Mean flow generation in a rotating homogeneous flow

1996 ◽  
Author(s):  
Xuizhang Zhang ◽  
Don Boyer
Keyword(s):  
Mean Flow ◽  
Homogeneous Flow ◽  
Flow Generation

Mean flow generation along a sloping region in a rotating homogeneous fluid

1996 ◽  
Vol 101 (C12) ◽  
pp. 28597-28614 ◽  
Author(s):  
Xiuzhang Zhang ◽  
Don L. Boyer ◽  
Nicolas Pérenne ◽  
Dominique P. Renouard
Keyword(s):  
Mean Flow ◽  
Homogeneous Fluid ◽  
Flow Generation

scholarly journals Streaming by leaky surface acoustic waves

2010 ◽  
Vol 467 (2130) ◽  
pp. 1779-1800 ◽  
Author(s):  
J. Vanneste ◽  
O. Bühler
Keyword(s):  
Surface Waves ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Stokes Drift ◽  
Mean Flow ◽  
Matched Asymptotics ◽  
Flow Generation ◽  
Solid Liquid Interface ◽  
Solid Liquid

Acoustic streaming, the generation of mean flow by dissipating acoustic waves, provides a promising method for flow pumping in microfluidic devices. In recent years, several groups have been experimenting with acoustic streaming induced by leaky surface waves: (Rayleigh) surface waves excited in a piezoelectric solid interact with a small volume of fluid where they generate acoustic waves and, as result of the viscous dissipation of these waves, a mean flow. We discuss the computation of the corresponding Lagrangian mean flow, which controls the trajectories of fluid particles and hence the mixing properties of the flows generated by this method. The problem is formulated using the averaged vorticity equation which extracts the dominant balance between wave dissipation and mean-flow dissipation. Particular attention is paid to the thin boundary layer that forms at the solid/liquid interface, where the flow is best computed using matched asymptotics. This leads to an explicit expression for a slip velocity, which includes the effect of the oscillations of the boundary. The Lagrangian mean flow is naturally separated into three contributions: an interior-driven Eulerian mean flow, a boundary-driven Eulerian mean flow and the Stokes drift. A scale analysis indicates that the latter two contributions can be neglected in devices much larger than the acoustic wavelength but need to be taken into account in smaller devices. A simple two-dimensional model of mean flow generation by surface acoustic waves is discussed as an illustration.

Mean flow generation due to longitudinal librations of sidewalls of a rotating annulus

2020 ◽  
Vol 114 (6) ◽  
pp. 742-762
Author(s):  
Michael V. Kurgansky ◽  
Torsten Seelig ◽  
Marten Klein ◽  
Andreas Will ◽  
Uwe Harlander
Keyword(s):  
Mean Flow ◽  
Flow Generation

Mean flow generation in a two-layer system under circularly polarized vibrations

2011 ◽  
Vol 46 (4) ◽  
pp. 536-547
Author(s):  
D. V. Lyubimov ◽  
G. L. Khil’ko
Keyword(s):  
Mean Flow ◽  
Layer System ◽  
Circularly Polarized ◽  
Flow Generation

scholarly journals Rossby Waves and Jets in Two-Dimensional Decaying Turbulence on a Rotating Sphere

2007 ◽  
Vol 64 (12) ◽  
pp. 4246-4269 ◽  
Author(s):  
Yoshi-Yuki Hayashi ◽  
Seiya Nishizawa ◽  
Shin-ichi Takehiro ◽  
Michio Yamada ◽  
Keiichi Ishioka ◽  
...  
Keyword(s):  
Rossby Waves ◽  
Momentum Transport ◽  
Two Dimensional ◽  
Mean Flow ◽  
Jet Formation ◽  
Rotating Sphere ◽  
Angular Momentum Transport ◽  
Flow Generation ◽  
Flow Directions ◽  
Decaying Turbulence

Abstract Jet formation in decaying two-dimensional turbulence on a rotating sphere is reviewed from the viewpoint of Rossby waves. A series of calculations are performed to confirm the behavior of zonal mean flow generation on the parameter space of the rotation rate Ω and Froude number Fr. When the flow is nondivergent and Ω is large, intense easterly circumpolar jets tend to emerge in addition to the appearance of a banded structure of zonal mean flows with alternating flow directions. When the system allows surface elevation, circumpolar jets disappear and an equatorial easterly jet emerges with increasing Fr. The appearance of the intense easterly jets can be understood by the angular-momentum transport associated with the generation, propagation, and absorption of Rossby waves. When the flow is nondivergent, long Rossby waves tend to be absorbed near the poles. In contrast, when Fr is large, Rossby waves can hardly propagate poleward and tend to be absorbed near the equator.

scholarly journals Stream Flow Generation for Simulating Yearly Bed Change at an Ungauged Stream in Monsoon Region

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 554
Author(s):  
Woong Hee Lee ◽  
Heung Sik Choi ◽  
Dongwoo Lee ◽  
Byungwoong Choi
Keyword(s):  
Stream Flow ◽  
Mean Bias Error ◽  
Percentage Error ◽  
Bias Error ◽  
Monsoon Region ◽  
Mean Flow ◽  
Bankfull Discharge ◽  
River Bed ◽  
Flow Generation ◽  
Annual Discharge

The stream flow generation method is necessary for predicting yearly bed change at an ungauged stream in Monsoon region where there is no hydrologic and hydraulic information. This study developed the stream flow generation method of daily mean flow for each month over a year for bed change simulation at an ungauged stream. The hydraulic geometries of cross-sections and the corresponding bankfull indicators of the Byeongseong river of 4 km reach were analyzed to estimate the bankfull discharge. The estimated bankfull discharge of the target reach was 77.50 m3/s, and the total annual discharge estimated 3720 m3/s through the correlation equation with the bankfull discharge. The measured total annual discharge of the Byeongseong river was 3887.30 m3/s, which is greater by 167.30 m3/s of 4.3% relative error. The volume and bed changes over a year by the Center for Computational Hydroscience and Engineering Two-Dimension (CCHE2D) model simulated using the measured discharge during 2013 and 2014 coincided with the surveyed in the same period. Estimated total annual discharge was used for the scenarios of stream flow generation. The generated stream flow using the flow apportioned to each month on the basis of the flow percentage in an adjacent stream simulated the river bed most appropriately. The generated stream flow using the flow based on the monthly rainfall percentage of the rainfall station in the target stream basin also simulated river bed well, which is confirmed as an alternative. Quantitatively, the root mean square error (RMSE), mean bias error (MBE), and mean absolute percentage error (MAPE) in-depth change of thalweg between the measured and the simulated were found to be 0.25 m, 0.04 m, and 0.44%, respectively. The result of the simulated cross-sectional river bed change for target reach coincided well with the surveyed. The proposed method is highly applicable to generate the stream flow for analyzing the yearly bed change at an ungauged stream in Monsoon region.

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