Wave resonance

from Wikipedia, the free encyclopedia
Storm wave resonances

In coastal engineering, wave resonance is the interaction of wind-generated gravity waves with partially standing waves in a basin formation, which then come into resonance .

The existence of partially closed basins can have different causes. In particular, reef formations in the coastal area come into consideration. The extent of the wave resonance is not only dependent on the energy of the exciting wave spectrum , but also on the shape of the pool formation.

In the case of storm wave resonances, the formation of sand reefs parallel to the coast (sand banks) cannot only be classified as advantageous with regard to the protection of the coasts behind - for example due to the conversion of the energy of breaking waves on the reef or wave energy reflected from the reef seaward.

Rather, in this case the water mass that can oscillate between the sand reef and the beach acts as a resonator . This is capable of executing different natural oscillations in the form of partially standing waves and takes energy from the spectrum of the exciting waves coming over the reef ( forced oscillation ). As a result, increased water level deflections must occur at the edges of the pool - prominent on the beach and weakened on the reef - which can lead to an increased coastal attack, especially due to the formation of heavy surf .

In analogy to the resonant absorption of wave or particle radiation by microphysical systems, wave resonances are also associated with the phenomenon of anomalous dispersion . Since this proves the dominance of the proportion of partially standing waves over that of gravity waves, a calculation on the basis of (non-linear) theories for advancing waves is not possible.

See also

literature

  • Fritz Büsching: Storm wave resonance on the west coast of the island of Sylt , In: The coast, Heft 67, 2003, pp.51- 82.
  • Fritz Büsching: Storm Wave Resonance Controlled by Hollow Block Structures , In: COPEDEC VI, Colombo, Sri Lanka, 2003; Book of Abstracts: “Hollow Blocks for the Protection of a Ridge Coast” p.179-180, CD Proceedings: Paper No.90 p.1-20.

Web links