Abstract
A new version of the TUMMAC method is developed so that it may cope with two-layer flows involving strongly interacting interface. A new treatment of the free-surface conditions is devised and introduced into the MAC-type finite-difference simulation method which is based on the Navier-Stokes equations approximated in the rectangular mesh system. The applicability of the method is demonstrated by two test simulations, i. e., the simulation of 3D breaking waves about a vertical cylinder piercing the air-water interface, and the simulation of the effect of water flow on the motion of sand layer beneath it.
