Author(s): Francisco Ramon Andres Martin; David Lopez Gomez

Linked Author(s): David López Gómez

Keywords: Hybrid; Numerical; Physical; Modeling; SPH

Abstract: Spain is a country with a large number of old dams and, therefore, it is very important to check the hydraulic performance of its drainage structures, both to adjust them to the new regulations and to detect possible malfunctions through the use of much more advanced and precise tools than those existing at the time of its original design. Currently, the Hydraulic Laboratory of CEDEX is carrying out the hydraulic study of the spillway of the Pálmaces dam, whose inauguration dates back to 1954, although the spillway works ended in 1964. Hybrid modeling is being used for its analysis, combining physical modeling with a 1/40 reduced scale model and numerical modeling, in this case mainly three-dimensional. For the three-dimensional numerical models, the SPHerimental software, developed entirely by CEDEX, is being used. It implements the SPH method, Smoothed Particle Hydrodynamics, a Lagrangian model of particles that, through an averaging technique, can solve the Navier-Stokes equations for three-dimensional flow. It has been developed using CUDA, which allows to take advantage of the computing power of GPU graphics cards and, consequently, to reduce calculation times considerably and to use supercomputing techniques in cheaper hardware. The pre and post-processing tasks are carried out with GiD and Nayade software. Initially, the spillway has been analyzed with numerical models, detecting possible areas of nappe flow separation or depressions. Subsequently, and continuing with numerical modeling, a solution has been sought with which these problems have been avoided. Finally, that solution is built in the physical model and it is verified that it works correctly. The joint use of numerical modeling and physical modeling makes it possible to take full advantage of both the advantages offered by each of them and the synergies generated by the joint use of both. The numerical one allows to analyze a greater number of possible solutions with a lower cost, in money, resources and time. It also allows to analyze larger geometries. The physical modeling makes it possible to quantify various aspects of the flow with greater precision, such as water levels, pressures on the contour surfaces, etc. At the same time, it allows to observe the behavior of the flow directly. However, where perhaps the most benefit is obtained from the joint use of both models is in aspects such as the possibility of calibrating the numerical models; the use of these ones to achieve a better design of the physical models; or the saving of time, money and resources in general, by being able to carry out a large number of tests on numerical models and leave for the physicals the definitive ones or those that, due to their simplicity, are easier to analyse in this type of model.

DOI: https://doi.org/10.3850/IAHR-39WC2521711920221873

Year: 2022