TY - JOUR
T1 - Cross flow over two heated cylinders in tandem arrangements at subcritical Reynolds number using large eddy simulations
AU - Afgan, Imran
AU - Kahil, Yacine
AU - Benhamadouche, Sofiane
AU - Ali, Mohamed
AU - Alkaabi, Ahmed
AU - Sofiane Berrouk, Abdallah
AU - Sagaut, Pierre
N1 - Funding Information:
The authors thank the support provided by the UAE Ministry of Education (CRPG-2019, Grant No. 1570604539) and the Emirates Nuclear Technology Center (ENTC), Khalifa University of Science and Technology, UAE. The authors are thankful to Électricité de France (EDF) for providing the computational resources.
Publisher Copyright:
© 2023 The Authors
PY - 2023/4
Y1 - 2023/4
N2 - This study analyses the heat transfer and flow characteristics of cross-flow over two heated infinite cylinders in a tandem (in-line) configuration. Non-isothermal Large Eddy Simulations (LES) using the dynamic Smagorinsky model were conducted at a fixed Reynolds number of 3,000 (based on the free stream velocity and the cylinder diameter). A range of cylinder gap ratios (1.0≤L/D≤5.0) was investigated (in increments of 0.25) with two different Prandtl numbers Pr=0.1 and 1.0. Results show that the flow structures vary according to the order of the patterns: (i) Extended body regime: without attachment for low L/D (1.0-1.25) where cylinders behave as a single bluff body with top–bottom vortex shedding, (ii) Shear layer reattachment regime: with reattachment for moderate L/D (1.5-3.75) where the detached shear layer from the upstream cylinder reattaches to the downstream cylinder, and (iii) Co-shedding regime: for high gap ratios (3.75≤L/D≤5.0) a phenomenon called “jumping”, where the two cylinders behave as isolated bluff bodies. Furthermore, it was observed that the average Nusselt number of both cylinders experience a drastic variation at a critical spacing ratio (between 3.75≤L/D≤4.0). For L/D≤3.0, the average Nusselt number of the upstream cylinder was found to be higher than that of the downstream one. However, for spacing ratios L/D>3.0, the average Nusselt number was similar for both cylinders. For the downstream cylinder, the maximum Nusselt number was located at the separation angle and was found to be independent of the spacing ratio.
AB - This study analyses the heat transfer and flow characteristics of cross-flow over two heated infinite cylinders in a tandem (in-line) configuration. Non-isothermal Large Eddy Simulations (LES) using the dynamic Smagorinsky model were conducted at a fixed Reynolds number of 3,000 (based on the free stream velocity and the cylinder diameter). A range of cylinder gap ratios (1.0≤L/D≤5.0) was investigated (in increments of 0.25) with two different Prandtl numbers Pr=0.1 and 1.0. Results show that the flow structures vary according to the order of the patterns: (i) Extended body regime: without attachment for low L/D (1.0-1.25) where cylinders behave as a single bluff body with top–bottom vortex shedding, (ii) Shear layer reattachment regime: with reattachment for moderate L/D (1.5-3.75) where the detached shear layer from the upstream cylinder reattaches to the downstream cylinder, and (iii) Co-shedding regime: for high gap ratios (3.75≤L/D≤5.0) a phenomenon called “jumping”, where the two cylinders behave as isolated bluff bodies. Furthermore, it was observed that the average Nusselt number of both cylinders experience a drastic variation at a critical spacing ratio (between 3.75≤L/D≤4.0). For L/D≤3.0, the average Nusselt number of the upstream cylinder was found to be higher than that of the downstream one. However, for spacing ratios L/D>3.0, the average Nusselt number was similar for both cylinders. For the downstream cylinder, the maximum Nusselt number was located at the separation angle and was found to be independent of the spacing ratio.
KW - Forced convection
KW - Heat transfer
KW - Large eddy simulation
KW - Nusselt number
KW - Tandem cylinders
KW - Vortex shedding
UR - http://www.scopus.com/inward/record.url?scp=85147928724&partnerID=8YFLogxK
U2 - 10.1016/j.ijheatfluidflow.2023.109115
DO - 10.1016/j.ijheatfluidflow.2023.109115
M3 - Article
AN - SCOPUS:85147928724
SN - 0142-727X
VL - 100
JO - International Journal of Heat and Fluid Flow
JF - International Journal of Heat and Fluid Flow
M1 - 109115
ER -