Optimisation of hydroelectric power stations operations with WOLF package

For years, original free-surface flow solvers have been developed and continuously improved by the Laboratory of Applied Hydrodynamics and Hydraulic Constructions (HACH) at the University of Liège. The resulting fully integrated WOLF computation package allows engineers to accurately study a very wide range of various free surface flows, from hydrological runoff (WOLF HYDRO) and river propagation (WOLF 1D) to extreme erosive flows on realistic mobile topography (WOLF 2D), such as gradual dam breaching processes.
All the finite volume models, process oriented, use efficient and original numerical methods to solve free surface flows equations. Each code handles general multiblock meshes, dealing with natural topography, dry and wet cells and mobile bed simultaneously, for any unsteady situation with mixed regimes and moving hydraulic jumps. The interactive and unique user-interface, with high performance pre- and post-processing, allows monitoring 3-D large-scale runs graphically while they proceed, as well as generating 3D videos. In addition, powerful optimisation capabilities based on the Genetic Algorithms technique (WOLF AG) are implemented within WOLF, interconnecting all the package components. An efficient tool is thus available to calibrate physical parameters in any of the models and to manage any problem of optimisation with the different solvers.
In this paper, the numerical optimisation process of the system of hydroelectric power stations installed on a 60 km long section of the rivers Amblève and Warche in Belgium is presented in detail. The river network is modelled in quasi-2D using real natural topographic data on almost 1,100 finite volumes. In a first step, the hydrological balance is closed using the solver WOLF HYDRO. Roughness coefficients are calibrated from water level and discharge field measurements. Secondly, the hydroelectric production is maximised by an automatic calibration of the parameters of the hydrograph released in the network at the upstream dam.
This approach leads to a substantial gain in hydroelectric production, brings significant financial benefits and deals with all management and security criteria of the river network.