Numerical Investigation of the Impingement Cooling Characteristics of Sweeping Jets with Phase Change

Abstract

This study investigates the cooling features of sweeping jets with phase changes, providing insights into how parameters affect heat transfer. The study aims to improve heat transfer by investigating the cooling effects of a sweeping jet impinging on a concave wall. The Eulerian-Lagrangian particle tracking method was used to examine the impact of Reynolds number, droplet diameter, mist capacity, and impingement distance on heat transfer properties during the sweeping jet impingement cooling. Increasing the Reynolds number from 20,000 to 35,200 results in a 7.1% and 3.3% decrease in average temperature at the axial centerline of the impingement wall, attributed to the cooling effect from droplet phase change. Decreasing droplet diameter from 20 µm to 10 µm reduces temperature amplitude by 11K. At 5% and 7.5% mist ratios, the cooling performance is similar to that of dry air. However, a mist injection of 10% significantly amplifies the cooling effect by 18.8%, providing a more efficient cooling experience. This investigation provides essential perspectives on impingement cooling, offering insights into the impact of various parameters on heat transfer enhancement.