曲率相关的爆轰波在非结构四边形网格上的数值方法

Numerical Schemes for Detonation Front on Curvature on Unstructured Quadrilateral Meshes

假设爆轰波阵面的法向速度是曲率的线性函数,在非结构四边形网格上采用水平集方法模拟爆轰波阵面的运动过程.水平集方程的曲率无关项采用正格式离散,曲率项采用伽辽金等参有限元方法空间离散,时间离散采用半隐格式.在笛卡儿网格和随机网格上,含曲率的水平集方程的离散格式为强一阶精度,重新初始化方程的离散格式精度为近似一阶精度.曲率收缩的不光滑界面和多个爆轰波阵面相互作用的算例说明格式可有效地模拟爆轰波与曲率相关的运动.

Assuming that detonation normal velocity is a linear function of curvature,we study propagation of detonation front on unstructured quadrilaterals with level set method.Convection term in leve set equation is solved by positive scheme,and curvature term is solved by Galerkin isoparametric finite element method and semi-implicit time stepping.On Cartesian meshes and random meshes,the scheme of level set equations containing curvature is more than first order accuracy in L2 and L∝ norms.Examples of nonsmooth level sets shortening and three detonation fronts colliding show that the schemes can be used to simulate propagation of detonation front on curvature.