Experimental and Numerical Analyses of Multiple Jets Impingement Cooling for High-Power Electronics

Effective cooling of electronic equipment has emerged as a challenging and constraining problem of the 21st century. Jet impingement is a high-performance cooling technology for enhancing the heat transfer in thermal devices. This paper reports the experimental and numerical investigations carried out to study the heat transfer characteristics of multiple air jets impinging on a stationary flat copper plate. The software used for the numerical studies is a finite-volume-based software, ANSYS Fluent. An experimental setup was designed and fabricated. The results obtained from numerical studies were validated with that obtained from experimental studies. A copper plate, which is heated from the bottom, was used as the heat transfer surface of a simulated chip. The jets were produced by three sharp-edged circular orifices arranged in an in-line configuration. The nozzle-to-plate distance was varied as 1, 2, 4, 6, and 7 times the nozzle diameter (d). The effects of Reynolds number (4000-8000) and jet-to-jet spacing on heat transfer characteristics were examined numerically. From the studies, it was found that for a Reynolds number of 5000, optimum cooling is obtained when nozzle-to-plate spacing (H) is 6 times the orifice diameter. A correlation was proposed for Nusselt number in terms of Reynolds number, and it is valid for air as the cooling medium.