Natural Convection of CuO-Water Nanofluid Flow along a Vertical Plate with Variable Thermophysical Properties and Discrete Heat Sources

Effects of discrete heat sources along a vertical plate are of practical importance due their occurrence in electronic devices. For growing demand of electronic appliances and their advancement, cooling processes of them must be improved. As usual fluids have limited heat transfer, nanofluids made by dispersing nanoparticles into them are utilized to enhance thermal performance. However, flow characteristics and heat transfer of a nanofluid for discrete heat sources along a vertical plate need to be explored. For this reason, this study analyzes the natural convective heat transfer and flow behaviors of CuO-water nanofluid induced by discrete heat sources along a vertical plate. The influences of variable thermophysical properties of the nanofluid, thermal radiation, and magnetic field are also considered. Using the finite difference method, the nonsimilar governing equations have been solved. Results reveal that for increasing surface temperature and radiation parameters, the shear stress (ST) and rate of heat transfer (HT), and their average values are increased. However, the opposite is observed for the magnetic parameter. For increasing ambient temperature and nanoparticles' volume fraction, the ST increases and the rate of HT decreases. An increase in the magnetic parameter, nanoparticles' volume fraction, and ambient temperature leads to a decrease in the magnitude of stream function; however, it causes an increase in the momentum and thermal boundary layers. Interestingly, a comparison reveals that the model for constant properties of the nanofluid provides a decrease in heat transfer by an average of about 7.8% compared to that for variable properties.