MOF界面重构方法在超高速运动中的应用

Applications of the Moment-of-Fluid(MOF) method in hypervelocity motion

应用MFPPM(Multi-Fluid Parabolic Piecewise Method)方法进行超高速运动数值模拟时,由于其使用的PPM(Parabolic Piecewise Method)方法通常采用几个过渡网格来描述间断面,使得界面分辨率不高。为了更精确地对界面进行描述,将MOF(Moment-of-Fluid)界面重构方法与具有自主知识产权的MFPPM程序相结合,并首次将MOF方法运用到超高速运动中,对瞬时起爆的TNT炸药内聚压缩不同形状(三角形、正方形、正五边形、正六边形)的气腔进行了数值模拟;分别对四种构型在t=3?s和t=6.5?s时的VOF和MOF结果进行了对比。结果表明:MOF方法不仅能有效地捕捉到超高速运动中的构型几何特征,且在界面处不需要多个网格进行过渡,提高了界面重构的精度和分辨率。本文研究为界面不稳定性等问题中的复杂界面重构提供了一种新的方法。

Several meshes are needed to reconstruct the interface in the hypervelocity motions simulated by the MFPPM(Multi-Fluid Parabolic Piecewise Method) due to the use of model in the Parabolic Piecewise Method. In order to improve the accuracy of the reconstructed interface, the MOF(Moment-of-Fluid) interface reconstruction method is employed and combined with our MFPPM code to simulate the various cavities(such as the equilateral triangle, the square, and so on) compressed by the high pressure loading. Results at t=3s and t=6.5s indicate that MOF method is capable enough to capture the features of the configurations in the hypervelocity motion, and several meshes are no longer needed to reconstruct the interface of contact discontinuities. The MOF method improves the accuracy of reconstructed interfaces and reveals the potential to deal with the more complicated interfaces in instability problems.