Natural Convection in a Vertical Rectangular Enclosure

In this paper an experimental work has been conducted to investigate the influence of heating the lower half and cooling the upper half of vertical surface of a rectangular enclosure on natural convection. The enclosure length is (100 cm) with a square cross section (10×10 cm). The tests are done for three mass flow rates (0, 0.003 and 0.03 kg/sec) and five heat fluxes (48, 187, 400, 706 and 1080 W/m2). The hottest region formed is observed at ( = 0.67) where the lowest Nux is found while the coldest region is observed at ( = 0.33) where the highest Nux is found. Increasing the water mass flow rate enhances the heat transfer. The same thing happens with increasing the heat flux. A correlation is found to relate Nu with Ra (Nu= 0.216 Ra1/4) for (4×105≤Ra≤4×106). Both the experimental results and the correlation found are compared with a previous work and fair agreement is found.