Effect of property variation on the fluid flow and thermal behavior in a vertical channel

Abstract

Natural convection in a vertical fin array is studied numerically for Non-Boussinesq and Boussinesq fluid with the effect of property variations. Simulations are carried out for the specified range: non-dimensional fin spacing = 0.2 to 0.5, non-dimensional clearance = 0.05 to 0.4 and Grashof number = 1.86 × 105 to 8.64 × 105. Computations are executed to plot the isotherms contours across the section close to the outlet to exemplify the effect of non-Boussinesq fluid in natural convection for variable properties. Computation demonstrates a maximum of 9% higher overall Nu for fixed property Boussinesq fluid than compared to the non-Boussinesq fluid. And for the Boussinesq fluid with the thermo-physical property maintained constant, the results obtained for local Nusselt number is consistently higher than compared to the inconsistent thermo-physical property. Also temperature drop close to the tip of the fin is higher at higher Gr, indicating higher heat transfer rate. Finally, for overall Nusselt number a correlation with the governing parametyers for the present investigation is developed.