Heat Transfer and Friction Characteristics in Rectangular Channel having Inclined and Transverse Ribs on the Absorber Plate

摘要

Experiments were conducted to study the heat transfer coefficient and friction factor for fully developed flow of air in a rectangular channel with compound rib roughness on absorber surface. The inclined discrete ribs and transverse full ribs were arranged in alternative rows. The angle of attack (a) for discrete and full ribs were kept at 60° and 90°, respectively. A comparison of fully developed heat transfer and friction factor characteristic were made in rectangular channel roughened with three rib configurations. Results were obtained for relative roughness height (e/D{sub}h) of 0.03, aspect ratio (W/H) of 10, relative roughness pitch between discrete and full ribs (p/e) of 8, 6 and 3. The experiments were conducted for Reynolds numberranging from 1500 to 13000. Results show that the heat transfer coefficient was maximum for relative roughness pitch of 8 and it was also been observed that friction factor was minimum for the same.