Three-dimensional (3D) modeling of non-uniform sediment transport in a channel bend with unsteady flow

2010 ◽  
Vol 48 (6) ◽  
pp. 824-824 ◽  
Author(s):  
Erik Mosselman
Keyword(s):  
Sediment Transport ◽  
Unsteady Flow ◽  
3D Modeling ◽  
Three Dimensional ◽  
Channel Bend

Three-dimensional (3D) modeling of non-uniform sediment transport in a channel bend with unsteady flow

2009 ◽  
Vol 47 (5) ◽  
pp. 670-675 ◽  
Author(s):  
Tim Fischer-Antze ◽  
Nils Rüther ◽  
Nils R.B. Olsen ◽  
Dieter Gutknecht
Keyword(s):  
Sediment Transport ◽  
Unsteady Flow ◽  
3D Modeling ◽  
Three Dimensional ◽  
Channel Bend

Numerical modelling of sediment transport in a channel bend with floating units

2021 ◽  
Author(s):  
Diwash Lal Maskey ◽  
Nils Ruther
Keyword(s):  
Transport Phenomenon ◽  
Sediment Transport ◽  
Numerical Modelling ◽  
Velocity Distribution ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Deposition Pattern ◽  
Bed Deformation ◽  
Channel Bend ◽  
Conceptual Study

<p>Floating units/booms are used to trap or guide floating debris in watercourses. In a relatively shallow depth, these floats could affect the velocity distribution, sediment transport and channel bed deformation.  A three-dimensional non-hydrostatic numerical modelling was performed in a 180 degree channel bend with floats to see the effects in flow distribution and bed deformation as a conceptual study. Different configurations of the floats were simulated. The results showed that the flow velocity increased and deposition decreased at the inner bank of the bend. Use of floating units could be studied to alter sediment deposition pattern and sediment transport phenomenon in watercourses.</p>

"Barbs" for river bend bank protection: application of a three-dimensional numerical model

2007 ◽  
Vol 34 (9) ◽  
pp. 1087-1095 ◽  
Author(s):  
B Minor ◽  
C D Rennie ◽  
R D Townsend
Keyword(s):  
Sediment Transport ◽  
Numerical Model ◽  
Flow Field ◽  
Numerical Models ◽  
Laboratory Data ◽  
Three Dimensional ◽  
Channel Bend ◽  
Bank Protection ◽  
Three Dimensional Models ◽  
Movable Bed

A three-dimensional numerical model was used to examine the turbulent flow field and associated sediment transport due to a series of barbs (submerged groynes) in a channel bend. Model results were in good agreement with measured laboratory data and adequately simulated the important features of sediment transport. Statistical comparison of the predicted and measured equilibrium bed geometry found average regression coefficients of determination of 0.77 and 0.72 for the 90° and 135° channels, respectively. The predicted velocity data followed expected trends. The capability of a three-dimensional numerical model to simulate sediment transport through bend sections of a channel containing barbs was verified. This included the simulation of the effects of different arrangements of barb groups and an analysis of the data to determine the relation of the flow field to associated scour and deposition in a complex fluvial environment. These novel results are useful for improved analyses of the bank-protection capabilities of these structures and for the development and improvement of design guidelines.Key words: three-dimensional models, numerical models, movable bed models, channel bends, turbulence, secondary flow, scour, barbs, groynes.

scholarly journals Accelerated Time and High-Resolution 3D Modeling of the Flow and Dispersion of Noxious Substances over a Gigantic Urban Area—The EMERGENCIES Project

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 640
Author(s):  
Olivier Oldrini ◽  
Patrick Armand ◽  
Christophe Duchenne ◽  
Sylvie Perdriel ◽  
Maxime Nibart
Keyword(s):  
High Resolution ◽  
Urban Area ◽  
3D Modeling ◽  
Three Dimensional ◽  
Hazardous Materials ◽  
Support Tool ◽  
On Demand ◽  
Simulation Domain ◽  
Dimensional Simulation ◽  
Atmospheric Release

Accidental or malicious releases in the atmosphere are more likely to occur in built-up areas, where flow and dispersion are complex. The EMERGENCIES project aims to demonstrate the operational feasibility of three-dimensional simulation as a support tool for emergency teams and first responders. The simulation domain covers a gigantic urban area around Paris, France, and uses high-resolution metric grids. It relies on the PMSS modeling system to model the flow and dispersion over this gigantic domain and on the Code_Saturne model to simulate both the close vicinity and the inside of several buildings of interest. The accelerated time is achieved through the parallel algorithms of the models. Calculations rely on a two-step approach: the flow is computed in advance using meteorological forecasts, and then on-demand release scenarios are performed. Results obtained with actual meteorological mesoscale data and realistic releases occurring both inside and outside of buildings are presented and discussed. They prove the feasibility of operational use by emergency teams in cases of atmospheric release of hazardous materials.

Assessment of Unsteady Flows in Turbines

1992 ◽  
Vol 114 (1) ◽  
pp. 79-90 ◽  
Author(s):  
O. P. Sharma ◽  
G. F. Pickett ◽  
R. H. Ni
Keyword(s):  
Unsteady Flow ◽  
Three Dimensional ◽  
Flow Simulation ◽  
Experimental Investigations ◽  
Flow Parameters ◽  
Research Activities ◽  
Flow Features ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Design ◽  
The Impact

The impacts of unsteady flow research activities on flow simulation methods used in the turbine design process are assessed. Results from experimental investigations that identify the impact of periodic unsteadiness on the time-averaged flows in turbines and results from numerical simulations obtained by using three-dimensional unsteady Computational Fluid Dynamics (CFD) codes indicate that some of the unsteady flow features can be fairly accurately predicted. Flow parameters that can be modeled with existing steady CFD codes are distinguished from those that require unsteady codes.

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