Numerical studies on convective mass transfer augmentation in high-speed flows with lateral sweep vortex generator and dimple cavity

Abstract

A numerical study on convective mass transfer enhancement by a lateral sweep vortex generator (LSVG)-dimple combination is presented. Surface features that can generate secondary flow structures are widely used for overcoming the difficulties in the transport process encountered in high-speed flows. Unsteady, three dimensional, turbulent fluid flow and mass transfer has been simulated using an Advection Upstream Splitting Method (AUSM) based finite volume solver. An improvised Temperature-Dependent Mass Efflux (TDME) condition is invoked to simulate mass evolution from a liquefying boundary as a function of adjoining fluid temperature. The computational procedure has been validated using experimental data of heat transfer coefficients obtained for a similar vortex generator. Extensive numerical simulations have been performed for various geometry and flow conditions to analyze the nature of the evolution of secondary flow structures and their role in promotion of mass advection. Q-Criterion estimates have been used for identifying regions of intense vortex fluid motion and its role in the promotion of mass transfer. The present vortex generator dimple combination can enhance mass transfer for a wider expanse of the domain. Correlations for the estimation of spatiotemporal convective mass transfer effects have also been derived from unsteady numerical computations.