Two-phase study of nanofluids mixed convection and entropy generation in an I-shaped porous cavity with triangular hot block and different aspect ratios

The nanofluids mixed convection in a porous I-shaped cavity using Buongiorno's method of nanofluids simulation is reported in this paper. The nanofluids have been assumed as a mixture of water and TiO2 nanoparticles up to 4% of volume concentration. Having accurate prediction of thermal properties of nanofluids is crucial for a numerical solution. Thus, a new predictive correlation for effective thermal conductivity is developed using the multivariable regression method with a high accuracy compared to the experimental data. Six different problems, including two different porous media and three different aspect ratios of the cavity, are solved implementing the finite volume method. As the first time, an internal triangular hot block in a cavity has been studied. The results showed that the entropy generation reduces with any increase in the aspect ratio of the cavity and the nanoparticle volume concentration. Any increase in the nanoparticle volume concentration also leads to enhance the average Nusselt number, in all considered aspect ratios.