Experimental study of natural convection heat transfer on an enclosure partially filled porous medium heated from below by constant heat flux

This study reports on natural convection heat transfer in a square enclosure of length (L=20 cm) with saturated porous medium (solid glass beads) having same fluid (air) at lower horizontal layer and free air fill the rest cavity's space. The experimental work has been performed under effects heating from bottom by constant flux q=150,300,450,600 W/m2 for four layers thickness Hp (2.5,5,7.5,1) cm three heaters δ (20,14,7) cm. top wall was good insulated two side walls were symmetrically cooled temperature. Four media small porosity, Rayleigh number range (60.354 - 241.41) (Da) 3.025x10−8 investigated. obtained data temperature testing rig are used to extract distribution, local Nusselt average number. Moreover, comparison between numerical result problem published recently present results executed discussed. It is evinced that; flow affected be maximum (0.25L) larger heater length(20cm) (q= 600 Watt/m2) which approximately (180%) Nu when compared (Hp=0.75L). Also, effect increasing (δ) averaged enhancement more pronounced large size 25% achieved (δ =20cm) =7cm). However, greater distribution found Hp=2.5cm 5cm first quarter cavity (heater surface height Y=0 Y=5 respectively minimum (insulation Y=20 cm). Nearly, shape different case clearly difference (δ=7cm).