Research of cooling performance in combined jet flow channels using different nanofluids

Abstract

In this work, heat transfer from the cube and circular hollow-shaped copper plate surfaces with a constant heat flux of 1000 W/m2 was numerically investigated by using a combination of the cross-flow-impinging jet. Numerical research was performed by solving the energy and Navier-Stokes equations as three-dimensional and steady, using the Ansys-Fluent computer program with the k-ε turbulence model. In order to direct the combined jet flow in the channel to the heated surfaces, the fins with 30o and 60o angles were placed in the channel horizontally with the impinging jet surface. While the channel height ( H) is 4D, the distance of the fin from the jet inlet ( N) is 2D. Fluids used in the channels are water, 0.02% GO-water and 2% diamond-water. The upper and lower surfaces of the channel and the fin are adiabatic and the flow Reynolds number range is 5000–15,000. The results of the work were compared with the experimental results of the studies in the literature and they were found to be consistent with each other. The results were presented as the mean Nu number and mean surface temperature variations for each model surface. Besides, the velocity and temperature contour distributions of the combined jet flow along the channel for diamond-water nanofluid were evaluated. Also, performance evaluation coefficient and average Nu number (Num), and surface temperature values (Tm) were evaluated at different Reynolds numbers for all three patterned surfaces in the channels. At Re = 15,000, there are 18.42% and 17.08% increments in Num value for cube and circular hollow model surfaces in the channel with 60o fin and GO-water nanofluid compared to the channel with water flow and without fin.