A layer-integrated approach for shallow water free-surface flow computation

2007 ◽  
Vol 24 (12) ◽  
pp. 1699-1722
Author(s):  
Meng-Chi Hung ◽  
Te-Yung Hsieh ◽  
Tung-Lin Tsai ◽  
Jinn-Chuang Yang
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Free Surface Flow ◽  
Integrated Approach ◽  
Surface Flow ◽  
Flow Computation

Multiphase modeling of the free surface flow through a Darrieus horizontal axis shallow-water turbine

2019 ◽  
Vol 143 ◽  
pp. 1890-1901 ◽  
Author(s):  
Alla Eddine Benchikh Le Hocine ◽  
R.W. Jay Lacey ◽  
Sébastien Poncet
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Horizontal Axis ◽  
Multiphase Modeling ◽  
Water Turbine ◽  
Flow Through

Meshless method for shallow water equations with free surface flow

2011 ◽  
Vol 217 (11) ◽  
pp. 5113-5124 ◽  
Author(s):  
M. Darbani ◽  
A. Ouahsine ◽  
P. Villon ◽  
H. Naceur ◽  
H. Smaoui
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Shallow Water Equations ◽  
Meshless Method ◽  
Free Surface Flow ◽  
Surface Flow

3D free-surface flow computation using a RANSE/Fourier-Kochin coupling

2003 ◽  
Vol 43 (3) ◽  
pp. 301-318 ◽  
Author(s):  
Pierre-Emmanuel Guillerm ◽  
Bertrand Alessandrini
Keyword(s):  
Free Surface ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Flow Computation

scholarly journals PREDICTION OF FREE SURFACE FLOW ON CONTAINMENT FLOOR USING A SHALLOW WATER EQUATION SOLVER

2009 ◽  
Vol 41 (8) ◽  
pp. 1045-1052
Author(s):  
Young-Seok Bang ◽  
Gil-Soo Lee ◽  
Byung-Gil Huh ◽  
Deog-Yeon Oh ◽  
Sweng-Woong Woo
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Shallow Water Equation ◽  
Free Surface Flow ◽  
Surface Flow

Spilling breakers in shallow water: applications to Favre waves and to the shoaling and breaking of solitary waves

2016 ◽  
Vol 808 ◽  
pp. 441-468 ◽  
Author(s):  
S. L. Gavrilyuk ◽  
V. Yu. Liapidevskii ◽  
A. A. Chesnokov
Keyword(s):  
Experimental Data ◽  
Free Surface ◽  
Shallow Water ◽  
Froude Number ◽  
Fluid Velocity ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Undular Bore ◽  
Characteristic Wavelength ◽  
Good Agreement

A two-layer long-wave approximation of the homogeneous Euler equations for a free-surface flow evolving over mild slopes is derived. The upper layer is turbulent and is described by depth-averaged equations for the layer thickness, average fluid velocity and fluid turbulent energy. The lower layer is almost potential and can be described by Serre–Su–Gardner–Green–Naghdi equations (a second-order shallow water approximation with respect to the parameter $H/L$, where $H$ is a characteristic water depth and $L$ is a characteristic wavelength). A simple model for vertical turbulent mixing is proposed governing the interaction between these layers. Stationary supercritical solutions to this model are first constructed, containing, in particular, a local turbulent subcritical zone at the forward slope of the wave. The non-stationary model was then numerically solved and compared with experimental data for the following two problems. The first one is the study of surface waves resulting from the interaction of a uniform free-surface flow with an immobile wall (the water hammer problem with a free surface). These waves are sometimes called ‘Favre waves’ in homage to Henry Favre and his contribution to the study of this phenomenon. When the Froude number is between 1 and approximately 1.3, an undular bore appears. The characteristics of the leading wave in an undular bore are in good agreement with experimental data by Favre (Ondes de Translation dans les Canaux Découverts, 1935, Dunod) and Treske (J. Hydraul Res., vol. 32 (3), 1994, pp. 355–370). When the Froude number is between 1.3 and 1.4, the transition from an undular bore to a breaking (monotone) bore occurs. The shoaling and breaking of a solitary wave propagating in a long channel (300 m) of mild slope (1/60) was then studied. Good agreement with experimental data by Hsiao et al. (Coast. Engng, vol. 55, 2008, pp. 975–988) for the wave profile evolution was found.

scholarly journals An Artificial Compressibility Method for 1D Simulation of Open-Channel and Pressurized-Pipe Flow

