Heat Transfer Enhancement in Duct with Blunt Body Inserted Close to Its Wall

This paper shows the effects of clearance length between a body and a duct wall, and duct height on the heat transfer characteristics and flow behavior at downstream region of the body when a blunt body was set in a parallel plate duct with some distance separating it from the duct wall as a turbulence promoter. At the ratio of clearance length to body height, C/D= 0.05-0.1, the heat transfer was characterized by the reattachment of shear flow separated from the body. Furthermore, the heat transfer depended on both the reattachment flow and the separation vortex at C/D= 0.15-0.2, and the side vortex induced by Karman vortex at C/D = 0.25 and 0.275. The reattachment flow gives a superior effect to enhance heat transfer at low Reynolds number, but at larger Reynolds number, the side vortex induced by Karman vortex becomes more effective to heat transfer enhancement.