Poster Alessandro GUERRI

Context

This thesis aims to improve knowledge of the physics and numerical modelling of nonlinear wave-wave interactions from the oceanic domain to the coastal zone, considering the effects of an ambient marine current. Depending on the relative water depth, the dominant interactions occur between 4 or 3 waves; they play a fundamental role in the dynamics of the wave field and control the shape of directional energy spectrum of the sea state (cf. Cavaleri et al. (2007), for example).

These modifications to the spectrum, corresponding to the evolution of wave trains in the physical domain (shape and height of wave troughs and crests, horizontal and vertical asymmetries of the wave profile, presence of long waves, etc.), are fundamental for applications in the maritime and coastal domain.

More accurate prediction methods are essential to control metocean conditions for conducting operations at sea, designing offshore installations and coastal structures, etc.

Conclusions so far

• Key role of 4-waves interactions in sea state dynamics:
  • Formation of spectral peak and 𝑓−4 tail
  • Once near equilibrium spectral shape is reached, shifting of the peak towards lower frequencies
• Discrepancies between quasi-exact GQM and approximate DIA methods

Next steps

Optimization of GQM CPU time (elimination of least important quadruplet configurations, optimal number of integration points, …)

• Extension of GQM algorithm to finite water depth
• Taking into consideration the effect of ambient current