Accurate vertical profiles of turbulent flow in z-layer models

Three-dimensional hydrodynamic z-layer models, which are used for simulating the flow in rivers, estuaries, and oceans, suffer from an inaccurate and often discontinuous bottom shear stress representation, due to the staircase bottom. We analyze the governing equations and clearly show the cause of the inaccuracies. Based on the analysis, we...

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

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...

A numerical study of mixing and stratification dynamics in the Ria de Arousa estuary (nw Spain) during summer

In this paper we explore the role of the river run-off, the tidal regime and the local winds in the dynamics of the Ria de Arousa estuary during the summer period, using for that purpose the numerical model Delft3D. First of all, a simulation under real hydrological and meteorological conditions is conducted in order to validate the ability of...

Development and field validation of a 2DH curvilinear storm impact model

The formulations of the 2DH process-based, nearshore morphological model XBeach were extended to allow for curvilinear grids using a finite volume approach. The formulations were tested for schematic cases such as a circular island and a field validation study was carried out for the case of storm erosion during a construction phase of the soft...

Simulating nearshore wave transformation with non-hydrostatic wave-flow modelling

Efficient scheme for the shallow water equations on unstructured grids with application to the Continental Shelf

In this paper, a shallow-water flow solver is presented, based on the finite-volume method on unstructured grids The method is suitable for flows that occur in rivers, channels, sewer systems (1D), shallow seas, rivers, overland flow (2D), and estuaries, lakes and shelf breaks (3D). We present an outline of the numerical approach and show three...

An accurate momentum advection scheme for a z-level coordinate models

In this paper, we focus on a conservative momentum advection discretisation in the presence of zlayers. While in the 2Dcase conservation ofmomentum is achieved automatically for an Eulerian advection scheme, special attention is required in the multi-layer case. We show here that an artificial vertical structure of the flow can be introduced...

A streamline tracking algorithm for semi-Lagrangian advection schemes based on the analytic integration of the velocity field

A new scheme for the construction on an unstructured grid of the streamlines of the three-dimensional shallow water equations is presented. The qualitative advantages of the scheme, notably closed streamlines and realistic treatment of closed boundaries, are derived and the spatial accuracy is demonstrated. Semi-Lagrangian advection schemes...

Computational modelling flow and transport

Lecture notes CT wa4340. Derivation of equations using balance principles; numerical treatment of ordinary differential equations; time dependent partial differential equations; the strucure of a computer model:DUFLO; usage of numerical models.

Efficiënt berekenen van vertikale strukturen

Bij het oplossen van vragen over de morfodynamische processen die zich voor de kust afspelen, is inzicht in de dynamiek van vooroever en brandingsruggen onontbeerlijk. Een instrument dat hierbij aan bij kan dragen is het ARGUS videosysteem dat in het kader van het KUST*2000 onderzoekprogramma bij Bergen Egmond zal worden opgesteld. Een...

Experiments and computations on unsteady separating flow in an expanding flume

An unsteady, separating flow with a free surface was investigated with a physical model and a numerical model. To simulate tidal flow, the prescribed flow rate at the inflow boundary was a half-period sine function of time. Measurements of velocities and wave heights were conducted by using LDV and a wave-height meter in a straight open channel...