ANNULAR HEAT TRANSFER ENHANCEMENT USING JET IMPINGEMENT

Heat transfer in annuli has been widely investigated over the years. Annular channels are found in multiple industry applications, ranging from electronic equipment to nuclear reactor cooling. In order to enhance heat transfer, internal passages are augmented with roughness elements such as dimples, pimples, ribs, fins, and other features. However, the use of impingement cooling mechanism has not been utilized for such annular channels. An experimental study of impingement cooling within an annulus with the outer surface of the annulus being heated uniformly is conducted. Multiple flows as a function of Jet Reynolds number in the range of 16,000 to 46,000 are fundamentally examined. An impingement sleeve with an annular ratio of 0.92 was experimentally tested and compared to RANS numerical simulation results. Temperature Sensitive Paint (TSP) was utilized to experimentally obtain the local Heat Transfer distribution along the annular wall and close channel cap, which is normalized by the baseline annulus heat transfer distribution. Heat transfer results for the annular surface is compared with available correlations. Pressure drop across the facility is characterized at the inlet and exit of the experimental set up.