Natural Convection Heat Transfer of Metal Cuboids Flush Mounted in A Horizontal Plate

Abstract

The increased heat production per unit area in electronic equipment leads to a more critical heat balance. A more sophisticated and accurate way to calculate or measure the heat transfer from critical components to the local environment is needed. A lot of advanced computer packages exist for calculating the thermal behaviour of electronic equipment. If the heat transfer is strongly dependent on natural convection near horizontal surfaces, small changes in boundary or initial conditions could lead to significant differences in the calculated temperature- and velocity field (see Lasance [1]). The assumptions made in the calculation procedure or boundary conditions can lead to errors, that in the near future will not be within tolerable limits. Therefore an experimental apparatus is designed, that enables a better interpretation of numerical results corresponding to natural convection heat transfer near horizontal plates with discrete heat sources.

The experimental apparatus consists of a test cabinet, a specially designed test object and a temperature measurement and flow visualization technique. The experimental results are compared with numerical results, calculated with the finite volume package Flotherm from Flomerics. A parameter study is made in order to discuss the differences between the experimental and numerical results. After elimination of the important error sources, the overall agreement between experimental and numerical results is good.