Heat transfer and pressure drop characteristics of mini-fin structures

Forced convection heat transfer of air and water in bronze and pure copper mini-fin structures and mini-channel structures was investigated experimentally. The mini-fin dimensions were 0.7 mm x 0.2 mm, and 0.8 mm x 0.4 mm. The tests included both staggered diamond-shaped and in-line square mini-fin arrangements. The tests investigated the effects of structures, mini-fin dimensions and arrangement, test section materials, and fluid properties on the convection heat transfer and heat transfer enhancement. For the tested conditions, the convection heat transfer coefficient was increased 9-21 fold for water and 12-38 fold for air in the mini-fin structures compared with an empty plate channel. The friction factor and flow resistance in the mini-channel structures and the in-line square mini-fin arrangement were much less than in the staggered diamond-shaped mini-fin arrangement. For the small channel width, W-c = 0.2 turn, the convection heat transfer with the in-line square array structure was more intense than with the staggered diamond-shaped structure, the mini-channel structure or the porous media. For the larger channel width, W-c = 0.4 mm, the convection heat transfer in the staggered diamond-shaped array structure was more intense than in the others systems while the in-line square structure had the best overall thermal-hydraulic performance. (c) 2006 Elsevier Inc. All rights reserved.