Effect of injection parameters on jet array impingement heat transfer

The purpose of the present study is to clarify the heat transfer characteristics with multiple jet impingement aiming at the highly efficient cooling performance. In the study, we investigated the effect of injection parameters on circular jet array impingement heat transfer. As we focus on interference among the adjacent impinging jets, tests are mainly conducted at the minimum crossflow condition. The experiments are also conducted at injection distance from 2 to 8 jet hole diameters and jet-to-jet spacing from 4 to 8 jet hole diameters. Jet hole diameter Reynolds number is 4,680. Thermochromic liquid crystal is used to obtain heat transfer coefficient. Wall pressure measurement and oil flow visualization on the target surface are performed to understand the flow pattern of impinging jet and wall jet. The effect of injection parameters, such as injection distance, jet-to-jet spacing and number of jets, on jet array impingement heat transfer is clarified.