CFD at Lagrande 1 Power Plant Intake Hydro-Quebec, Quebec, Canada

A three dimensional numerical analysis has been carried out for the La Grande 1 power plant intake for comparison with current meter measurements made by Hydro-Québecs' engineers. The top Figures show the topology of the intake and an overview of the grid used. Various geometric configurations and inlet flow conditions have been studied. The first test was for the original design of the intake. In the second test, because the upstream floor could have been modified over the years by sediment/debris deposits, two other configurations were tested. The third test was conducted by varying the approach flow at the inlet.

The distribution of flow variables such the horizontal velocity is shown in the bottom left Figure. A quantitative comparison with current meter measurements is shown in the bottom right Figure. Assuming the current meter measurements are accurate, the numerical study shows that the geometry of the bottom entrance of the intake is no longer as originally built since the CFD and current meter data do not match around the floor. Indeed, when the configuration at the entrance is modified in the model, the CFD data more closely approach the measurements. This provides strong evidence that the upstream floor configuration has been probably modified by sediment deposits.

Paper presented at IGHEM2004: COMPARISON OF DISCHARGE MEASUREMENT BY CURRENT METER AND ACOUSTIC SCINTILLATION METHODS AT LA GRANDE-1 (452pdf)