Use of Nanofluids for Improved Natural Cooling of Discretely Heated Cavities

Abstract

The present study is aimed at investigating the natural convection heat transfer from discrete heat sources to nanofluids. The behavior of nanofluids was investigated numerically inside a heated cavity to gain insight into convective recirculation and flow processes induced by a nanofluid. A computational model was developed to analyze heat transfer performance of nanofluids inside a cavity taking into account the solid particle dispersion. The model was validated through the comparison with available experimental data, and the results showed good agreement. The influence of the solid volume fraction and the aspect ratios on the flow pattern and heat transfer inside the cavity was investigated. The results show that the intensity of the streamlines increases with the volume fraction. The influence of the loading factor is more distinguished in the vicinity of the upper heaters and, in particular, at the highest heater. The heat transfer increases with the increase in the volume fraction of the nanoparticles in the range of 2 to 10%. As the aspect ratio (AR) increases (channel width is reduced), the streamlines change and the intensity of the streamlines increases slightly, showing flow in the middle of the channel. The stagnation region disappears, and interaction between the two boundary layers at the hot and cold walls is evident.

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