Heat transfer on a rotating cylinder in a restricted flow with narrow spaces by two walls

Abstract

The local heat transfer on a rotating cylinder was measured by Mach-Zehnder interferometer. The rotating cylinder was set in a restricted flow with narrow spaces by two horizontal plates. The two plates were made by copper or polycarbonate. The heat transfer was measured about both clockwise direction and counterclockwise direction. We observed flow pattern near the cylinder by smoke. Rotating Reynolds numbers were varied from 0 to 3000 and cross-flow Reynolds numbers were varied from 0 to 2000. The spaces between cylinder and plates were varied from 1 x 10-3m to 5 x 10-3m. The following results are obtained: When the spaces between rotating cylinder and flat plates are same as the displacement thickness on the plates, the heat transfer on the cylinder has best performance. The distributions of local Nusselt number were different from each other cases, however average Nusselt numbers were same values for the comparisons of the cylinder rotations and the plate materials. We have obtained empirical equation of heat transfer from the rotating cylinder with narrow spaces by two plates.

Keywords

• heat transfer
• heat transfer enhancement
• rotating cylinder
• restricted flow
• flow visualization
• thermal visualization
• natural convection
• forced convection