NUMERICAL SIMULATION OF THE TRANSPORT OF VORTEX RINGS IN AN INITIALLY STRATIFIED FLUID

A numerical study of the formation and transport of vortex rings in a cylindrical tank initially occupied by a thermally stratified fluid is presented. A control-volume based finite-difference technique (Patankar's SIMPLER method) is used. The formation of a vortex ring was simulated by injecting a quantity of a fluid through a tube centrally located near the free surface. Initially, the fluid in the tank was stably thermally stratified, with a low density in the upper half and higher density in the lower half. Buoyancy effects were considered. Modelling aspects are discussed and the formation and transport of a vortex ring in the stratified fluid as well as the resulting mixing characteristics are presented.