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Water motion over tidal flats: Finite element method in the frequency domain

ten Napel, Zoë (author)

Tidal flats are important coastal ecosystems that support a diverse range of plants and animals. Accurate prediction of water motion over tidal flats is crucial for the design of coastal infrastructure, hazard assessment, environmental management and oceanography research. Defina [1] derived a new set of shallow water equations that allow for...

master thesis 2023

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Comparison of an Explicit and Implicit Time Integration Method on GPUs for Shallow Water Flows on Structured Grids

Buwalda, F.J.L. (author), de Goede, Erik (author), Knepflé, Maxim (author), Vuik, Cornelis (author)

The accuracy, stability and computational efficiency of numerical methods on central processing units (CPUs) for the depth-averaged shallow water equations were well covered in the literature. A large number of these methods were already developed and compared. However, on graphics processing units (GPUs), such comparisons are relatively scarce....

journal article 2023

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On the Efficiency of Staggered C-Grid Discretization for the Inviscid Shallow Water Equations from the Perspective of Nonstandard Calculus

Zijlema, M. (author)

This paper provides a rationale for the commonly observed numerical efficiency of staggered C-grid discretizations for solving the inviscid shallow water equations. In particular, using the key concepts of nonstandard calculus, we aim to show that the grid staggering of the primitive variables (surface elevation and normal velocity components)...

journal article 2022

document

Boosted robustness of semi-implicit subgrid methods for shallow water flash floods in hills

Stelling, G.S. (author)

The widespread availability of high-resolution Digital Elevation Models (DEM), has led to the development of subgrid numerical modeling techniques, based on Shallow Water Equations (SWE). Detailed DEM data is clustered as much as possible within a coarse grid cell that is preferably much larger than a raster pixel. This has considerable...

journal article 2022

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The application of differentiable programming frameworks to computational fluid dynamics

Vos, Bart (author)

In recent years many automatic differentiable programming frameworks have been developed in which numerical programs can be differentiated through automatic differentiation (AD). Examples of these frameworks are Theano, TensorFlow and Pytorch. These frameworks are widely used in Machine Learning. AD also finds applications in the field of...

bachelor thesis 2021

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A one-way coupled hydrodynamic advection-diffusion model to simulate congested large wood transport

Persi, Elisabetta (author), Petaccia, Gabriella (author), Sibilla, Stefano (author), Bentivoglio, Roberto (author), Armanini, Aronne (author)

An advection-diffusion model is proposed to simulate large wood transport during high flows. The mathematical model is derived from the wood mass balance, taking into consideration both the wood mass concentration and the log orientation, which affects log transport and, most importantly, wood accumulation. Focusing on wood mass transport,...

journal article 2021

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Free and forced components of shoaling long waves in the absence of short-wave breaking

Contardo, Stephanie (author), Lowe, Ryan J. (author), Hansen, Jeff E. (author), Rijnsdorp, D.P. (author), Dufois, François (author), Symonds, Graham (author)

Long waves are generated and transform when short-wave groups propagate into shallow water, but the generation and transformation processes are not fully understood. In this study we develop an analytical solution to the linearized shallow-water equations at the wave-group scale, which decomposes the long waves into a forced solution (a bound...

journal article 2021

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Suitability of Shallow Water Solving Methods for GPU Acceleration

Buwalda, Floris (author)

In the past 15 years the field of general purpose computing on graphics processing units, or GPUs, has become well developed and the practice is becoming more mainstream. Computational demands of simulation software are continuously increasing. As such for many applications traditionally computed on the central processing unit the question...

master thesis 2020

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The role of the Rankine-Hugoniot relations in staggered finite difference schemes for the shallow water equations

Zijlema, M. (author)

The purpose of this work is to point out the relevance of the Rankine-Hugoniot jump relations regarding the numerical solution of the inviscid shallow water equations. To arrive at physically relevant solutions in rapidly varied flow, it is of crucial importance that continuity of mass flux and momentum flux across a steady discontinuity is...

journal article 2019

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A dynamic emulator for physically based flow simulators under varying rainfall and parametric conditions

Moreno Rodenas, A. (author), Bellos, V. (author), Langeveld, J.G. (author), Clemens, F.H.L.R. (author)

