The effect of drainage configuration on heat transfer under an impinging liquid jet array

The heat transfer characteristics of single and dual-exit drainage configur ations for arrays of liquid jets impinging normal to a heated isoflux plate has been studied experimentally. The interaction of drainage channel cross flow from upstream jets and the stagnation jets and its impact on heat tran sfer was the focus of the investigation. Infrared thermography was used to measure the local temperature distribution on the healed plate, from which local hear transfer coefficients were determined. A single jet diameter was used, and jet arrays with jet-to-jet spacings of 4.8, 6, 8, and 12 jet dia meters were studied. Average jet Reynolds numbers in the range 400-5000 wer e investigated for jet nozzle to-impingement plate spacings of 1, 2, and 4 jet diameters for fully flooded (submerged) drainage flow. A single jet-to- plate spacing large enough to yield free-surface jets was also studied. The data reveal a complex dependence of focal and average Nusselt numbers on t he geometric parameters which describe the problem configuration.