Resonance of Natural Convection Inside a Bidisperse Porous Medium Enclosure

Schematic of enclosure with 4×4 porous block array (a) geometry, (b) mesh, and (c) pulsating heat flux

The response of instantaneous average Nuc, Num, and θ¯h for a BDPM enclosure at DaI→∞ (the clear fluid limit) and Ra=108 with different heat input frequencies: (a) 0.01, (b) 0.029, and (c) 0.04

The response of instantaneous average Nuc, Num, and θ¯h for a BDPM enclosure at N2=4×4, DaI=10−3, and Ra=108 with different heat input frequencies: (a) 0.01, (b) 0.02, and (c) 0.04

The response of instantaneous average Nuc, Num, and θ¯h for a BDPM enclosure at N2=4×4, DaI→0 (monodisperse limit), and Ra=108 with different heat input frequencies: (a) 0.01, (b) 0.02, and (c) 0.04

Instantaneous volume averaged velocity variation with average hot wall temperature at Ra=108 and f=fr for enclosure with (a) clear fluid, (b) porous blocks (4×4, DaI=10−3), and (c) solid blocks (4×4)

Instantaneous streamlines and isotherms for a BDPM enclosure for DaI→∞ (clear fluid limit) at Ra=108 and resonance frequency fr=0.029

Instantaneous streamlines and isotherms for a BDPM enclosure at N2=4×4, DaI=10−3, ϕE=0.64, and ϕI=0.5 at Ra=108 and resonance frequency fr=0.02

Instantaneous streamlines and isotherms for a BDPM enclosure at N2=4×4, DaI→0 (monodisperse limit), ϕE=0.64 at Ra=108, and resonance frequency fr=0.01

BDPM enclosure Num,max variation with pulsating heat input frequency in the steady oscillatory state for several DaI values at N2=4×4, ϕE=0.64, and Pr=0.7: (a) Ra=108 and (b) Ra=107

Effect of bidispersion (DaI) on the resonance (heating) frequency (fr) for Pr=0.7, N2=4×4, ϕE=0.64, and ϕI=0.5. Comparison of predictions from scale analysis and numerical method.

Effect of bidispersion (by varying ϕE) on the BDPM enclosure Num,max in the steady oscillatory state at N2=4×4, Ra=108, and Pr=0.7