TY - JOUR
T1 - Laboratory Test of Second Log-Wake Law for Effects of Ice Cover and Wind Shear Stress on River Velocity Distributions
AU - Shan, Haoyin
AU - Kerenyi, Kornel
AU - Patel, Narendra
AU - Guo, Junke
N1 - Funding Information:
This research was supported by the US Federal Highway Administration Hydraulics R&D Program (Contract DTFH61-349-11-D-00010) through the Genex System to the University of Nebraska-Lincoln. The authors appreciate the constructive comments offered by the three anonymous reviewers, the Associate Editor, and the Editor, which improved this paper significantly during its preparation.
Publisher Copyright:
© 2022 American Society of Civil Engineers.
PY - 2022/6/1
Y1 - 2022/6/1
N2 - The second log-wake law is a small change of the first log-wake law (or Coles' log-wake law) for turbulent pipe and symmetric channel flows but makes a big difference in modeling wall-bounded turbulent flows. It has been extended to antisymmetric Couette channel flows theoretically and open channel flows empirically. A recent study of natural river flows indicates that a river velocity distribution is a superposition of a complete antisymmetric channel flow solution due to water surface shear stress and a half symmetric channel flow solution due to gravity. The objective of this research then is to test this hypothesis under the effects of ice cover and wind-induced water surface shear stress with laboratory experiments. To this end, a special experimental device was designed to simulate the effects of gravity, ice cover, and wind-induced shear stress. With this device, 236 vertical distributions of streamwise velocity were measured with a particle image velocimetry (PIV) technique under various simulated conditions of ice cover and water surface shear stress, 75 of which are plotted in this paper. All measured velocity distributions are characterized by a bowl-shaped velocity distribution with a dip phenomenon, a typical boundary layer velocity distribution, or an S-shaped velocity distribution with an inflection. All of these three distribution patterns are well described by the second log-wake law, which also agrees with real-world river flow data. Based on the second log-wake law, an innovative three-point method is proposed for river discharge measurements.
AB - The second log-wake law is a small change of the first log-wake law (or Coles' log-wake law) for turbulent pipe and symmetric channel flows but makes a big difference in modeling wall-bounded turbulent flows. It has been extended to antisymmetric Couette channel flows theoretically and open channel flows empirically. A recent study of natural river flows indicates that a river velocity distribution is a superposition of a complete antisymmetric channel flow solution due to water surface shear stress and a half symmetric channel flow solution due to gravity. The objective of this research then is to test this hypothesis under the effects of ice cover and wind-induced water surface shear stress with laboratory experiments. To this end, a special experimental device was designed to simulate the effects of gravity, ice cover, and wind-induced shear stress. With this device, 236 vertical distributions of streamwise velocity were measured with a particle image velocimetry (PIV) technique under various simulated conditions of ice cover and water surface shear stress, 75 of which are plotted in this paper. All measured velocity distributions are characterized by a bowl-shaped velocity distribution with a dip phenomenon, a typical boundary layer velocity distribution, or an S-shaped velocity distribution with an inflection. All of these three distribution patterns are well described by the second log-wake law, which also agrees with real-world river flow data. Based on the second log-wake law, an innovative three-point method is proposed for river discharge measurements.
KW - Discharge measurements
KW - Log-wake law
KW - Open channel
KW - River flow
KW - S-shaped velocity profile
KW - Velocity dip phenomena
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U2 - 10.1061/(ASCE)CR.1943-5495.0000277
DO - 10.1061/(ASCE)CR.1943-5495.0000277
M3 - Article
AN - SCOPUS:85126929499
SN - 0887-381X
VL - 36
JO - Journal of Cold Regions Engineering
JF - Journal of Cold Regions Engineering
IS - 2
M1 - 04022001
ER -