Heat Transfer of a Metal Foamed Flat Plate Impinged by Multiple Jets

Abstract

The present study focuses on the measurement of the local heat transfer distribution of a smooth flat plate, a flat plate with attached metal foam, and detached metal foam under an inline array of multiple jets using thermal imaging and the thin metal foil technique. After impingement, jet flow exits from all directions. The range of the Reynolds numbers covered in the study is 2500 to 15,000. The impinging distance of to is studied. A 4-mm-thick aluminum metal foam having 92% porosity and 20-pore-per-inch pore density is used. The contribution of the convection and conduction heat for a flat plate with metal foam is studied using a flat plate with a detached foam configuration. The effect of the impinging distance and Reynolds number on the local, spanwise-averaged, and overall averaged Nusselt numbers is studied. The presence of the 4 mm metal foam enhances the local heat transfer in comparison with a smooth flat plate due to conduction heat transfer without the addition of extra hydraulic resistance to the jet flow. The enhancement of the heat transfer due to the presence of the metal foam is quantified by the enhancement factor , and it is found to be around 1.6.