出三维湍流边界层内雷诺切应力方向的发展滞后于速度梯度方向发展这一流动特性。

Numerical simulation of three-dimensional turbulent boundary layer with nonlinear eddy-viscosity model

Owing to the inadequacy of prevailing nonlinear eddy viscosity model (NEVM) to simulate the three dimensional turbulent boundary layer(3DTBL), the model expression of the pressure strain correlation term is reconsidered. By taking the inhomogeneous effect of the 3DTBL flow into account in the rapid part, a new pressure strain correlation term is obtained and further leads to the derivation of another new NEVM. In this new model, the partial difference of strain rate is introduced into the Reynolds stress expression to represent the relaxation effect of the Reynolds stress. After using this NEVM to the numerical simulation of the wing body junction flow, it is shown that the new NEVM can capture the main characteristic of this 3DTBL flow, i.e., the direction of Reynolds stress lagging behind the direction of velocity gradient.