一种新的边界处理方法在笛卡尔网格中的应用

采用自适应笛卡尔网格方法求解Euler方程,固壁边界条件通过一种离散强迫浸入边界方法引入,边界切割网格与流场网格保持一致,从而有效解决了小切割网格单元的时间步长限制问题.针对自适应笛卡尔网格的特点提出了新的虚拟点反射方法和插值方法,解决了数值吸力峰值问题.对RAE2822翼型、双NACA0012翼型和Suddhoo三元翼型的流动状况进行了无黏数值模拟,并与现有的理论解、单域以及分区结构网格解进行了对比.结果表明：该离散强迫浸入边界方法有效地引进了固壁边界条件,结合自适应笛卡尔网格技术能够准确模拟复杂几何外形下的流动状况.

Application of new boundary method in Cartesian-mesh

Adaptively-refined Cartesian-mesh approaches were employed for the computation of Euler equations,solid wall boundary was introduced by a discrete forcing immersed boundary approach,and shape of cut cell kept in accordance with that in the flow field,which efficiently relieved the time step restriction of small cut cell.To remedy the numerical suction peak,a novel method for reflection of ghost point along with interpolation scheme were devised which were applied for adaptively-refined Cartesian-mesh.Inviscid flows around RAE2822 airfoil,double NACA0012 airfoil and Suddhoo three-element airfoil were simulated and compared with published theoretical and single/multi domain structured mesh results.The results show that solid wall is efficiently resolved by the current discrete forcing immersed boundary approach and flows around complex geometries are adequately simulated by adaptively-refined Cartesian-mesh approaches.