This work presents a method to emulate the flow dynamics of physically based hydrodynamic simulators under variations of time-dependent rainfall and parametric scenarios. Although surrogate modelling is often employed to deal with the computational burden of this type of simulators, common techniques used for model emulation as polynomial...

journal article 2018

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Salt marsh modelling: implemented on a GPU

Peeters, Lotte (author)

In this thesis, a coupled hydrodynamic, morphodynamic and plant growth model is reviewed. The goal of this model is to simulate plant colonization and channel formation on an initially flat or ascending substrate in a tidal landscape. To be able to simulate these biophysical processes on a small enough scale (while still using the same spatial...

master thesis 2018

document

Time-varying storm surges on Lorentz’s Wadden Sea networks

Reef, Koen RG (author), Lipari, Giordano (author), Roos, Pieter C. (author), Hulscher, Suzanne J.M.H. (author)

We present an idealized network model for storm surges in the Wadden Sea, specifically including a time-dependent wind forcing (wind speed and direction). This extends the classical work by H.A. Lorentz who only considered the equilibrium response to a steady wind forcing. The solutions obtained in the frequency domain for the linearized shallow...

journal article 2018

document

Shallow water equations for equatorial tsunami waves

Geyer, A. (author), Quirchmayr, Ronald (author)

We present derivations of shallow water model equations of Korteweg–de Vries and Boussinesq type for equatorial tsunami waves in the f-plane approximation and discuss their applicability.

journal article 2018

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Traveling wave solutions of a highly nonlinear shallow water equation

Geyer, A. (author), Quirchmayr, Ronald (author)

Motivated by the question whether higher-order nonlinear model equations, which go beyond the Camassa-Holm regime of moderate amplitude waves, could point us to new types of waves profiles, we study the traveling wave solutions of a quasilinear evolution equation which models the propagation of shallow water waves of large amplitude. The aim of...

journal article 2018

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Particle-driven gravity currents

Stovers, M.J.P. (author)

Gravity currents are common around the world, consider for instance avalanches and pyroclastic flows. The kind of gravity currents that this research focuses on occur below the water surface. During dredging operations soil is cut and transported, during many of these processes sediment is introduced into the environment. Consider for instance...

master thesis 2016

document

Analysis of Tidal Inlet Stability

Guo, L. (author)

The main goal of this project is to predict the in uence of non-uniform basin depths on the stability of single inlet systems. This is achieved by making use of Escoffier's principle, which poses a relationship between the relative water flow velocity in an inlet and the rate of change of its cross-sectional area. To this end, a thorough...

bachelor thesis 2016

document

Salt Dynamics in Well-Mixed Estuaries: Importance of Advection by Tides

Wei, X. (author), Schuttelaars, H.M. (author), Schramkowski, G.P. (author)

Understanding salt dynamics is important to adequately model salt intrusion, baroclinic forcing, and sediment transport. In this paper, the importance of the residual salt transport due to tidal advection in well-mixed tidal estuaries is studied. The water motion is resolved in a consistent way with a width-averaged analytical model, coupled to...

journal article 2016

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A Study of Reduced Order 4D-VAR with a Finite Element Shallow Water Model

Ambrozic, M. (author)

Forecast models often depend on unknown parameters, such as model initial and boundary conditions, or other tunable parameters not necessarily having any physical meaning. Calibration of these parameters to minimize errors between forecasted and observed states is called data assimilation. A common approach in this context are variational...

master thesis 2013

document

A finite volume approach for shallow water flow accounting for high-resolution bathymetry and roughness data

Volp, N.D. (author), Van Prooijen, B.C. (author), Stelling, G.S. (author)

This study presents a finite volume hydrodynamic model for shallow water flow that computes on a coarse grid, but accounts for high-resolution bathymetry and roughness variations on a subgrid. The detailed information can be incorporated by using the assumption of a uniform flow direction and a uniform friction slope within a part of a coarse...

journal article 2013

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Unstructured Orthogonal Meshes for Modeling Coastal and Ocean Flows

Kleptsova, O. (author)

In this thesis a z?layer unstructured C-grid finite volume hydrostatic model is presented. An efficient and highly scalable implicit technique for the solution of the free surface equation is combined with an Eulerian approach for the advection of momentum. A consistent velocity reconstruc- tion procedure which not only satisfies the continuity...

doctoral thesis 2013