Experimental study of forced convection in asymmetrically heated sintered porous channels with/without periodic baffles

Abstract

This study experimentally determined the local and average heat transfer characteristics in asymmetrically heated sintered porous channels with metallic baffles. The fluid medium was air. Measurements on the test specimen of four modes, without baffles (A), with periodic baffles on the top portion (B), with periodic baffles on the bottom portion (C) and with staggered periodic baffles on both sides (D), are performed. The effect of the average bead diameter was also examined ( d = 0.704 and 1.163 mm). The data indicated that, the wall temperatures measured at baffles attached to the heated wall were slightly lower than those nearby, especially at high Reynolds numbers. In modes B and D, the heat transfer in the inlet region was weaker than that in modes A and C. Additionally, the heat transfer by forced convection in all modes increased as the bead diameter decreased. The effect of the bead diameter became stronger as the Reynolds number was increased. At Re > 2000, heat transfer was greatest in mode B and least in mode D, in which the heat transfer was even poorer than that without baffles. For a Re of around 1000, mode D was associated with an excellent heat transfer. In such a case, heat transfer enhancement was around 20 ∼ 30% in mode D, around 10 ∼ 20% in mode B and around 0 ∼ 12% in mode C.