Forced convection in a fully-filled bidisperse porous annular duct subject to asymmetric heat fluxes

Abstract

• Heat transport in bidisperse porous annular duct is theoretically studied. • The bidispersivity triggers critical effective thermal conductivity ratio. • Nusselt number reaches the peak with a heat flux ratio of 0.175. • Wider range of high thermal performance appears by increasing the heat flux ratio. In the present work, convective heat transport through an annular duct fully filled with a bidisperse porous medium (BDPM) is analytically studied by using the two-velocity two-temperature model. The annulus is heated from inner and outer walls by asymmetric heat fluxes. Analytical solutions are deduced for the velocity and temperature distributions of f- and p-phases in the developed and laminar regime. The results show that the bidispersivity benefits the heat transfer enhancement in a lower range of effective thermal conductivity ratio compared to the monodisperse porous medium (MDPM). However, this advantage will vanish once the conductivity ratio exceeds its critical value. The BDPM annular duct having a peak average Nusselt number is found at the heat flux ratio equal to 0.175 under considered parameters.