Heat transfer coefficients for a cup-like cavity rotating about its own axis

Heat transfer coefficients were determined experimentally for the cylindrical and base surfaces of a cup-like rotating cavity. The experiments encompassed three cavity length-diameter ratios and rotational Reynolds numbers which covered a fifteen-fold range. Two variants of the thermal boundary conditions were investigated. In one, both the cylindrical and base surfaces were thermally active, while in the other, heat transfer was confined to the cylindrical surface. The heat transfer coefficients for the cylindrical surface decrease with increasing cavity depth, the extent of the decrease being greater when there is no heat transfer at the base. The base-surface coefficients were found to be independent of cavity depth at the higher Reynolds numbers but decreased for deeper cavities at lower Reynolds numbers. In addition, at high Reynolds numbers, the base-surface coefficients were in excellent accord with those for an unshrouded rotating disk while at low Reynolds numbers they fell below the unshrouded-disk values. Excellent correlations of the data were achieved with power-law representations. Supplementary experiments involving a rotating disk showed that the accuracy of the data was in the 2-3% range or better.