NUMERICAL INVESTIGATION ON CONFINED IMPINGING SLOT JETS WITH NANOFLUIDS IN POROUS MEDIA
In this paper a numerical study on mixed convection in confined slot jets impinging on a porous media is carried out. Pure water or Al2O3/water based nanofluids are employed as working fluids; a single-phase model approach has been applied to evaluate their properties. A two-dimensional domain is analyzed and different Peclet and Rayleigh numbers are considered. The local thermal non-equilibrium energy condition is assumed to
accomplish two-dimensional simulations on the system. The examined aluminum foams are characterized by distinct porosity (ε), from 0.90 to about 0.97, for different values of pores per inch (PPI), equal to 5, 10, 20 and 40. The particle volume concentrations range from 0% to 4% and the particle diameter is equal to 30 nm. The target surface is heated by a constant temperature value, calculated according to the value of Rayleigh number. The distance of the target surface is five times greater than the slot jet width. The results show that the convective heat transfer coefficients increase with increasing of values of Peclet number and nanoparticle concentration. Furthermore, the heat transfer coefficient shows a different behavior at varying porosity for
different Peclet and Rayleigh numbers.