Coupled level-set lattice Boltzmann method on adaptive Cartesian grids

A novel two-fluid coupled level-set lattice Boltzmann method on adaptive Cartesian grids for simulating liquid-gas multiphase flows is presented. The approach addresses the inherent challenges of accurately modeling multiphase systems characterized by sharp interfaces and large density ratios. In this method separate solution algorithms are used for each fluid phase, which are coupled through boundary conditions at the interface. We demonstrate the method’s ability to handle large density and viscosity ratios and enhanced efficiency compared to approaches utilizing a uniform solution method. The study highlights the advantages of using lattice Boltzmann methods combined with level-set techniques to efficiently track interfaces while facilitating adaptive mesh refinement on a joint hierarchical Cartesian mesh. Applications to various test cases, e.g., immiscible stratified flow and rising bubbles, demonstrate the method’s capability to accurately capture the dynamics of the interface and validate its accuracy by comparson with literature data.