Akademik Veri Yönetim Sistemi
Isi Bilimi Ve Teknigi Dergisi/ Journal of Thermal Science and Technology, cilt.46, sa.1, ss.141-155, 2026 (SCI-Expanded, Scopus)
This study investigates the interplay between geometric spacing, thermal boundary conditions, and three-dimensional flow structures on heat transfer and aerodynamic performance in tandem finite circular cylinders. Two finite circular cylinders of diameter D and aspect ratio AR=3 placed vertically on the bottom wall (ground plane) of the computational domain are subjected to uniform external flow resulting in a Re=20000. The distance between the cylinders S was varied as S=D, 2D, 4D. The turbulence model SST k-ω is employed to solve the governing equations. First, a numerical verification study was conducted to determine the most suitable turbulence model and grid configuration using a single 3D cylinder for which benchmark data are available in the literature. Subsequently, the flow field is simulated for two cylinders arranged in a tandem configuration. As a significant new contribution to the literature, the primary turbulence and flow characteristics across the computational domain and on each cylinder surface are systematically identified and presented in tabular form. The heat transfer performance over isothermal cylinders is evaluated using the mean and local Nusselt number distributions, providing insights for design optimization. While no Kármán vortex street forms at S/D=1 due to irregular vortex shedding, a stable Kármán vortex street is observed at S/D=4. In terms of heat transfer, the highest performance is observed at S/D=1 for the upstream cylinder and at S/D=4 for the downstream cylinder. For the upstream cylinder, the average Nusselt number decreases by 13.9% from S/D=1 to S/D=2 and increases by 3.6% from S/D=2 to S/D=4. For the downstream cylinder, the average Nusselt number decreases by 12.6% from S/D=1 to S/D=2 and increases by 19.1% from S/D=2 to S/D=4.