A projection FEM for variable density incompressible flows

This work describes a new finite element projection method for the computat ion of incompressible viscous flows of nonuniform density, One original ide a of the proposed method consists in factorizing the density variable partl y outside and par-try inside the time evolution operator in the momentum eq uation, to prevent spatial discretization errors in the mass conservation t o affect the kinetic energy balance of the fluid. It is shown that uncondit ional stability in the incremental Version of the projection method is poss ible provided two projections are performed per time step. In particular, a second order accurate BDF projection method is presented and its numerical performance is illustrated by test computations and comparisons. (C) 2000 Academic Press.