Comparative CmFD Study on Geometric and Algebraic Coupled Level Set and Volume of Fluid Methods

Coupled Level Set and Volume Of Fluid (CLSVOF) method is an Eulerian interface capturing technique in Computational multi-Fluid Dynamic (CmFD) problems. It is broadly classified into geometric and algebraic types of method. A geometric CLSVOF method requires construction of a sharp interface, which is avoided in an algebraic method by considering a numerically diffused interface. Geometric methods are generally more accurate than algebraic methods; however, numerical implementation of algebraic CLSVOF schemes is relatively straightforward. This paper presents a relative performance of the two types of CLSVOF methods; geometric Piecewise Linear Interface Calculation (PLIC) and algebraic Weighted Line Interface Calculation-Tangent of the Hyperbola for INterface Capturing (WLIC-THINC); for gravity dominated dam-break problem and surface tension dominated buoyant rise of a bubble. Incompressible Navier–Stokes equations are solved on a co-located grid using a balanced-force method to avoid decoupling of pressure and interfacial forces. Both the types of CLSVOF method perform satisfactorily when there is a smooth change in the interface topology, demonstrated for the dam-break problem. However, when severe interface deformation occurs for the bubble rise problem, results show that the geometric-based method offers modestly better accuracy than algebraic methods owing to their sharp treatment of the interface.