Turbulent Forced Convection Heat Transfer from Heated Elliptical Tube Bundles to Nanofluids

In recent decades, increasing the heat transfer through the ducts and channels has been one of the biggest concerns in mechanical and electrical systems. In present study, fluid flow and heat transfer in a rectangular channel consisted of elliptical vortex generators with triangular arrangements has been modeled using mixture model. Regarding this, nine elliptical obstacles with different axis ratios in different angles of 0, 30, 45, 60, and 90 degrees have been placed in the channel. Studied fluid in this study iswater/copper-oxide nanofluid with different volume concentration of 0, 2, and 4 percent. Fluid flow in the channel has been considered as a turbulent flow with different Reynolds numbers of 10000, 15000, and 20000 and has been modeled using SST k-ω turbulent scheme. The results show that by increasing Reynold numbers and nanofluid volume concentration, heat transfer is enhanced. In addition, heat transfer in the channel is augmented, when ellipse axis ratios or ellipse position in the channel cause more blockage. This can be attributed to the vortex flow which caused by the abovementioned blocks. In general, the results showed that the maximum heat transfer occurred at the ellipse axis ratio of 1 to 2, 0 degree alignment, 4 percent nanoparticles volume concentration and Reynolds number of 20,000.

کلیدواژه ها:

Mixture model ، Heat transfer ، Turbulent flow ، elliptical vortex generators ، nanofluid