EXPERIMENTAL AND NUMERICAL CHARACTERISATION OF A 2D WAVE FLUME

Abstract

A wave flume of 12.5 x 0.6 x 0.7 m (length x width x height) able to reproduce the ocean conditions of the most representative research facilities in the Basque Country (BiMEP-Biscay Marine Energy Platform and Mutriku Wave Energy Plant) has been recently installed at the laboratory of Fluid Mechanics of the Faculty of Engineering in Bilbao. This new facility has the capacity of producing a wide range of monochromatic and panchromatic waves by a piston-type wavemaker. Several ultrasonic wave probes measure the surface elevation, and the wave energy is dissipated in a passive parabolic beach in order to diminish significantly the reflection along the flume. A numerical model based on Reynolds Averaged Navier Stokes (RANS) equations has been developed to represent the turbulence and Eulerian Volume of Fluid (VOF) unsteady approach in STAR-CCM+ CFD code to track the evolution of the free surface. This numerical model has been validated with the corresponding experimental campaign covering a wide range of depths, wave heights, wavelengths and periods. Tests focused on the description of the basic hydrodynamic processes of wave generation and propagation, giving as a result the definition of the wavemaker to produce the required wave. Results were analysed together with the analytical solution based on potential flow theory. The experiments carried out in the present study establish the operational limits of the wave flume in terms of wave generation, propagation and extinction, defining the operational range of future experimental campaigns where wave interaction with floating structures, wave energy converters and mooring systems will be studied. Keywords: experimental wave flume, numerical wave flume validation, wave characterisation, BiMEP, renewable marine energy, CFD models