Natural convection air cooling characteristics of plate fins in a ventilated electronic cabinet

The aim of the present work is to evaluate natural convection air cooling characteristics of compact vertical rectangular plate fin arrays placed in a ventilated electronic cabinet. The present work focuses on plate fin arrays applicable to notebook personal computers and engineering workstations. Three-dimensional laminar flow analyses using the finite volume method were performed in order to evaluate the natural air cooling characteristics of vertical rectangular plate fin arrays located in a ventilated electronic cabinet with cooling air inlet and exit. The governing equations are the continuity, momentum, and energy equations with buoyancy term using Boussinesq approximation. The equations were solved using the SIMPLE scheme. Calculations were carried out for the plate spacing S=3, 4, 5 mm, the fin height H=20, 30, 40 mm, the cooling air inlet and exit height B=2.5, 5, 10 mm, and the fin length L=10 mm. Numerical results indicated that the average heat transfer coefficient of the fin exhibits an increasing trend with the increase of both the plate spacing S and the cooling air inlet and exit height B and that the average heat transfer coefficient of the fin base is about one order of magnitude less than that of the fin surface. Results also showed that in the case of the fin length equal to the air inlet height, the average heat transfer coefficient of the fin is almost equal to that of natural convection in a vertical rectangular channel. Additionally, based on the numerical results, some empirical equations for the average Nusselt number of vertical rectangular plate fin arrays located in a ventilated electronic cabinet with cooling air inlet and exit are proposed as a function of Ra-s*.