TY - JOUR
TI - Effects of Reynolds number, baffle angle, and baffle distance on three-dimensional turbulent flow and heat transfer in a circular pipe
AU - Turgut Oguz
AU - Kizilirmak Erkan
JN - Thermal Science
PY - 2015
VL - 19
IS - 5
SP - 1633
EP - 1648
PT - Article
AB - In this study, steady-state three-dimensional turbulent forced convection  flow and heat transfer characteristics in a circular 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 Re of 3000-50,000, Prandtl number Pr of 0.71, baffle  distances s/D of 1, 2, and 3, and baffle angle a of 30o-150o. Ansys Fluent  12.0.1 software has been used to solve the flow field. It is observed that  circular pipe having baffles has a higher Nusselt number and friction factor  compared to the smooth circular pipe without baffles. Maximum Nusselt number  and friction factor are obtained for the baffle angle of 90o. Nusselt number  increases while baffle distance increases in the range of studied; however,  friction factor decreases. Periodically fully developed conditions are  obtained after a certain module. Thermal performance factor increases with  increasing baffle distance in the rage of studied but decreases with  increasing Reynolds number; maximum thermal performance factor is obtained  for the baffle angle of 150º. Results show that baffle distance, baffle  angle, and Reynolds number play important role on both flow and heat transfer  characteristics. The accuracy of the results obtained in this study is  verified by comparing the results with those available in the literature for  smooth circular pipes. All the numerical results are correlated within  accuracy of ±10 and ±15% for average Nusselt number and Darcy friction  factor, respectively.