Characterization of a Jet Impingement Heat Sink for Power Electronics Cooling

Ongoing demand to improve power electronic converters in terms of efficiency, power density, reliability, cost and packaging calls for optimal thermal management. This paper investigates the effectiveness of a jet impingement heat sink consisting of an array of jets impinging discrete heat sources. A mixture of 60 – 40% (by volume) ethylene glycol – water is the coolant used. Through computational simulations and experimentation on a laboratory prototype, the heat transfer and pressure drop of the heat sink is characterized in terms of Reynolds number, Prandtl number, stand-off distance and jet-to-jet spacing. Correlations for area averaged Nusselt numbers and the Euler number are presented. A trade-off between heat transfer and pressure drop performance is further studied. Higher heat transfer rates were obtained with smaller stand-off distances and larger jet-to-jet spacings at the cost of higher pressure drop. Over the range of parameters tested, heat transfer was found to be more sensitive to design changes (maximum variation of 17.3%) compared to pressure drop (<1% variation). An optimal design will consist of a low stand-off distance as this will provide maximum convective heat transfer rates at the cost of minor pressure drop increases and will ensure the heat sink is compact. © 2022 Elsevier Ltd