THE EFFECT OF FILM COOLING ON THE HEAT TRANSFER BETWEEN A SHROUDED ROTATING DISK AND A RADIALLY INWARD FLOW

A study of the cooling effect of a film stream on the heat transfer between a shrouded rotating disk and radially inward main flow stream is presented. The investigation is intended as a model study of the film cooled radial flow gas turbine. Film heating and film cooling are shown to be similar problems described by the same set of equations when property variations can be neglected. Experimental results were obtained from a film heated, rotating disk facility. These results were obtained over the range of radial flow gas turbine operating conditions. The heat transfer behavior of the main stream only was determined separately, and the film cooling results are presented as ratios of the heat transfer obtained with film cooling to the heat transfer obtained with only a single radial inflow. An analysis of the heat transfer to a film cooled, uniform temperature flat plate is presented. This analysis predicts the form but not the magnitude of the results obtained on the rotating disk.