Akademik Veri Yönetim Sistemi
European Journal of Engineering and Natural Sciences, cilt.3, sa.2, ss.65-73, 2019 (Hakemli Dergi)
In this study, effects of inserting twisted tape into a horizontal tube and adding TiO2
nanoparticle to water on heat transfer enhancement performance and pressure drop penalty
are investigated with using CFD program. Analyses are carried out with Reynolds number
of in range from 7860 to 15860, and constant heat flux of 50kW/m2K is applied to wall of
the tube. To simulate turbulent nanofluid flow k-ω standard turbulent model is applied for
all cases. TiO2 particles with diameter of 10 nm dispersed in water with volume fraction
of 0.2% - 2.0% are used as the working fluid. To create swirl flow and enhance heat
transfer, the twisted tape (constant twist ratio is y/W=3.0) is used in this study. The results
show that adding nanoparticle to water causes to get more convective heat transfer
coefficient as from 6% (for 0.2% vol. fract.) to 11% (for 2.0% vol. fract.) in a smooth tube.
Furthermore, both adding nanoparticle to water and inserting the twisted tape to the smooth
tube causes to 1.44 times greater convective heat transfer coefficient than case of smooth
tube and water. In addition to heat transfer performance, pressure drop penalty is
investigated in this study. Increasing nanoparticles in the water increase pressure drop
penalty slightly, but using twisted tape in the smooth tube increases pressure drop penalty
as about 6.5 times more.