A HIGH-ORDER PROJECTION METHOD FOR TRACKING FLUID INTERFACES IN VARIABLE-DENSITY INCOMPRESSIBLE FLOWS

We present a numerical method for computing solutions of the incompres sible Euler or Navier-Stokes equations when a principal feature of the flow is the presence of an interface between two fluids with differen t fluid properties. The method is based on a second-order projection m ethod for variable density flows using an ''approximate projection'' f ormulation. The boundary between the fluids is tracked with a second-o rder, volume-of-fluid interface tracking algorithm. We present results for viscious Rayleigh-Taylor problems at early time with equal and un equal viscosities to demonstrate the convergence of the algorithm. We also present computational results for the Rayleigh-Taylor instability in air-helium and for bubbles and drops in an air-water system withou t surface tension to demonstrate the behavior of the algorithm on prob lems with large density and viscosity contrasts. (C) 1997 Academic Pre ss.