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1727
Author(s):  
Ben R. Hodges
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Shallow Water Equation ◽  
Network Models ◽  
Mass Conservation ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Artificial Compressibility ◽  
Piping Systems ◽  
New Formulation

Piping systems (e.g., storm sewers) that transition between free-surface flow and surcharged flow are challenging to model in one-dimensional (1D) networks as the continuity equation changes from hyperbolic to elliptic as the water surface reaches the pipe ceiling. Previous network models are known to have poor mass conservation or unpredictable convergence behavior at such transitions. To address this problem, a new algorithm is developed for simulating unsteady 1D flow in closed conduits with both free-surface and surcharged flow. The shallow-water (hydrostatic) approximation is used as the governing equations. The artificial compressibility (AC) method is implemented as a dual-time-stepping discretization for a finite-volume solver with timescale interpolation used for face reconstruction. A new formulation for the AC celerity parameter is proposed such that the AC celerity matches the equivalent gravity wave speed for the local hydraulic head—which has some similarities to the classic Preissmann Slot used to approximate pressurized flow in conduits. The new approach allows the AC celerity to be set locally by the flow (i.e., non-uniform in space) and removes it as a free parameter of the AC solution method. The derivation of the AC method provides for only a minor change in the form of the solution equations when a computational element switches from free-surface to surcharged. The new solver is tested for both unsteady free-surface (supercritical, subcritical) and surcharged flow transitions in a circular pipe and is implemented in an open-source Python code available under the name “PipeAC.” The results are compared to laboratory experiments that include rapid flow changes due to opening/closing of gates. Results show that the new algorithm is satisfactory for 1D representation of unsteady transition behavior with two caveats: (i) sufficient grid resolution must be applied, and (ii) the shallow-water equation approximations (hydrostatic, single-fluid) limit the accuracy of the solution with regards to the celerity of the turbulent unsteady bore that propagates upstream. This research might benefit any piping network model that must smoothly handle unsteady transitions from free surface to surcharged flow.

scholarly journals Analysis of hull resistance of pushed barges in shallow water

2007 ◽  
Vol 14 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Tomasz Tabaczek ◽  
Jan Kulczyk ◽  
Maciej Zawiślak
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Viscous Liquid ◽  
Water Flow ◽  
Computer Software ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Numerical Calculations

Analysis of hull resistance of pushed barges in shallow water These authors performed a set of numerical calculations of water flow around pushed barges differing to each other by bow forms. The calculations were executed by means of FLUENT computer software. Turbulent free-surface flow of viscous liquid was considered. In this paper the calculated values of barge hull resistance split into bow, cylindrical and stern part components, have been compared and presented.

Numerical Computations for a Nonlinear Free Surface Problem in Shallow Water

2002 ◽  
Author(s):  
K. J. Bai ◽  
J. H. Kyoung ◽  
J. W. Kim
Keyword(s):  
Free Surface ◽  
Shallow Water ◽  
Flow Problem ◽  
Free Surface Flow ◽  
Surface Flow ◽  
Nonlinear Phenomena ◽  
Local Flow ◽  
Highly Nonlinear ◽  
Nonlinear Free Surface ◽  
Good Agreement

This paper describes a finite element method applied to a nonlinear free surface flow problem for a ship moving in three dimensions. The physical model is taken to simulate the towing tank experimental conditions. The exact nonlinear free-surface flow problem formulated by an initial/boundary value problem is replaced by an equivalent weak formulation. The same problem was considered earlier by Bai, et. al. [1] where some irregularities were observed in the downstream waves and a transom stern ship geometry could not be treated. In the present paper, specifically, three improvements are made from the earlier work. The first improvement is the introduction of the 5-point Chebyshev filtering scheme which eliminates the irregular and saw-toothed waves in the downstream. The second improvement is that now we can treat a transom stern ship geometry. The third improvement is the introduction of a new boundary condition to simulate a dry bottom behind a transom stern ship which is stretched from the free surface to the bottom at a high Froude number. Computations are made for two models. The first model is tested for the generation of the solitons in the upstream and smooth waves in the downstream. The second model is used to compute the generation of a dry bottom behind a transom stern which is one of highly nonlinear phenomena. The results of the first model show a good agreement with previous results for the generation of the solitons. The results of the second model also show a good agreement with the preliminary experimental observation for a dry-bottom, which will be reported in near future. The numerical simulation of the second model can be applied to the local flow behind a sail of a submarine in cruise, a sloshing problem in LNG tankers, and a dam breaking problem. Both computed models are assumed to be in shallow water for simplicity. However, the present numerical method can treat arbitrary water-depth and practical ship geometries.

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