MHD Cattaneo–Christov Heat and Mass Fluxes with Nanofluid Flow in a Porous Medium between Dual Stretchable Rotating Disks

Abstract

Investigation of nanofluid flow, mass and heat transfer, and impact of thermal relaxation time parameter against temperature in porous spinning rotating stretching disks was done. The behavior of heat and mass transfer, velocity, temperature and particles concentration volume fraction profiles against other parameters are investigated. A decrease in heat transfer in the lower disk and upper disk was observed as Eckert number, porosity parameter and Brownian diffusion parameter increased in value though with an increase in temperature ratio and thermal relaxation time parameter. The mass transfer rate at both lower and upper disk increased as Lewis number, Eckert number alongside porosity parameter increase in values, but decreases in value as Brownian diffusion parameter and temperature ratio increase in values. Increasing thermal relaxation time parameter caused decrease in temperature. The physical meaning is that because longer time is needed for transporting heat to nearby particles, the upper disk stretching parameter increases whenever radial velocity profile towards the lower disk is increased, which was exhibited by a negative sign towards the lower disk and positive sign in the neighbourhood of the upper disk. This implies that the fluid inside the two disks continues to flow in opposite directions of upward and downward directions. The partial differential equations which are non-linear are, transformed to non-linear coupled ordinary differential equations by app-lying Van Karman transformations which are then solved using MATLAP bvp4c with shooting technique.