Pressure stabilization of finite element approximations of time-dependent incompressible flow problems

In this paper we develop and analyze pressure stabilized, finite element methods for the solution of the transient Stokes problem, which is a linear model problem of transient incompressible flow. A model for the bubble enrichment is proposed to stabilize the numerical solution and an implicit backward Euler method is considered for the time approximation. Different methods are obtained depending on whether bubbles are allowed to evolve with time or they are considered quasi-static. Stability estimates are provided for the two methods considered, both for the velocity and the pressure solutions. Numerical results obtained on test cases are also given, which confirm the theoretical stability results.