非定常自由面流动模拟的反扩散VOF算法研究  

Anti-diffusion VOF method for unsteady free-surface flow simulation

作　　者：李晓东 吴乘胜[1,2] 王星 王建春[1,2] 张亚英 LI Xiao-dong;WU Cheng-sheng;WANG Xing;WANG Jian-chun;ZHANG Ya-ying(China Ship Scientific Research Center,Wuxi 214082 China;Wuxi Orient Software Technology Co.Ltd.,Wuxi 214082,China)

机构地区：[1]中国船舶科学研究中心,江苏无锡214082 [2]中船重工奥蓝托无锡软件技术有限公司,江苏无锡214082

出　　处：《船舶力学》2024年第5期663-675,共13页Journal of Ship Mechanics

基　　金：水动力学重点实验室基金项目(k6971)。

摘　　要：VOF(Volume of Fluid)方法由于其良好的守恒性和网格适应性,且具有计算资源需求相对较小等优点,成为船舶水动力学领域自由面流动CFD(Computational Fluid Dynamics)模拟的主流方法。但原始的VOF方法存在较为严重的界面扩散问题,导致模拟的界面厚度过大、空间分辨率不够,进而影响流场相关变量的计算精度,这一问题在非定常自由面流动模拟中尤为明显。本文针对上述问题,通过在VOF控制方程中引入人工对流项以达到抑制界面扩散、压缩界面厚度的目的,并采用隐式离散人工对流项的方式提高计算稳定性,形成了反扩散VOF算法。经Zalesak和剪切场等经典算例在不同数量网格下的测试验证,表明反扩散VOF算法能够大幅压缩界面厚度,同时明显减小质量误差。随后的三维无障碍溃坝算例和破舱进水算例,进一步证明了反扩散VOF算法在实际非定常流动模拟中能够更好地捕捉自由面并提高计算精度。Because of the advantages of good physical conservation and grid suitability along with low de⁃mand on computational consumption,VOF is now the main numerical method for the treatment of free-sur⁃face in ship hydrodynamics.But for the original VOF method,the problem of interface diffusion is rather seri⁃ous and results in excessive thickness and insufficient resolution for interface simulation.It will also affect the computational precision of other correlative variables in the flow filed.This problem is especially serious in the simulation of unsteady free-surface flow.In this paper,anti-diffusion VOF method was developed by introducing an artificial convective term into the control equation to restrain interface diffusion and reduce in⁃terface thickness.Implicit scheme was adopted for discretization of the artificial convective term to ensure computational stability.The method was tested by typical cases of Zalesak and shear field under different meshes.The results show that the interface thickness is reduced remarkably and the mass error is also re⁃duced obviously.The simulations of 3-dimensional test cases for dam break and flooding in damaged cabin show that the anti-diffusion VOF method can capture the free-surface better and improve computational pre⁃cision in the CFD simulation of practical unsteady free-surface flow.

关 键 词：自由面 VOF方法 人工对流项 反扩散 

分 类 号：O359.1[理学—流体力学]