适用于浸入边界法的大涡模拟紊流壁面模型

A turbulence wall layer model for large eddy simulation using immersed boundary method

基于近壁定常剪切应力假设,提出了一种新的适用于浸入边界法的大涡模拟紊流壁面模型。通过引入壁面滑移速度,修正了线性速度剖面计算得到的壁面剪切应力,使之满足Werner-Wengle模型。将其应用于平板紊流和高Re数圆管紊流的数值模拟,对比采用和不采用壁面模型的结果得知,采用此模型的速度剖面与实验值吻合良好,验证了此模型的有效性。研究了不同欧拉/拉格朗日网格相对位置对结果的影响,证明了此模型具有较好的鲁棒性,以及可根据局部流动状态和网格精度自动开闭的特点。

A novel turbulence wall layer model suitable for large eddy simulation using immersed boundary method is presented based on the hypothesis of constant shear stress in the near wall region.A slip velocity is introduced to modify the wall shear stress calculated using a linear velocity profile on the purpose of verifying the Werner-Wengle model.Results from the simulations of high-Re turbulent flow over a plate and in a pipe show that the velocity profile obtained using the wall layer model agrees well with the experimental data,which provides strong evidences of the good accuracy and fidelity of the method.Simulations with different relative positions of the Eulerian/Lagrangian grids were carried out and their influence on the accuracy was investigated.Robustness and the feature of switching on/off automatically according to the surrounding flow state and grid resolutions of the model were confirmed.