Analyzing models to predict the wave overtopping of a WEC or seawall

Analyzing models to predict the wave overtopping of a WEC or seawall

At WCWI, we are exploring numerous different numerical and experimental methods of understanding waves and wave energy converters (WEC). However, one of our cutting edge research avenues is exploring the complex joint interactions between waves and WEC’s. Think about it this way:

  1. A wave hits a WEC and excites the WEC to start moving.

  2. As the WEC begins moving, it starts to create its own radiated waves.

  3. The WEC-radiated waves interact constructively and negatively with the incoming waves.

  4. The combination of WEC-radiated and incoming waves now impinges on the WEC and influences its movement.

  5. And the cycle starts again…

As a result, fluid-structure (read: wave-WEC) interactions are of significance to many engineering applications. The hydrodynamic interaction between the waves and WEC’s, as well as the deformation of the free surface (read: sea surface), involves complex physical phenomenon such as air entrainment and turbulence. In order to resolve complex flow phenomenon under extreme ocean conditions, novel emerging numerical methods such as Smoothed Particle Hydrodynamics (SPH) can prove to be alternative to traditional numerical simulations.

Recently, Lagrangian meshless particle methods such as SPH have become an alternative to conventional Eulerian mesh-based methods. SPH has been applied to free surface simulation problems for almost two decades. Incompressible fluids in SPH can be modelled either by relating the fluid pressure to particle density by using a stiff equation of state, or by solving Poisson’s equation to determine the pressure; the two methods are known as weakly compressible SPH (WCSPH) and incompressible SPH (ISPH), respectively.

Here at WCWI, we are comparing the performance of three methods; Incompressible smoothed particle hydrodynamics (SPH), weekly compressible SPH (WCSPH) and previous numerical models to predict the wave overtopping of a WEC or seawall. These initial results will be published in an upcoming conference. Keep an eye on the website for details on where and when we will be presenting these results.