Interactions between numerical and physical modelling for the design and optimization of hydraulic structures - Example of a large hydroelectric complex

This paper describes the successful combination of both physical and numerical modelling
techniques applied to the scale model study of a large hydroelectric complex in India. Thanks to
accurate numerical simulations, the physical model layout and the time to studies have been
drastically reduced.
First, prior to the design of the scale model, a global numerical simulation of the dam
reservoir has been carried out, on the basis of the entire set of available topographic data. The
simulation results supply the flow conditions in the upstream reservoir, particularly in the vicinity
of the dam and the spillway crest.
Subsequently, a second numerical computation has been performed to simulate the flow in a
scale model representing only a small part of the reservoir upstream of the dam. The suitable
correspondence between flow conditions in both cases has been demonstrated.
This two-steps approach has enabled a significant reduction in the size of the scale model,
and hence, a lower cost as well as a shorter delay for building the model. Simultaneously, it has
been possible to decrease the scale factor at constant cost.
In conclusion, the present paper provides convincing evidence that the increase in computers
performance and the efficiency of contemporary free-surface flow solvers lead to useful numerical information for the optimal design and exploitation of scale models.