Estudo numérico de ondas monocromáticas em duas praias e sobre um recife artificial na Baía do Espírito Santo, Vitória, ES

Abstract

Water waves propagating in direction to the coast suffer important deformations, which are important for several processes occurring on the nearshore. Numerical models are used for engineers and oceanographers as tools for study those coastal processes with a small range of error. The interaction of water waves with a body is investigated in this work. Numerical simulations are realized for two cases. In the first case, monochromatic incident waves interact with a complex coastal area and in the second case waves interact with a multifunctional artificial reef. The chosen coastal area is the “Curva da Jurema” and the artificial reef is put near the Camburi's beach, both regions are suffering erosion processes and they are located in Espírito Santo Bay. The numerical simulations are run by using the numeric model FUNWAVE 2.0, based on the Boussinesq-type equations by Wei et al. (1995). The non-uniform computation grid used has typical length from 5m to Curva da Jurema and 1m to the Artificial Reef. In the region of the Curva da Jurema the results of simulation of the incident waves of the Northeast and Southeast quadrant had shown that the waves amplitude are almost that totally dissipated inside of the embayament and it approaches zero close to the beach. The refraction, diffraction and reflection processes of the incident wave with the depth and the coastal boundaries are evidenced, in field wave, and these processes can be responsible for the appearance of a super-harmonic on the wave spectrum proceeding from Southeast. In the section of Camburi’s beach, in which Multifunctional Artificial Reef was placed, the Northeast and Southeast waves reach perpendicularly the beach. Without the reef, the behavior of the waves in this domain if showed influenced for the gradients bathymetric, generating of rip currents and great concentration of energy near to the shoreline. With the installation of the multifunctional artificial reef a reduction of the intensity of energy of wave in the shoreline was verified. The reef was projected with slope and internal angles favorable for generation of surfing waves. The simulations results accomplished with the inclusion of the reef showed that the waves that had propagated on reef are intensified in height until breaking, approximately to a distance of 200m of the shoreline, and propagating towards the shoreline with a smaller energy than that without the reef. Thus, numeric simulations results run with the wave’s model FUNWAVE showed that the model is capable to reproduce the main processes that happen in coastal areas and it can be using as tool for the coastal management.