Hybrid lattice Boltzmann finite difference simulation of Soret convection flows in a square cavity with internal heat generation

Abstract

Thermosolutal natural convection heat and mass transfer in a 2D square cavity are studied numerically in the presence of Soret effect and uniform volumetric heat generation. A hybrid scheme with simple relaxation time lattice Boltzmann method (SRT-LBM) is used to obtain the velocity field while the temperature and concentration fields are deduced from energy and species balances using a finite difference method (FDM). The study focuses on the effect of three parameters, which are the Soret parameter (, 0, and 0.5), the buoyancy ratio ( and 1), and the internal to external Rayleigh numbers ratio (). Combined effects of these parameters on fluid flow and heat and mass transfer characteristics are examined for Lewis number Le =2, Prandtl number , and external Rayleigh number . The interaction between the heat generation and the thermodiffusion may play an important role in purifying/charging the confined fluid from/with species by considering positive/negative values of .