Heat transfer properties of nanoparticles and the enhanced performance of a multiphase fluid

Abstract

Heat transfer is one of the most important fields in modern day engineering. In the last few decades, the field of heat transfer has gained a major research topic in the form of nanofluid. Traditional heat exchanger fluids have poor thermal conductivity whereas some solid particles have high thermal conductivity. Therefore the prospect of formulating a mixture of two materials in different phases has been in motion for some time. These fluids carrying nanoparticles are called nanofluids. They enhance the heat transfer rate significantly due to the higher specific surface area created by the nanometer sized particles. In this study, we simulate the heat transfer characteristics of 𝐴𝑙2𝑂3/water nanofluids in a simple heat exchanger under laminar flow condition. In our case, we varied the concentration of nanoparticles in the base fluid to observe the change of several properties of the multiphase fluid simultaneously. The effects of Nusselt number, thermal conductivity, viscosity and particle type on the heat transfer characteristics were investigated. Based on the results, further nanoparticles were added to the base fluid to significantly enhance the heat transfer characteristics. The data accumulated by this process helps us to predict the behavior of a multiphase fluid with known concentration of nanoparticles. It also creates an opportunity for us to modify the fluid properties accordingly by varying necessary variables like particle concentration, particle size etc