Investigation of the effects of the dimension of a localized heat source on the natural convection in square cavities

摘要

The objective of the present study is to gain some insight into fluid motion and heat transfer phenomena in the case of a square enclosure heated from below and symmetrically cooled from the sides; the effects of different dimensions of the heat source are experimentally investigated. In this paper we analysed the effect of the variation in the heat source length on the natural convection inside the square cavity; the length of the heat sources studied are 1/5,2/5,3/5 and 4/5 of the wall. The temperature distribution is experimentally measured by real-time and double-exposure holographic interferometry. Different convection forms were obtained depending on Ra and on the heat source length. Graphs with relations between average Nu, Ra and the heat source length are finally presented. The Nusselt number was evaluated on the heat source surface and it showed a symmetrical form raising near the heat source borders.