MFCAV近似Riemann解在新型拉氏方法中的应用

THE PRACTICAL MFCAV RIEMANN SOLVER IS APPLIED TO A NEW CELL-CENTERED LAGRANGIAN METHOD

Maire等提出了一种新型的有限体积中心型拉氏方法,该方法大大地改善了一直困扰着一般中心型拉氏方法的虚假网格变形.然而在计算数值流和移动网格时,该方法只应用了数值黏性较大的弱波近似(weak waveapproximated method,WWAM)Riemann解,而且方法的设计表明其他类型的近似Riemann解不能简单直接地应用上去.将体平均多流管(multi fluid channel on averaged volume,MFCAV)近似Riemann解视为对WWAM的修正,成功将其应用于新型方法中,数值实验表明应用了MFCAV的新方法是有效的.研究为将其他更为有效的近似Riemann解应用于该新型方法中开辟了一条道路.

Recently, Maire et al. developed a new cell-centered finite-volume Lagrangian method, which greatly eases the problem of spurious grid deformations that have long been troubling cell-centered Lagrangian methods. However, the new method uses only the WWAM approximate Riemann solver in the computation of numerical fluxes, which has much numerical dissipation; moreover, the design of the new method indicates that approximate Riemann solvers in forms other than that of WWAM are not able to be straightforwardly applied to the method. This work successfully applies the MFCAV approximate Riemann solver to Maire et al＇s method by viewing the MFCAV as a modification of the WWAM. Our numerical tests show that the new method using the MFCAV solver is effective. This study opens a door for applications of Riemann solvers in forms other than that of WWAM to Maire et al＇s new Lagrangian method.