修正模板改进的五阶WENO-Z+格式
Improved Fifth-order WENO-Z+ Schemes Based on Modified Stencil
-
摘要: 介绍一种修正模板近似方法, 即改进经典五阶WENO-JS格式中各候选子模板上数值通量的二阶多项式逼近, 通过加入三次修正项使模板逼近达到四阶精度, 并且通过引入可调函数使其具有ENO性质。将这种修正模板近似方法运用到WENO-Z+和WENO-Z+M格式中, 发展基于修正模板类型的WENO-Z+格式(WENO-MS-Z+, WENO-MS-Z+M)。通过数值算例对格式进行数值测试, 结果显示: 该格式具有强健的激波捕捉能力和对小尺度波结构的高分辨率, 与原WENO-Z+和WENO-Z+M格式相比改进明显。Abstract: First, a modified stencil approximation method is introduced, which improves the second-order polynomial approximation of the numerical flux on each candidate sub-stencil in the classical fifth-order WENO-JS scheme. The stencil approximation reaches the fourth-order accuracy by adding a cubic correction term, and it has ENO property by introducing an adjustable function.Then the modified stencil approximation method is applied to WENO-Z+and WENO-Z+M schemes, and the modified WENO-Z+schemes based on the modified stencil type (WENO-MS-Z+, WENO-MS-Z+M) are developed.A series of numerical examples are used to test the new schemes. The results show that the new schemes have a strong ability to capture shock waves and high resolution for small-scale wave structures, which is significantly improved compared with the original WENO-Z+and WENO-Z+M schemes.