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-Boussineśq and Boussineśq 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-Boussineśq fluid in natural convection for variable properties. Computation demonstrates a maximum of 9% higher overall Nu for fixed property Boussineśq fluid than compared to the non-Boussineśq fluid. And for the Boussineśq 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.

Keywords

• Natural convection; Non-Boussineśq; Variable property; Nusselt number.