Analysis of Vorticity Confinement for Compressible Flows

This paper presents an analysis of Vorticity Confinement when the compressible Euler equations are solved. Compared to the classical Vorticity Confinement approach, the addition of a source term for the mass-conservation equation is investigated, showing that it is possible to conserve a vortex in the computed flow-field endlessly. An analysis of the truncation error of the numerical solution shows that, in general, this Full Confinement procedure allows to decrease the truncation error at the vortex center, thus providing the capability to better conserve vorticity. Nevertheless, as shown when no regularization of the Vorticity Confinement term is applied, this is not the only mechanism involved in the confinement procedure, which is thus also powerful as a forcing term by itself.