Thermally developing flow of Al2O3-water nanofluid through regular N-sided polygonal ducts: A semi-analytic weighted residuals approach

چکیده مقاله

A semi-analytical approach is proposed to solve the hydrodynamically fully developed and thermally developing flow and heat transfer of Al2O3-water nanofluid through N-sided polygonal ducts.Using the Galerkin weighted residuals method,closed-form solutions for the flow and temperature fields in various polygonal ducts for the constant wall temperature nduniformwallheatfluxboundaryconditionsareobtained.VariationsoftheNusseltnumber along the axial direction for different duct geometries and different volume fraction of the nanoparticles are presented. Comparisons of the results for special cases with the existing results from the literature indicate that the employed method is quite accurate.The results show that the heat transfer enhances with increasing the nanoparticles volume fraction.