scholarly journals Staggered Conservative Scheme for 2-Dimensional Shallow Water Flows

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 149
Author(s):  
Novry Erwina ◽  
Didit Adytia ◽  
Sri Redjeki Pudjaprasetya ◽  
Toni Nuryaman
Keyword(s):  
Wave Propagation ◽  
Numerical Model ◽  
Solitary Wave ◽  
Shallow Water ◽  
Threshold Value ◽  
Staggered Grid ◽  
Conservative Scheme ◽  
Shallow Water Flows ◽  
Run Up ◽  
N Wave

Simulating discontinuous phenomena such as shock waves and wave breaking during wave propagation and run-up has been a challenging task for wave modeller. This requires a robust, accurate, and efficient numerical implementation. In this paper, we propose a two-dimensional numerical model for simulating wave propagation and run-up in shallow areas. We implemented numerically the 2-dimensional Shallow Water Equations (SWE) on a staggered grid by applying the momentum conserving approximation in the advection terms. The numerical model is named MCS-2d. For simulations of wet–dry phenomena and wave run-up, a method called thin layer is used, which is essentially a calculation of the momentum deactivated in dry areas, i.e., locations where the water thickness is less than the specified threshold value. Efficiency and robustness of the scheme are demonstrated by simulations of various benchmark shallow flow tests, including those with complex bathymetry and wave run-up. The accuracy of the scheme in the calculation of the moving shoreline was validated using the analytical solutions of Thacker 1981, N-wave by Carrier et al., 2003, and solitary wave in a sloping bay by Zelt 1986. Laboratory benchmarking was performed by simulation of a solitary wave run-up on a conical island, as well as a simulation of the Monai Valley case. Here, the embedded-influxing method is used to generate an appropriate wave influx for these simulations. Simulation results were compared favorably to the analytical and experimental data. Good agreement was reached with regard to wave signals and the calculation of moving shoreline. These observations suggest that the MCS method is appropriate for simulations of varying shallow water flow.

scholarly journals Momentum Conservative Schemes for Shallow Water Flows

2014 ◽  
Vol 4 (2) ◽  
pp. 152-165 ◽  
Author(s):  
S. R. Pudjaprasetya ◽  
I. Magdalena
Keyword(s):  
Shallow Water ◽  
Shallow Water Equations ◽  
Dam Break ◽  
Staggered Grid ◽  
Conservative Scheme ◽  
Shallow Water Flows ◽  
Advection Term ◽  
Conservative Approximation ◽  
Run Up ◽  
Good Agreement

AbstractWe discuss the implementation of the finite volume method on a staggered grid to solve the full shallow water equations with a conservative approximation for the advection term. Stelling & Duinmeijer [15] noted that the advection approximation may be energy-head or momentum conservative, and if suitable which of these to implement depends upon the particular flow being considered. The momentum conservative scheme pursued here is shown to be suitable for 1D problems such as transcritical flow with a shock and dam break over a rectangular bed, and we also found that our simulation of dam break over a dry sloping bed is in good agreement with the exact solution. Further, the results obtained using the generalised momentum conservative approximation for 2D shallow water equations to simulate wave run up on a conical island are in good agreement with benchmark experimental data.

scholarly journals Non-breaking and breaking solitary wave run-up

2002 ◽  
Vol 456 ◽  
pp. 295-318 ◽  
Author(s):  
YING LI ◽  
FREDRIC RAICHLEN
Keyword(s):  
Numerical Model ◽  
Solitary Wave ◽  
Wave Breaking ◽  
Ad Hoc ◽  
Mapping Technique ◽  
Breaking Wave ◽  
Good Prediction ◽  
Computational Domain ◽  
Domain Mapping ◽  
Run Up

The run-up of non-breaking and breaking solitary waves on a uniform plane beach connected to a constant-depth wave tank was investigated experimentally and numerically. If only the general characteristics of the run-up process and the maximum run-up are of interest, for the case of a breaking wave the post-breaking condition can be simplified and represented as a propagating bore. A numerical model using this bore structure to treat the process of wave breaking and subsequent shoreward propagation was developed. The nonlinear shallow water equations (NLSW) were solved using the weighted essentially non-oscillatory (WENO) shock capturing scheme employed in gas dynamics. Wave breaking and post-breaking propagation are handled automatically by this scheme and ad hoc terms are not required. A computational domain mapping technique was used to model the shoreline movement. This numerical scheme was found to provide a relatively simple and reasonably good prediction of various aspects of the run-up process. The energy dissipation associated with wave breaking of solitary wave run-up (excluding the effects of bottom friction) was also estimated using the results from the numerical model.

