Heat Transfer Study on Multiple Walls of an Impingement Channel With Variable Jet Heights

The present work studies the relationship between target and sidewall surfaces of a single row impingement channel at various jet-to-target distances. Temperature sensitive paint and constant flux heaters are used to gather heat transfer data on the target and side walls. Jet-to-target distance is set to 1, 2, 3, 5, 7 and 9 jet diameters. The spanwise jet spacing is 4 jet diameters and the streamwise jet spacing is 5 jet diameters. All cases were run at average jet Reynolds numbers ranging from 5,000 to 30,000. Pressure data is also gathered and used to calculate the channels mass flux profiles, used to better understand the flow characteristics of the impingement channel. While target plate heat transfer profiles have been thoroughly studied in the literature, side wall data has only recently begun to be studied. The present work shows the significant impact the side walls provide to the overall heat transfer capabilities of the impingement channel. When only the target wall heat transfer is considered, the Z/D = 2 channel performs the best; however, it was found that, when both the target and side wall channels were taken into account, the Z/D = 3 channel provides with the largest overall heat transfer rate through the target wall and the side walls out of all channel heights.