Akademik Veri Yönetim Sistemi
Chemical and Process Engineering - Inzynieria Chemiczna i Procesowa, cilt.29, sa.4, ss.1053-1070, 2008 (SCI-Expanded)
A numerical study has been carried out of heat transfer enhancement and flow characteristics through artificial porous materials in the form of ring turbulators on heated wall of a circular pipe for turbulent flow (Reynolds number range 16 000-64 000). In the study, uniform heat flux of 2500 W/m2 from a circular pipe wall surface has been assumed. A significant enhancement of heat transfer in the porous-ring turbulators is observed compared with that in a smooth surface. Four various shapes of porous-ring turbulators (0 (solid), 0.2, 0.4 and 1 (smooth circular pipe) porosity) have been examined using the RNG k-e turbulence model, and compared based on heat transfer enhancement and friction characteristics. Heat transfer decreases with increasing porosity. Using porous-ring turbulators in the pipe gives an increase in the Nusselt number and heat transfer enhancement. Therefore, such turbulators may be used in heat exchangers to increase heat transfer and energy saving.