Numerical Simulation of Flow, Natural Convection and Distribution of Nano Particles Inside Trapezoidal Cavity using Buongiorno’s Two-Phase Model

In the present study, natural convection of Al2O3–water nanofluid and nano-particles local distribution inside trapezium enclosure has been investigated using non-homogenous two-phase Buongiorno’s model. The effect of the variation of trapezium enclosure inclantion angle on heat transfere, mass and momentum has been investigated. The governing equations of the problem are momentum, energy and volume fraction of nanoparticles that are solved using the finite volume method and the SIMPLE algorithm. Diffusion and convective terms are descritized using a second-order central difference and upwind schemes. The left and right walls of cavity are kept at constant temperatures Th and Tc, respectively, while the other walls are thermally insulated. Using the finite volume method and the SIMPLE algorithm, the governing equations have been discretized. Simulations have been carried out for different inclination angle( ), Rayleigh number(102≤Ra≤104) as well as particle average volume fraction (φ) ranging from 0.01 to 0.04. Results show that at low Rayleigh number for a specific particle volume fraction, with increasing the inclination angle from zero to 45 degree, the average Nusselt number (NuAve)and heat transfer decreases 81%. On the other hand, optimum results were obtained for the inclination angle of 30 degree. The Nuselt enhancement percent was obtained 5.5 compared to the square enclosure and 6.8 compared to inclination angle of 45 degrees. Results also showed a uniform distribution for nanoparticles in high Rayleigh numbers and in enclosures with different inclination angle.