Numerical study of wave conditions for the old Venetian harbor of Chania in Crete, Greece

Maria Kazolea, Nikos Kalligeris, Nikos Maravelakis, Costas Synolakis, Argiris Delis, Patrick Lynett

Friday 3 july 2015

14:15 - 14:30h at Oceania (level 0)

Themes: (T) Water engineering, (ST) Computational methods

Parallel session: 16D. Engineering - Computational

The Venetian harbor of Chania is one of the finest monuments of the island of Crete in Greece and plays an important role in the economical and social life of the island. The harbor’s entrance has been left exposed to wave storms that cause flooding and damages to the quay. In this work an extensive numerical study of the wave conditions in the harbor is presented, using the TUCWave code, the COULWAVE code, and field measurements. In the TUCWave code the 2D weakly nonlinear weakly dispersive Boussinesq-type equations of Nwogu (1993) are solved by implementing a novel high-order accurate, in space and time, well- balanced finite volume (FV) numerical method on unstructured triangular meshes. The FV scheme utilizes an approximate Riemann solver, for the advective fluxes, a well-balanced topography source term upwinding and an accurate numerical treatment of moving wet/dry fronts. The dispersion terms in the model equations are discretized using a consistent discretization to the FV framework. High-order spatial accuracy is achieved through a MUSCL-type reconstruction technique and temporal through a strong stability preserving Runge-Kutta time stepping. In the well established COULWAVE code, the 2D fully nonlinear weakly dispersive Boussinesq-type equations of Wei at al. (1995) are solved. The numerical model uses a predictor-corrector scheme to march forward in time and FV/finite differences (FD) to approximate spatial derivatives on structured meshes. It is of fourth order of accuracy, both in space and time. Wave breaking mechanisms and topography friction terms are also incorporated into both models. An extensive comparison of the two models is implemented. Collected field data are used in this study and long wave oscillations, which arise as a result of nonlinear interactions between narrow-banded waves and swell, is investigated.