Environmental Industry

Simulation of a rapidly varied shallow water flow in complex river geometry

Industrial Applications (real-case problem)

Main goal of the project is to establish a benchmark for validating numerical scheme in open channel flow simulation. The river reach selected for the field test is a 2 km section and is located in the province of Quebec (Canada). This river reach was chosen for the complexity of its river flow and for the quality of the field data available. The reach exhibits torrential flow, transition to fluvial condition through a hydraulic jump, complex bed elevation including an island and flood plains.

We present result of a simulation for a rapidly varied shallow water flow in complex river geometry.

Numerical simulation in Open Channel Flow with main application in the production of Hydro-electricity

Project initiated from a collaborative work effort (University-Industry) for cautioning mathematical models in the hydraulics field (hydro-electricity production).

Description

Main goal of the project was to establish a benchmark for validating numerical scheme in open channel flow simulation. The river reach selected for the field test is a 2 km section and is located in the province of Quebec (Canada). This river reach was chosen for the complexity of its river flow and for the quality of the field data available. The reach exhibits torrential flow, transition to fluvial condition through a hydraulic jump, complex bed elevation including an island and flood plains.

Figures below show (from left to right)  

First, cross-section taken along different reference R points showing the strong sharp gradient in the bottom. The next image show the river basin network is represented by an unstructured grid system using six nodes triangular elements which are located to appropriately represent the flow regime. This element has satisfied all the tests of stability and precision for transient and steady state real life flows. Finally, topography map of the 2km river section. This map has been used to produce the network (mesh) and to adjust the bathymetry on the riverbanks. 

Below we present some result of the simulation. Numerical used is Finite Element of Galerkin type.

Simulation Results

References

A Test Field Calibration to Validate Shallow-Water Codes: the Case of the Ste- Marguerite River with AquaDyn”, J. Belanger, M. Carreau and A. Vincent CERCA Technical Report no. R2000-6, September 2000

see article

Simulation 2D d’une section de la riviere Ste-Marguerite” J. Belanger et A.Vincent Contract work under SoftKit Technologies Inc. and CERCA (1995)

Phd Thesis (not completed)

Abstract In the simulation of the flows with strong variations in the bottom topography, it is essential to integrate the discrete representation of each term with an acceptable degree of accuracy and stability. Improper treatment of these terms may lead to great inaccuracies if strong variations of the bottom topography are present. In this context recently published numerical algorithms pertaining to this problem as well as available experimental data have been used for purposes of validation of the present schemes. The case under consideration is well suited to study the influence of the numerical treatment of the pressure and bottom-slope terms, because of the complexity of the flow. I do believe that all forgoing works are particularly useful contributions to the numerical solution of the St-Venant equations and could be used as a benchmark to test new numerical solvers dedicated to flow conditions

PhdThesis