Effects of inner rotating horizontal cylinder on heat transfer in a differentially heated enclosure

摘要

The effects of inner rotating horizontal cylinder on the heat transfer in a differentially heated enclosure were investigated experimentally. The aspect ratio of the enclosure height/width was 1 throughout the experiments. A bakelite cylinder was installed horizontally at the center of the square enclosure, and was rotated at various speeds. Purified water was used for the working fluid. The surface temperature of the rotating cylinder was measured using a telemetry system, and the flow pattern was sketched by a visualization experiment using aluminum powder. It is clarified here that the rotating cylinder suppresses the heat transfer rate of the enclosure in the low rotating speed range because of the interference between natural and forced convections. However, marked heat transfer enhancement can be obtained in the high rotating speed range. The rotating cylinder used here is useful for regulation of wide-ranging heat transfer rate.