NUMERICAL INVESTIGATION OF NANOFLUIDS SWIRAL FLOW IN CIRCULAR TUBE EQUIPPED WITH TWISTED TAPE

چکیده مقاله

This paper reports Computational Fluid Dynamics (CFD) investigations on the friction factor, Nusselt number and thermal performance factor in a tube equipped with twisted tape insert. Numerical investigations are done using Al2O3, CuO, and Fe3O4 – water nanofluids with different volume concentrations in range of Reynolds numbers from 250 to 1000. Furthermore, the effects of twisted tape aspect ratio and Reynolds number on the heat transfer and fluid flow have been studied. The numerical investigations were conducted under uniform heat flux boundary condition. The results showed that the Nusselt number and thermal performance factor of nanofluids flowing in tube equipped with twisted tape were higher than pure water. In addition, the pressure drop of Al2O3-water nanofluid is slightly higher than water and increases by increasing the nanoparticles volume concentration. For better understanding of fluid flow, the flow structure (vector plot and swirl flow pathline) within the tube with twisted tape is also presented. Furthermore, the effects of using different type of water based nanofluids on the fluid flow and heat transfer within circular tube with twisted tape in laminar flow regime with variable thermophysical properties are studied.