Double Diffusive Convection of Power Law Fluids Through Taylor–Couette Flow

Abstract

The proposed study focuses on the effect of double diffusive convection on the flow structures of power-law fluids between two coaxial cylinders of finite aspect ratios with end caps. We adopted a D2Q9 axisymmetric lattice Boltzmann model to predict the power-law fluid flow and D2Q4 (Lattice Boltzman method) model for azimuthal velocity, concentration, and the temperature. For ( is the solutal and thermal buoyancy forces ratio), fixed Taylor number with increasing Rayleigh number , the thermal base flow regime is more pronounced for the pseudoplastic fluid compared to the dilatant fluid. In addition, the thermal base flow in the annulus is delayed when increases. Thus, the increase of the behavior index has a stabilizing effect on the flow structure. On the other hand, when , the solute buoyancy forces in the annulus prevail over the centrifugal and thermal buoyancy forces, and the flow becomes ultimately a solute base flow for . For , the flow becomes a thermal base flow for . Thus, the mass transfer with negative values has a greater stabilizing effect on the flow structures than with positive .