An Improved Coupled Level Set and Continuous Moment-of-Fluid Method for Simulating Multiphase Flows with Phase Change

Abstract

An improved algorithm for computing multiphase flows is presented in which the multimaterial Moment-of-Fluid (MOF) algorithm for multiphase flows, initially described by Li et al. (2015), is enhanced addressing existing MOF difficulties in computing solutions to problems in which surface tension forces are crucial for understanding salient flow mechanisms. The Continuous MOF (CMOF) method is motivated in this article. The CMOF reconstruction method inherently removes the “checkerboard instability” that persists when using the MOF method on surface tension driven multiphase (multimaterial) flows. The CMOF reconstruction algorithm is accelerated by coupling the CMOF method to the level set method and coupling the CMOF method to a decision tree machine learning (ML) algorithm. Multiphase flow examples are shown in the two-dimensional (2D), three-dimensional (3D) axisymmetric “RZ”, and 3D coordinate systems. Examples include two material and three material multiphase flows: bubble formation, the impingement of a liquid jet on a gas bubble in a cryogenic fuel tank, freezing, and liquid lens dynamics.

Funding

National Aeronautics and Space Administration(80NSSC20K0352)