An investigation of the influence of surface roughness, water quality and nozzle on spray cooling of Aluminum alloy 6082

The objective of this study to investigate the influence of thickness, roughness, water quality and the type of nozzle on the cooling of Aluminum 6082. In this analysis, aluminum plates having both smooth and rough surface with 3 mm, 5 mm and 10 mm were used. The plates were heated up to 500 degrees C. In these experimental analyses, distilled and tap water were used as a coolant with a constant volumetric flow rate (e.g. 1.2 L/min). Spray Nozzle 460.404 and Full Jet Nozzle 544.400 were used to investigate the cooling rate and 1D model was used to analyze the results. The results indicate that cooling rate is faster in the case of tap water due to salt deposition on the material. It was also observed that nucleate boiling was dominating due to the full-jet nozzle compared to spray nozzle because the full-jet nozzle does not support the formation of a vapor layer on the material. However, the spray nozzle covered more wetting front area as compared to the full-jet nozzle. Additionally, the large heat transfer rate for the rough metal surface was linked with the increase of metal surface area compared to the smooth surface. Experiments were repeated for full-jet and spray nozzle to verify the accuracy of the results.