Documents disponibles écrits par cet auteur

A Boussinesq-type model incorporating random wave-breaking / Michalis K. Chondros in Journal of hydraulic research, Vol. 49 N° 4 (Juillet/Août 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 4 (Juillet/Août 2011) . - pp. 529-538 Titre : A Boussinesq-type model incorporating random wave-breaking Type de document : texte imprimé Auteurs : Michalis K. Chondros, Auteur ; Iason G. Koutsourelakis, Auteur ; Constantine Demetrius Memos, Auteur Année de publication : 2011 Article en page(s) : pp. 529-538 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Boussinesq  equation  Eddy  viscosity  MIKE21  Numerical  modelling  Surface  roller  Wave-breaking Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : A recent Boussinesq-type model is herein modified to account for breaking waves in shallow water. The model is based on a system of equations in terms of surface elevation and depth-averaged horizontal velocities, in two horizontal dimensions for fully dispersive and weakly nonlinear random waves over any finite water depth. The formulation involves five terms in each momentum equation, including the classical shallow-water equation terms, and only one frequency dispersion term. This work extends the model by including depth-induced wave-breaking in one horizontal dimension, based on the eddy viscosity and surface roller criteria. The modified model was applied to simulate the propagation and wave-breaking of regular and random waves using a simple explicit finite difference scheme. The simulation results were compared with experimental data and with results from one of the most widespread commercial Boussinesq wave models, indicating good agreement in most cases. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.571817 [article] A Boussinesq-type model incorporating random wave-breaking [texte imprimé] / Michalis K. Chondros, Auteur ; Iason G. Koutsourelakis, Auteur ; Constantine Demetrius Memos, Auteur . - 2011 . - pp. 529-538. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 4 (Juillet/Août 2011) . - pp. 529-538 Mots-clés : Boussinesq  equation  Eddy  viscosity  MIKE21  Numerical  modelling  Surface  roller  Wave-breaking Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : A recent Boussinesq-type model is herein modified to account for breaking waves in shallow water. The model is based on a system of equations in terms of surface elevation and depth-averaged horizontal velocities, in two horizontal dimensions for fully dispersive and weakly nonlinear random waves over any finite water depth. The formulation involves five terms in each momentum equation, including the classical shallow-water equation terms, and only one frequency dispersion term. This work extends the model by including depth-induced wave-breaking in one horizontal dimension, based on the eddy viscosity and surface roller criteria. The modified model was applied to simulate the propagation and wave-breaking of regular and random waves using a simple explicit finite difference scheme. The simulation results were compared with experimental data and with results from one of the most widespread commercial Boussinesq wave models, indicating good agreement in most cases. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.571817

Wave attenuation due to Posidonia oceanica meadows / José Francisco Sanchez-Gonzalez in Journal of hydraulic research, Vol. 49 N° 4 (Juillet/Août 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 4 (Juillet/Août 2011) . - pp. 503-514 Titre : Wave attenuation due to Posidonia oceanica meadows Type de document : texte imprimé Auteurs : José Francisco Sanchez-Gonzalez, Auteur ; Virginia Sanchez-Rojas, Auteur ; Constantine Demetrius Memos, Auteur Année de publication : 2011 Article en page(s) : pp. 503-514 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Drag  coefficient  Physical  model  Posidonia  oceanica  Vegetation  field  Wave  damping Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : An experimental study carried out in a flume to a scale of 1/20 is presented to assess the wave height attenuation induced by submerged meadows of Posidonia oceanica. After examination of the appropriate scaling laws and selection of the model material, an extensive test programme included both regular and random waves. A semi-empirical formulation for estimating the wave height transformation along the meadow is obtained, based on energy conservation and considering that dissipation is only due to drag forces. The latter were linearized to obtain an exponential decay law. The formulation proposed depends on the drag coefficient and includes also an empirical parameter accounting for wave steepness. The model improves previous results and extends its applicability to random waves. The drag coefficient associated to the meadows is found to be better related to the Keulegan–Carpenter parameter than to the Reynolds number. Its value is given also for models proposed by others. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.552464 [article] Wave attenuation due to Posidonia oceanica meadows [texte imprimé] / José Francisco Sanchez-Gonzalez, Auteur ; Virginia Sanchez-Rojas, Auteur ; Constantine Demetrius Memos, Auteur . - 2011 . - pp. 503-514. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 4 (Juillet/Août 2011) . - pp. 503-514 Mots-clés : Drag  coefficient  Physical  model  Posidonia  oceanica  Vegetation  field  Wave  damping Index. décimale : 627 Ingénierie des cours d'eau naturels, des ports, des rades et des cotes. Installations de navigation, de dragage, de récupération et de sauvetage. Barrages et centrales électriques hydrauliques Résumé : An experimental study carried out in a flume to a scale of 1/20 is presented to assess the wave height attenuation induced by submerged meadows of Posidonia oceanica. After examination of the appropriate scaling laws and selection of the model material, an extensive test programme included both regular and random waves. A semi-empirical formulation for estimating the wave height transformation along the meadow is obtained, based on energy conservation and considering that dissipation is only due to drag forces. The latter were linearized to obtain an exponential decay law. The formulation proposed depends on the drag coefficient and includes also an empirical parameter accounting for wave steepness. The model improves previous results and extends its applicability to random waves. The drag coefficient associated to the meadows is found to be better related to the Keulegan–Carpenter parameter than to the Reynolds number. Its value is given also for models proposed by others. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.552464