Effects of horizontally two-dimensional bodies on the mass transport near the sea bottom

1977 ◽  
Vol 83 (3) ◽  
pp. 415-431 ◽  
Author(s):  
Jacques Lamoure ◽  
Chiang C. Mei
Keyword(s):  
Boundary Layer ◽  
Mass Transport ◽  
Experimental Evidence ◽  
Coriolis Force ◽  
Gravity Waves ◽  
Harmonic Waves ◽  
Two Dimensional ◽  
Convex Corner ◽  
Horizontal Dimension ◽  
Sea Bottom

Mass transport close to the sea bottom is investigated for simple harmonic waves around a body with a small horizontal dimension. For gravity waves it is shown that the mass transport very near the bottom points towards a convex corner, but near the top of the boundary layer its direction reverses. Possible implications for silting near a pile and a harbour entrance are discussed and some experimental evidence given. For tides, the Coriolis force introduces a spiralling variation within the boundary layer, and possible inferences for coastline modification are drawn.

Double boundary layers in standing interfacial waves

1976 ◽  
Vol 76 (4) ◽  
pp. 819-828 ◽  
Author(s):  
B. D. Dore
Keyword(s):  
Boundary Layer ◽  
Mass Transport ◽  
Layer Structure ◽  
Standing Waves ◽  
Boundary Layer Theory ◽  
Two Dimensional ◽  
Transport Velocity ◽  
Oscillatory Velocity ◽  
Mass Transport Velocity ◽  
The Mean

The double-boundary-layer theory of Stuart (1963, 1966) and Riley (1965, 1967) is employed to investigate the mass transport velocity due to two-dimensional standing waves in a system comprising two homogeneous fluids of different densities and viscosities. The most important double-boundary-layer structure occurs in the neighbourhood of the oscillating interface, and the possible existence of jet-like motions is envisaged at nodal positions, owing to the nature of the mean flows in the layers. In practice, the magnitude of the mass transport velocity can be a significant fraction of that of the primary, oscillatory velocity.

Stabilizing and Destabilizing Effects of Coriolis Force on Two-Dimensional Laminar and Turbulent Boundary Layers

1979 ◽  
Vol 101 (1) ◽  
pp. 23-29 ◽  
Author(s):  
H. Koyama ◽  
S. Masuda ◽  
I. Ariga ◽  
I. Watanabe
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Coriolis Force ◽  
Stable Boundary Layer ◽  
Numerical Evaluation ◽  
Critical Reynolds Number ◽  
Turbulent Boundary Layers ◽  
Two Dimensional ◽  
Boundary Layer Development ◽  
Layer Development

To investigate the effects of Coriolis force on two-dimensional laminar and turbulent boundary layers, quantitative experiments were performed. A numerical evaluation was also carried out utilizing the Monin-Oboukhov coefficient including the effect of rotation. From the experimental results, the boundary layer development was found to be promoted on the unstable side and suppressed on the stable side, in comparison with the case of zero-rotation. In the stable boundary layer, the critical Reynolds number for relaminarization was observed to increase as rotation number was decreased. Calculated results were seen to predict the stabilizing effect of Coriolis force fairly well.

Characteristics of the secondary circulations in the convective boundary layer over two-dimensional heterogeneous surfaces

2020 ◽  
Author(s):  
Zixuan Xiang ◽  
Jianning Sun ◽  
Jun Zou
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Coriolis Force ◽  
Convective Boundary Layer ◽  
Sensible Heat Flux ◽  
Two Dimensional ◽  
Background Wind ◽  
Convective Boundary ◽  
Boundary Layer Height ◽  
Secondary Circulations

<p>Large-eddy simulations are performed to investigate the effects of background wind on the secondary circulations (SCs) in the convective boundary layer. Heterogeneities are produced by a prescribed two-dimensional surface sensible heat flux pattern of chessboard-type and have a size which is a bit larger than the boundary layer height.</p><p>When the wind blows along the diagonal of the chessboard-like pattern, the roll-like SCs are observed even when the background wind speed is as large as 10m/s, with whose axes are oriented along the diagonal of the pattern. Another case with wind direction along neither the diagonal nor the side of the chessboard-like pattern and weak wind speed shows the roll-like SCs still exist but lack symmetry. The SCs become much weaker and change their axes orientation when the wind speed increases.</p><p>Meanwhile, the results are different when the Coriolis force is considered. When the background wind is weak, the asymmetry of the SCs become more significant with the development of boundary layer when the Coriolis force is considered, while the SCs tend to be symmetrical without the Coriolis force. When the background wind strengthens, the SCs are more difficult to maintain in the case of Coriolis force.</p><p>Further analysis through rotational and divergent decomposition suggests which part contributes more to the maintenance of the SCs.</p><p></p>

scholarly journals Stabilizing Effects of Coriolis Force upon Two-Dimensional Turbulent Boundary Layer

1977 ◽  
Vol 43 (374) ◽  
pp. 3797-3807
Author(s):  
Hideharu KOYAMA ◽  
Shuichi KIMURA ◽  
Shigeaki MASUDA ◽  
Ichiro ARIGA ◽  
Ichiro WATANABE
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Coriolis Force ◽  
Two Dimensional

The Departure from Equilibrium of Turbulent Boundary Layers

1968 ◽  
Vol 19 (1) ◽  
pp. 1-19 ◽  
Author(s):  
H. McDonald
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Kinetic Energy ◽  
Stress Distribution ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Two Dimensional ◽  
Pressure Distributions ◽  
Momentum Integral ◽  
State Examination

SummaryRecently two authors, Nash and Goldberg, have suggested, intuitively, that the rate at which the shear stress distribution in an incompressible, two-dimensional, turbulent boundary layer would return to its equilibrium value is directly proportional to the extent of the departure from the equilibrium state. Examination of the behaviour of the integral properties of the boundary layer supports this hypothesis. In the present paper a relationship similar to the suggestion of Nash and Goldberg is derived from the local balance of the kinetic energy of the turbulence. Coupling this simple derived relationship to the boundary layer momentum and moment-of-momentum integral equations results in quite accurate predictions of the behaviour of non-equilibrium turbulent boundary layers in arbitrary adverse (given) pressure distributions.

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