HEAT-TRANSFER ENHANCEMENT IN A SERPENTINE CHANNEL

Forced-convection heat transfer rates and pressure drops were measured in the thermally fully developed region of a serpentine channel over Reynolds numbers ranging from 250 to 10000. The wall geometry was simi lar to # 17.8-3/8W of Kays and London [Compact Heat Exchangers (3rd Ed n). p. 204. McGraw-Hill, New York (1984)], but carefully designed to m inimize the extent of flow separation. The spatially-periodic wall imp ingement currents and high shear stresses combined to make a more unif orm streamwise variation in local heat flux compared with corrugated s urfaces. On an equal-Re basis. the heated surface of the serpentine ch annel outperformed the baseline parallel-plate channel by about a fact or of 9 in air and 14 in water. Thus wavy-walled channels may prove ef fective for enhancing heat transfer in laminar and transitional flow r egimes.