Effect of Transverse Aspect Ratio and Distinct Ventilation Techniques on Convective Heat Transfer from a Rectangular Enclosure: Experimental and Numerical Study

Abstract

Our objective in this study was to investigate the convective heat transfer in a cavity with ventilation ports. The study has been divided into experimental and numerical sections and under the experimental study the enclosure considered with two exit ports at roof and one inlet opening with varying aspect ratio. Under the numerical study, the model validation is done at AR = 5, and then the study continued for one exit port each on the left side and right side. The enclosure is equipped with three discrete heat sources at the bottom wall and with an exhaust fan at the exit port. The ranges of parameters considered under experimental study as 1.25 ≤ AR ≤ 2.5, 3224 ≤ Re ≤ 6579, 8.5 × 106 ≤ Gr ≤ 1.03 × 108, and as a consequence Richardson number obtained in the range 0.21–9.58. Experimental results set out that the heat source surface Nusselt number decreases with an increase in aspect ratio however; at higher aspect ratio, the values of Nusselt number remain almost unchanged. The enclosure bulk fluid Nusselt number increases with an increase in aspect ratio. The study revealed that for a given aspect ratio with an increase in Re, the heat source Nu increases. The numerical study divulged that the ventilation port arrangement at the right side of enclosure exhibits the better thermal performance among all the three orientations considered and the results are supported with the streamline and temperature contours. The study of varying inlet port height disclosed that as the inlet port height is increased, the heater surface temperature drops and the enhanced heat transfer is achieved.