UNSTEADY NUMERICAL SIMULATION OF TURBULENT FORCED CONVECTION IN A RECTANGULAR PIPE PROVIDED WITH WAVED POROUS BAFFLES

Authors : Fakiri Fethallah

Pages : 1466-1477

Doi:10.18186/journal-of-thermal-engineering.338907

View : 18 | Download : 6

Publication Date : 2017-10-01

Article Type : Research

Abstract :Numerical simulations of flow and heat transfer in a serpentine heat exchanger configuration are presented to demonstrate application of porous media techniques in heat exchanger analyses. In this study, steady-state 3D turbulent forced convection flow and heat transfer characteristics in a rectangular pipe with baffles attached inside pipe have been numerically investigated under constant wall heat flux boundary condition. Numerical study has been carried out for Reynolds number of 20000-50,000, Prandtl number of 0.71, baffle distances h/D h of 1/3 and 2/3, and baffle thickness e of 1/12, 2/3. It is observed that rectangular pipe having waved baffles has a higher Nusselt number and friction factor compared to the smooth rectangular pipe without baffles. Periodically fully developed conditions are obtained after a certain module. Maximum thermal performance factor is obtained for the baffle waved. Results show that baffle distance, waved porous baffle, and Reynolds number play important role on both flow and heat transfer characteristics. All the numerical results are correlated within accuracy of ±2% and ±2.5% for average Nusselt number and friction factor, respectively.
Keywords : Porous media, Horizontal Canal, Thermal transfer and matter, Model Darcy-Brinkman-Forchheimer, Forced convection, Porous baffles