Improved incompressible SPH method for natural-convection from heated T-open pipe of Al2O3-water nanofluid in a cavity: Buongiorno’s two-phase model

Abstract

The unsteady natural-convection of Al2O3-water nanofluid form heated open T-pipe inside a cavity has been investigated by incompressible smoothed particle hydrodynamic (ISPH) method using non-homogenous two-phase Buongiorno?s model. Different lengths and heights of T-pipe shape are considered. The side walls of the cavity are kept at cool temperature Tc and the horizontal walls are thermally insulated. The Lagrangian description of the controlling governing equations is discretized and solved using improved ISPH method. In this study, ISPH method is improved using kernel renormalization function for boundary treatment plus modification in the source term of pressure Poisson equation. The source term of pressure Poisson equation contains the velocity divergence plus density invariance multiply by relaxation coefficient. The calculations are performed for variable lengths of T-open pipe (0.2 ? Lb ? 0.6), variable widths of T-open pipe (0.02 ? Wb ? 0.16), (0.02 ? Wt ? 0.16), and variable concentration of nanoparticles volume fraction (1% ? ?avg ? 10%). The obtained results showed that the maximum values of the stream function are reduced by 80.8% when ?avg is increased from 1-10%. Additionally, as lengths and widths of the T-pipe are raised, the average Nusselt numbers at the vertical walls are enhanced.