Cubic-Interpolated Pseudo-particle model to predict thermal behavior of a nanofluid

Abstract

Heat transfer behavior has been investigated for nanofluids in a two-dimensional square enclosure for different Grashof numbers and solid volume fractions. A numerical tool was designed to simulate the thermal fluid flow problem, which includes nanoparticles in a cubic interpolation profile. Nanofluid equations were applied to the stream-vorticity equations. The advection term was discretized by applying the Cubic-Interpolated Pseudo-particle (CIP) scheme with high precision. A model was then created to determine the heat transfer behavior in nanofluids. The nanofluid in the cavity contains silicon dioxide (SiO2) or aluminum oxide (Al2O3) in water. We studied the impacts of suspended ultrafine particles on the hydrodynamic and thermal characteristics of the processes. The results show that The lower heat transfer was obtained for Al2O3 due to domination of conduction mode of heat transfer since it has the lower value of thermal conductivity compared to SiO2. The thermal conductivity of Al2O3 is approximately 60% less than SiO2. The reduced value of thermal conductivity leads to lower temperature gradients and, therefore, lower enhancements in heat transfer. As volume fraction of nanoparticles increases, difference for mean Nusselt number between two nanoparticles becomes larger especially at higher Rayleigh numbers due to increasing of domination of convection mode of heat transfer. However, the difference in the values of Al2O3 and SiO2 is negligible since the behaviors of them are similar.