Heat transfer behavior in a rotating aluminum foam heat sink with a circular impinging jet

This work experimentally studied heat transfer associated with an impinging jet onto a rotating heat sink. Air was used as the impinging coolant, and a square Al-foam heat sink was adopted. The variable parameters were the jet Reynolds number (Re), the relative nozzle-to-foam tip distance (C/d), the rotational Reynolds number (Re-r) and the relative side length of the square heat sink (L/d). The effects of Re, C/d, Re-r and L/d on the dimensionless temperature distributions and the average Nusselt number were considered. For a stationary system, the results reveal that the average Nusselt number (Nu(0)) with Al-foam was two to three times that without Al-foam. Nu(0) increased with Re. A larger L/d responded to a larger Nu(0) based on the same jet flow rate. The effect of C/d on Nu(0) was negligible herein. For a rotating system, when Re and L/d were small and C/d was large, the average Nusselt number (Nu(Omega)) increased considerably with Re,. Additionally, for Nu(Omega)/Nu(0) >= 1.1, the results suggest that rotation was substantial at Re-r/Re >= 1.13 when L/d = 4.615 with C/d = 0-5 and at Re-r/Re >= 1.07 when L/d = 3.0 with C/d = 0-5. For L/d = 2.222, rotation was substantial at Re-r/Re >= 1.44 when C/d = 0 and was always substantial when C/d >= 1. (C) 2007 Published by Elsevier Ltd.