Effect of Acceleration on Bottom Shear Stress in Tidal Estuaries
Publication: Journal of Waterway, Port, Coastal, and Ocean Engineering
Volume 122, Issue 2
Abstract
A formulation specifying the bottom shear stress boundary condition for an unsteady, tidal flow model is derived through theoretical analysis. The unsteady boundary layer equation is solved for the velocity distribution adjacent to the boundary using a regular perturbation expansion. When applied to the bottom layer of the computation grid of a numerical model, the solution relates the bottom shear stress to the velocity and acceleration computed in that layer. Numerical experiments with a hypothetical homogeneous estuary indicate that the error in calculated bottom stress increases with vertical grid spacing if the logarithmic profile is used to relate bottom stress to velocity. The use of the formulation including the correction terms can significantly reduce this error and adequately specify the boundary condition in a numerical model of estuarine flow with a practical range of vertical grid spacing. The numerical experiments also show that, if the roughness height and bottom stress are estimated by fitting a logarithmic profile to the velocity distribution, they may be off by more than 100%.
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References
1.
Anwar, H. O.(1981). “A study of the turbulent structure in a tidal flow.”Estuarine, Coast. and Shelf Sci., 13, 373–387.
2.
Anwar, H. O.(1983). “Turbulence measurements in stratified and well-mixed estuarine flows.”Estuarine, Coast. and Shelf Sci., 17, 243–260.
3.
Anwar, H. O., and Atkins, R.(1980). “Turbulence measurements in simulated tidal flow.”J. Hydr. Div., ASCE, 106(8), 1273–1289.
4.
Anwar, H. O., and Atkins, R. (1982). “Closure to `Turbulence measurements in simulated tidal flow.”' J. Hydr. Div., ASCE, 108(2), 286–289.
5.
Arya, S. P. S.(1973). “Neutral planetary boundary layer above a nonhomogeneous surface.”Geophys. Fluid Dynamics, 4, 333–355.
6.
Galperin, B., Kantha, L. H., Hassid, S., and Rosati, A.(1988). “A quasi-equilibrium turbulent energy model for geophysical flows.”J. Atmospheric Sci., 45, 55–62.
7.
Gordon, C. M.(1975). “Sediment entrainment and suspension in a turbulent flow.”Marine Geol., 18, 57–64.
8.
Gross, T. F., and Nowell, A. R. M.(1983). “Mean flow and turbulence scaling in a tidal boundary layer.”Continental Shelf Res., 2, 109–126.
9.
Hamrick, J. M. (1992). “A three-dimensional environmental fluid dynamics computer code: Theoretical and computational aspects.”Gloucester Pt. Va. Spec. Rep. in Appl. Marine Sci. and Oc. Engrg., Virginia Institute of Marine Science, 139.
10.
Lavelle, J. W., and Mofjeld, H. O. (1983). “Effects of time-varying viscosity on oscillatory turbulent channel flow.”J. Geophys. Res., 88(C12), 7607–7616.
11.
Lundgren, H. (1972). “Turbulent currents in the presence of wave.”Proc., 13th Coast. Engrg., Conf., ASCE, New York, N.Y., 623–634.
12.
Mellor, G. L., and Yamada, T.(1982). “Development of a turbulence closure model for geophysical fluid problems.”Rev. Geophys. Space Phys., 20, 851–875.
13.
Soulsby, R. L., and Dyer, K. R. (1981). “The form of the near-bed velocity profile in a tidally accelerating flow.”J. Geophys. Res., 86(C9), 8067–8074.
14.
Wilkinson, R. H.(1986). “Variation of roughness length of a mobile sand bed in a tidal flow.”Geo-Marine Letters, 5, 231–239.
15.
Wright, L. D.(1989). “Benthic boundary layers of estuarine and coastal environments.”Rev. in Aquatic Sci., 1, 75–95.
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Copyright © 1996 American Society of Civil Engineers.
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Published online: Mar 1, 1996
Published in print: Mar 1996
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