Chakrit SuvanjumratMahidol University2018-12-212019-03-142018-12-212019-03-142017-09-29Engineering Journal. Vol.21, No.5 (2017), 225-241012582812-s2.0-85032015863https://repository.li.mahidol.ac.th/handle/20.500.14594/42557© 2017, Chulalongkorn University 1. All rights reserved. The open source code software (OpenFOAM) was applied to simulate the thermal convection of airflow. The fresh inlet airflow past a circular cylindrical heater through the variable cross-section duct by the centrifugal fan had been employed to study the thermal convection phenomenon. The widely used k-εturbulence model was implemented to simulate the thermal convection of airflow. The pressure-velocity coupling was used an effective steady state algorithm, SIMPLE algorithm, for solving a zero pressure gradient problem. The upwind differencing (UD), linear upwind differencing (LUD), QUICK, and TVD scheme were the important schemes which were selected to solve convection-diffusion problems of the airflow past a circular cylindrical heater. The thermal convection experiment was setup using the P3210 heat transfer bench of Cussons technology. The velocities of airflow had been adjusted from 5 to 20 m/s by opening a cap at the exhaust fan duct. The heater temperatures were controlled at 100, 150 and 200 °C. The computational fluid dynamics (CFD) results were compared with the experimental data. The comparison between CFD models and physical experiments were in good agreement. The average error of the k-ε turbulence model by solving with the SIMPLE algorithm, UD scheme for velocity, and QUICK scheme for temperature results was less than 4.25 % when compared with the experimental data.Mahidol UniversityEngineeringArticleSCOPUS10.4186/ej.2017.21.5.225