Mixed convection due to a rotating cylinder in a 3D corrugated cavity filled with single walled CNT-water nanofluid

Abstract

Analysis of mixed convection due to a rotating inner cylinder in a corrugated three-dimensional cavity filled with carbon nanotube-water nanofluid was performed. Numerical simulations were performed by using Galerkin weighted residual finite element method. The three-dimensional corrugated cavity was differentially heated form the vertical surfaces, and an inner rotating adiabatic cylinder was used. Influence of Rayleigh number (between 10 $$^4$$ and 10 $$^6$$ ), angular rotational velocity of the cylinder (between − 50 and 50 rad/s), height (between H / 10 and H / 3) and number of triangular waves (between 1 and 16) and solid nanoparticle volume fraction (between 0 and 0.04) on the convective heat transfer characteristics was analyzed. It was observed that average heat transfer augments significantly by changing the nanoparticle volume fraction and up to 128 $$\%$$ of enhancement is obtained. Depending on the rotational direction of the cylinder, average Nusselt number enhances $$68\%$$ in the three-dimensional cavity. Surface corrugation parameters are not as effective as solid particle volume fraction and angular rotational speed of the cylinder on the heat transfer enhancements. Finally, a correlation for the average Nusselt number along the cold surface was provided which is dependent upon the angular rotational speed of the cylinder and Rayleigh number.