Experimental study of the effect of oil-based nanofluid on heat transfer characteristics in different arrangements of wavy microchannels

Abstract

The development of microchannel manufacturing technology has led to a growing interest in using them as heat exchangers. Microchannels are used to control the temperature of equipment and components that generate a high amount of heat flux. Heat transfer can be further increased by dispersing particles (nano-sized particles) with a low volume fraction into the base fluid (nanofluid). A nanofluid can change the thermophysical properties of a base fluid and improve its thermal performance. The purpose of this study was to examine the heat transfer characteristics of oil-based nanofluid within wavy microchannels in series and parallel arrangements of microchannels. In order to examine the performance of each microchannel separately and to make it easier to draw their diagrams, they are named 1 and 2. Experiments were performed on TiO2 and SiO2 oil-based nanofluids in volume fractions of 0.05 and 0.1, flow rates of 0.5, 1.0, and 1.5 lit/min, and inlet temperatures of 40°C, 45°C, 50°C, 55°C. The results show an increase in the Nusselt number of the base fluid up to 41.8% in the series arrangement and also a decrease in the surface temperature in the series arrangement compared to the parallel arrangement. Also, TiO2 and SiO2 nanofluids with a volume fraction of 0.1 caused the highest increase in heat transfer, up to 56% and 52.7% in parallel arrangement and up to 45.8% and 42% in series arrangement compared to the base fluid, respectively. The pressure drop of the test section in series arrangement was up to 82.1% higher than parallel.

Keywords

• microchannel
• oil-based nanofluid
• convective heat transfer
• nusselt number
• laminar flow
• pressure drop