scholarly journals The Lituya Bay landslide-generated mega-tsunami. Numerical simulation and sensitivity analysis

2018 ◽  
Author(s):  
José Manuel González-Vida ◽  
Jorge Macías ◽  
Manuel Jesús Castro ◽  
Carlos Sánchez-Linares ◽  
Marc de la Asunción ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Sensitivity Analysis ◽  
Numerical Model ◽  
Shallow Water ◽  
Extreme Event ◽  
Fluid Model ◽  
Model Parameters ◽  
Water Type ◽  
Bathymetric Data ◽  
Run Up

Abstract. The 1958 Lituya Bay landslide-generated mega-tsunami is simulated using the Landslide-HySEA model, a recently developed finite volume Savage-Hutter Shallow Water coupled numerical model. Two factors are crucial if the main objective of the numerical simulation is to reproduce the maximal run-up, with an accurate simulation of the inundated area and a precise re-creation of the known trimline of the 1958 mega-tsunami of Lituya Bay. First, the accurate reconstruction of the initial slide. Then, the choice of a suitable coupled landslide-fluid model able to reproduce how the energy released by the landslide is transmitted to the water and then propagated. Given the numerical model, the choice of parameters appears to be a point of major importance, this leads us to perform a sensitivity analysis. Based on public domain topo-bathymetric data, and on information extracted from the work of Miller (1960), an approximation of Gilbert Inlet topo-bathymetry was set up and used for the numerical simulation of the mega-event. Once optimal model parameters were set, comparisons with observational data were performed in order to validate the numerical results. In the present work, we demonstrate that a shallow water type of model is able to accurately reproduce such an extreme event as the Lituya Bay mega-tsunami. The resulting numerical simulation is one of the first successful attempts (if not the first) at numerically reproducing in detail the main features of this event in a realistic 3D basin geometry, where no smoothing or other stabilizing factors in the bathymetric data are applied.

A Two-Dimensional Numerical Model for Shallow Water Flows over Variable Topographies

2014 ◽  
Vol 580-583 ◽  
pp. 1793-1798
Author(s):  
Biao Lv ◽  
Shao Xi Li
Keyword(s):  
Numerical Model ◽  
Shallow Water ◽  
Source Term ◽  
Unstructured Grids ◽  
Riemann Solver ◽  
Two Dimensional ◽  
Water Flows ◽  
Shallow Water Flows ◽  
Bed Slope ◽  
Good Agreement

Based on well-balanced Roe’s approximate Riemann solver, a numerical model is developed for the unsteady, two-dimensional, shallow water flow with variable topographies. In this model, an efficient methods are applied to treat the source terms and to satisfy the compatibility condition on unstructured grids. In the method, different components of the bed slope source term are considered separately and the compatible discretization of the components is presented. The newly developed model is verified against analytical solutions and measured date, with good agreement.

scholarly journals Evolution of solitary waves and undular bores in shallow-water flows over a gradual slope with bottom friction

2007 ◽  
Vol 585 ◽  
pp. 213-244 ◽  
Author(s):  
G. A. EL ◽  
R. H. J. GRIMSHAW ◽  
A. M. KAMCHATNOV
Keyword(s):  
Solitary Wave ◽  
Shallow Water ◽  
Solitary Waves ◽  
Periodic Wave ◽  
Local Effect ◽  
Bottom Friction ◽  
Undular Bore ◽  
Shallow Water Flows ◽  
Adiabatic Approach ◽  
Variable Topography

This paper considers the propagation of shallow-water solitary and nonlinear periodic waves over a gradual slope with bottom friction in the framework of a variable-coefficient Korteweg–de Vries equation. We use the Whitham averaging method, using a recent development of this theory for perturbed integrable equations. This general approach enables us not only to improve known results on the adiabatic evolution of isolated solitary waves and periodic wave trains in the presence of variable topography and bottom friction, modelled by the Chezy law, but also, importantly, to study the effects of these factors on the propagation of undular bores, which are essentially unsteady in the system under consideration. In particular, it is shown that the combined action of variable topography and bottom friction generally imposes certain global restrictions on the undular bore propagation so that the evolution of the leading solitary wave can be substantially different from that of an isolated solitary wave with the same initial amplitude. This non-local effect is due to nonlinear wave interactions within the undular bore and can lead to an additional solitary wave amplitude growth, which cannot be predicted in the framework of the traditional adiabatic approach to the propagation of solitary waves in slowly varying media.

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