Heat transfer and pressure drop in the roughened equilateral triangular duct

Experimental investigations were conducted to study the forced convection of fully developed turbulent flow in the horizontal equilateral triangular duct fabricated with different surface roughness pitch ratio (P/e) of 4, 8, and 16 on the one side wall only. The entire bottom wall of the duct was heated uniformly and the other surfaces were thermally insulated. To understand the mechanism of the heat transfer enhancement, measurements of heat transfer were done to investigate the contributive factor of heat transfer promotion, namely, the fin effect. Smooth triangular ducts were also tested for benchmark purposes. The results were compared with those of previous investigations for similarly configured channels, at which they were roughened by regularly spaced transverse ribs in the rectangular and circular channels, (C) 2002 Elsevier Science Ltd.