Experimental study of natural convection heat transfer enhancement in a square cavity filled with nanofluid using magnetic effects

Abstract

Researchers in heat transfer are paying close attention to nanofluids because of their potential as highperformance thermal transport media. In light of natural convection's enormous significance, the addition of nanoparticles significantly enhances the thermophysical properties of the nanofluids compared to the base fluid. In this study, experimental work was used to evaluate the influence of CuO nanoparticles on natural convection with magnetohydrodynamic (MHD) flow in a square cavity. The cavity's left and right vertical walls were maintained at different temperatures, and the top and bottom walls of the cavity were insulated. This experimental study applied a horizontal magnetic field with uniform strength. Results were obtained for a variety of Hartmann numbers ranging from 0-300, Rayleigh numbers going from 2.76E+8 to 6.89E+8, and solid volume fractions ranging from 0 to 1.5%Vol. Results showed that the heat transfer coefficient and Nusselt number values decreased with the increase in the values of the Hartmann number, except for the heat transfer coefficients at Ha=100 and 150 are larger than the heat transfer coefficients at Ha= 0. The maximum heat transfer coefficient and Nusselt number enhancement were 40.8% and 28.5%, respectively, at a 1.5% volume concentration of CuO-water nanofluid, Ra= 6.7E+8 and Ha=100 compared with pure fluid (water) at Ha=0.