TY - GEN
T1 - Direct numerical simulations of variable-aspect-ratio turbulent duct flows at low to moderate reynolds numbers
AU - Vinuesa, Ricardo
AU - Noorani, Azad
AU - Lozano-Durán, Adrián
AU - El Khoury, George
AU - Schlatter, Philipp
AU - Fischer, Paul F.
AU - Nagib, Hassan M.
PY - 2013
Y1 - 2013
N2 - Three-dimensional effects in turbulent duct flows, i.e., side-wall boundary layers and secondary motions, are studied by means of direct numerical simulations (DNS). The spectral element code Nek5000 is used to compute turbulent duct flows with aspect ratios 1 to 7 (at Reb, c = 2800, Reτ 180) and 1 (at Reb, c = 5600, Reτ 330) in streamwiseperiodic boxes of length 25h. The total number of grid points ranges from 28 to 145 million, and the fluid kinematic viscosity n was adjusted iteratively in order to keep the same bulk Reynolds number at the centerplane with changing aspect ratio. Spanwise variations in wall shear, mean-flow profiles and turbulence statistics are analyzed with aspect ratio, and also compared with the 2D channel. These computations show good agreement with experimental measurements carried out at IIT in parallel, and reinforces one important conclusion: the conditions obtained in the core region of a high-aspect-ratio duct cannot exactly be reproduced by spanwise-periodic DNSs of turbulent channel flows.
AB - Three-dimensional effects in turbulent duct flows, i.e., side-wall boundary layers and secondary motions, are studied by means of direct numerical simulations (DNS). The spectral element code Nek5000 is used to compute turbulent duct flows with aspect ratios 1 to 7 (at Reb, c = 2800, Reτ 180) and 1 (at Reb, c = 5600, Reτ 330) in streamwiseperiodic boxes of length 25h. The total number of grid points ranges from 28 to 145 million, and the fluid kinematic viscosity n was adjusted iteratively in order to keep the same bulk Reynolds number at the centerplane with changing aspect ratio. Spanwise variations in wall shear, mean-flow profiles and turbulence statistics are analyzed with aspect ratio, and also compared with the 2D channel. These computations show good agreement with experimental measurements carried out at IIT in parallel, and reinforces one important conclusion: the conditions obtained in the core region of a high-aspect-ratio duct cannot exactly be reproduced by spanwise-periodic DNSs of turbulent channel flows.
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M3 - Conference contribution
AN - SCOPUS:85034016810
T3 - International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2013
BT - International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2013
PB - TSFP-8
T2 - 8th International Symposium on Turbulence and Shear Flow Phenomena, TSFP 2013
Y2 - 28 August 2013 through 30 August 2013
ER -