扩散界面浸入边界法结合壁面模型在湍流模拟中的应用

提出了一种模拟高雷诺数湍流的扩散界面浸入边界法（IBM）。该方法采用壁面模型来减少壁面附近的网格量。为了实施壁面模型和边界条件，在物面外部设置了2个辅助层（一系列拉格朗日点）：外侧的参考层用于实施壁面模型来得到壁面剪应力，内侧的强制层用于实施离壁的边界条件。在实施壁面模型时，将动量方程沿物面法向积分，从而把物面切向的速度修正量与由壁面模型得到的壁面剪应力联系起来，而速度的法向分量则按二次曲线分布来近似重构。在实施边界条件时，为了严格满足无穿透条件，应用了基于隐式速度修正的IBM。最后，利用绕平板湍流和绕NACA0012翼型湍流来对方法的可行性进行了验证。

Wall model based diffuse-interface immersed boundary method and its application in turbulent flows

A diffuse-interface Immersed Boundary Method (IBM) for simulating high Reynolds number turbulent flows is proposed. This method uses the wall model to reduce the number of grids near the wall. To implement the wall model and boundary conditions, two auxiliary layers (a series of Lagrangian points) are set outside the wall: the outer reference layer carries out the wall model to calculate the wall shear stress, and the inner enforced layer implements boundary conditions off the wall. When the wall model is implemented, the momentum equation is integrated along the normal direction of the wall, such that the tangential velocity correction is related to the wall shear stress obtained by the wall model, and the normal component of the velocity is approximately reconstructed according to the parabolic distribution. Furthermore, when implementing boundary conditions, we adopt the implicit velocity correction-based IBM to satisfy the non-penetration condition. Finally, the feasibility of this method is verified by numerical simulation of the turbulent flows around the flat plate and the NACA0012 airfoil.