多介质流界面高精度自适应欧拉算法

High Resolution Eulerian Adaptive Algorithm for Multi-fluid Interfaces

采用欧拉网格自适应算法捕捉多介质流界面,获得了高精度界面特征,对不同物质引入不同位标函数跟踪界面运动,将位标函数方程与流体动力学方程非耦合求解,在笛卡尔坐标系中运用二阶精度有限体积算法,在保持流场守恒条件下,采用多层网格级对笛卡尔网格嵌套细化,实现了多介质流物质界面的高精度自适应跟踪.方法逻辑简单,大大节省了CPU时间,且能够对局部参数急剧变化的流场(如激波)进行自适应跟踪.

Level Set (LS) function for tracking multi\|fluid interfaces and the different materials corresponding to different leves are applied.These LS equations together with fluid dynamic Euler equations are solved independently.An adaptive mesh refinement (AMR) method in the context of Cartesian grids is discussed at the same time.Such an approach can be automatically adaptive in that it chooses the regions of refinement based on the behavior of the solution while for time dependent problems the regions of refinement must change with time.There are two main strategies that have been used to handle the data structures involved when a rectangular grid is being refined.One approach is to refine individual grid cells as needed,typically by splitting a single cell in two dimensions into four pieces.Each of these pieces may be further subdivided recursively,depending on how many levels of refinement are allowed.High resolution results can be given by using this method,and it can also track the shock front adaptively and save CPU greatly.