Numerical Studies On Non Newtonian Fluid Flow Through Pipe Using CFD

Abstract

A validated CFD model was used to show the impact on heat transfer of one-dimensional laminar non-isoviscous flow through pipe subjected to forced transverse vibration. Through transverse vibration, which produces the chaotic fluid motion and swirling effects adequate radial mixing across the tube can be achieved which leads to great addition in heat transfer. Thermal boundary layer is developed more quickly and thus temperature profile developed is wilder than steady flow under the effect of vibration in both radial and axial direction considerably for low Reynolds Number. These effects reduce significantly as the Reynolds number increases. In this study, these effects are quantitatively exhibited for Newtonians and shear-thinning fluids at various Reynolds number. It was found that application of superimposed vibrational flow limited considerably for low Reynolds number and for less shear-thinning property fluids. The effect of solid particle concentration and flow velocity of nanofluid with and without superimposed vibration were numerically investigated. For this purpose, non-newtonian nanofluid containing Al2O3 and aqueous CMC solution as a single phase with an average particle size of and particle concentration of and were used. Effects of volume concentration on the convective heat transfer coefficient were investigated in different Reynolds number for different vibration parameters (amplitude and frequency). The results showed that in a steady flow, with Reynolds number dispersion of nanoparticles causes the thermal boundary layer to grow rapidly than that of base fluid in axial direction and vibration act as a catalyst; at a given concentration much enhancement results than steady state. The ratio of convective heat transfer coefficient of unsteady-state to steady-state flow of nanofluid decreases with an increase of Reynolds number and increases with concentration. Vibration effects reduce in significance as frequency increases and these are more sensitive to amplitude than to frequency. The largest inc