Özet:

In this study, heat transfer from circular hollow and trapezoidal model copper plate surfaces with a constant heat flux of 1000 W/m2 and flow structures in combined jet flow channels were numerically investigated using water, 2% volumetric concentration CuO-Water (Copper oxide)-Water and Diamond-Water nanofluids. The numerical study was carried out steady and in three dimensions by using the Ansys-Fluent program with the k-ε turbulence model. In addition, 45o and 90o angled fins have been added to the channels at a fixed distance (N) in the size of the D jet inlet diameter from the jet inlet. While the channel height is 3D, the Re number range of the fluids is 5000-15000. The accuracy and acceptability of the results obtained from the study were proven by using the equation obtained as a result of experimental research. The results of the study were evaluated comparatively in the finless and finned conditions for water and nanofluids as variations in the average Nu number for each model in the channels. Also, the velocity and temperature contour distributions of the combined jet flow for the CuO-Water nanofluid were presented for different fin angles. However, performance evaluation numbers (PEC) at different Reynolds numbers and mean Nu number (Num) and surface temperature values (Tm) were analyzed for Re=5000 and 15000 for all three model surfaces in the channels. For Re=15000, 27.57% and 26.11% increases in the Num number were obtained compared to the channels without fin and water-fluid for the use of Diamond-Water and Copper oxide-Water nanofluids, respectively, on the trapezoidal model surface in the 90o finned channel. In addition, the PEC number values for water fluid in channels with 90o angled fins at Re=15000 value were found to be 1.1%-1.31% and 0.82%-%0.63 higher compared to Diamond-Water and CuO-Water nanofluids on the circular hollow and trapezoidal model surfaces, respectively.

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