Augmentation of turbulent heat transfer on a flat plate with a three-dimensional protuberance. I - Local heat transfer characteristics and flow pattern around a finite length circular proturberance

In order to obtain the fundamental data on the high performance roughened heating surface, the augmentative effects of a three-dimensional protuberance, whose height was the same order as boundary layer thickness, was investigated. In this paper, the local heat transfer characteristics and flow field around a single and finite length circular cylindrical protuberance have been investigated experimentally, under the condition of H/D = 0.5 to about 1.0, H/to about = 5 Theta 15, and Re(H) 5000 to about 30000. Consequently, the most effective shape parameter for the augmentation of heat transfer was indicated, and a wake flow structure was proposed. And an arrangement of maximum heat transfer coefficient was presented experimentally as a function of shape parameter.