A level set formulation for incompressible two-phase flows on nonorthogonal grids

A level set (LS) formulation is presented for computing two-phase flows on nonorthogonal grids. Compared with the volume-of-fluid (VOF) method based on a nonsmooth volume-fraction function, the LS method can calculate an interface curvature more accurately by using a smooth distance function. It is also more straightforward to implement for two- and three-dimensional irregular meshes than the VOF method, which requires much more complicated geometric calculations. The LS formulation on nonorthogonal grids is verified through computations of free-surface motions in two and three dimensions. Also, an efficient formulation for contact angle modeling is incorporated into the LS method to simulate droplet motion on an inclined wall.