Numerical study of natural convection nanofluids flow in tilted cavities with a partially thermally heat source

Abstract

Numerically, natural convection heat transfer of nanofluids in a two-dimensional tilt square enclosure was investigated, with a partial heat source embedded on the bottom wall subject to a fixed heat flux. The remaining portions of the horizontal bottom wall are assumed to be adiabatic, while the upper horizontal wall and the vertical ones are supposed to be at a relatively low temperature. Using the finite volume method and the SIMPLER algorithm, the governing equations have been discretized and solved. Simulations have been carried out for more than one nanoparticle and base fluid, a range of Rayleigh numbers ( 10 3 ≤ Ra ≤ 10 6 ), various values of heat source length and location (0.2 ≤ B ≤ 0.8 and 0.2 ≤ D ≤ 0.5, respectively), solid volume fraction ( 0 ≤ ϕ ≤ 20 % ) as well as tilt angle ( 0 ° ≤ φ ≤ 90 ° ). The results indicate that the heat transfer performance increases by adding nanoparticles into the base fluid. An optimum solid volume fraction raises and reduces the heat transfer rate and maximum temperature of the surface heat source. respectively. Moreover, the results show a significant impact of the tilt angle on the flow, temperature patterns, and the heat transfer rate with a specific tilt angle depending to the pertinent parameters.