Modular grad-div stabilization for the incompressible non-isothermal fluid flows

This paper considers a modular grad-div stabilization method for approximating solutions of the time-dependent Boussinesq model non-isothermal flows. The proposed adds minimally intrusive step to an existing code, with key idea being that penalization divergence errors, is only in extra (i.e. nothing added original equations). provides full mathematical analysis by proving unconditional stability and optimal convergence methods considered. Numerical experiments confirm theoretical findings, show algorithms have similar positive effect as usual stabilization.