Documents disponibles écrits par cet auteur

Artificial stationary breaking surf waves in a physical and numerical model / Mario Oertel in Journal of hydraulic research, Vol. 50 N° 3 (Mai/Juin 2012) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 50 N° 3 (Mai/Juin 2012) . - pp. 338-343 Titre : Artificial stationary breaking surf waves in a physical and numerical model Type de document : texte imprimé Auteurs : Mario Oertel, Auteur ; Jan Mönkemöller, Auteur ; Andreas Schlenkhoff, Auteur Année de publication : 2012 Article en page(s) : pp. 338-343 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Artificial  stationary  surf  wave  Breaking  wave  Numerical  model  Physical  model  Tube  length  VOF Résumé : Surfing is one of the most popular water sports. A number of regional coastal hotspots have naturally breaking surf waves, but wave heights and breaking processes depend on various boundary conditions like seabed geometry, beach formation and swell direction. Since the optimum combination of these conditions is rare in time and place, the formation of surfable waves cannot be guaranteed. In addition, the sport's popularity is currently rising even in inland regions, and with it the interest in generating artificial surf waves in rivers or technical constructions to provide surfable waves at any time and place. This research focuses on small-scale surf waves in a physical and numerical model to identify easy-to-handle geometries and to validate numerical simulations as a low-cost solution for varying boundary conditions. Breaking heights and generated tube lengths are analysed for various geometrical and hydraulic conditions to find set-ups for the creation of stationary breaking waves. En ligne : http://www.tandfonline.com/doi/full/10.1080/00221686.2012.672831 [article] Artificial stationary breaking surf waves in a physical and numerical model [texte imprimé] / Mario Oertel, Auteur ; Jan Mönkemöller, Auteur ; Andreas Schlenkhoff, Auteur . - 2012 . - pp. 338-343. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 50 N° 3 (Mai/Juin 2012) . - pp. 338-343 Mots-clés : Artificial  stationary  surf  wave  Breaking  wave  Numerical  model  Physical  model  Tube  length  VOF Résumé : Surfing is one of the most popular water sports. A number of regional coastal hotspots have naturally breaking surf waves, but wave heights and breaking processes depend on various boundary conditions like seabed geometry, beach formation and swell direction. Since the optimum combination of these conditions is rare in time and place, the formation of surfable waves cannot be guaranteed. In addition, the sport's popularity is currently rising even in inland regions, and with it the interest in generating artificial surf waves in rivers or technical constructions to provide surfable waves at any time and place. This research focuses on small-scale surf waves in a physical and numerical model to identify easy-to-handle geometries and to validate numerical simulations as a low-cost solution for varying boundary conditions. Breaking heights and generated tube lengths are analysed for various geometrical and hydraulic conditions to find set-ups for the creation of stationary breaking waves. En ligne : http://www.tandfonline.com/doi/full/10.1080/00221686.2012.672831

Drag coefficients of boulders on a block ramp due to interaction processes / Mario Oertel in Journal of hydraulic research, Vol. 49 N° 3 (Mai/Juin 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 3 (Mai/Juin 2011) . - pp. 372-377 Titre : Drag coefficients of boulders on a block ramp due to interaction processes Type de document : texte imprimé Auteurs : Mario Oertel, Auteur ; Svenja Peterseim, Auteur ; Andreas Schlenkhoff, Auteur Année de publication : 2011 Article en page(s) : pp. 372-377 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Block  ramp  Boulder  Drag  coefficient  Drag  force  Energy  dissipation  Rough  ramp 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 : Block ramps are a common natural solution for bypassing large steps in riverbeds. The energy dissipation on these ramps was dealt with to develop formulas describing the hydraulic processes. Currently there are no detailed investigations available analysing the resulting forces for boulders on the ramp, although knowledge of these forces is necessary to guarantee an accurate and appropriate design. An investigation programme using a physical model was therefore conducted to describe the effect of boulder interaction processes with respect to forces and drag coefficients. The variable drag coefficients received a special focus because these influence the determination of mean water levels, mean velocities and forces on a single boulder. The physical model allows variation of both discharges and boulder arrangements. As a measurement technique, ultrasonic sensors and load cells were used to determine water levels and drag forces directly. New formulas for Reynolds number-dependent drag coefficients are developed. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.565695 [article] Drag coefficients of boulders on a block ramp due to interaction processes [texte imprimé] / Mario Oertel, Auteur ; Svenja Peterseim, Auteur ; Andreas Schlenkhoff, Auteur . - 2011 . - pp. 372-377. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 3 (Mai/Juin 2011) . - pp. 372-377 Mots-clés : Block  ramp  Boulder  Drag  coefficient  Drag  force  Energy  dissipation  Rough  ramp 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 : Block ramps are a common natural solution for bypassing large steps in riverbeds. The energy dissipation on these ramps was dealt with to develop formulas describing the hydraulic processes. Currently there are no detailed investigations available analysing the resulting forces for boulders on the ramp, although knowledge of these forces is necessary to guarantee an accurate and appropriate design. An investigation programme using a physical model was therefore conducted to describe the effect of boulder interaction processes with respect to forces and drag coefficients. The variable drag coefficients received a special focus because these influence the determination of mean water levels, mean velocities and forces on a single boulder. The physical model allows variation of both discharges and boulder arrangements. As a measurement technique, ultrasonic sensors and load cells were used to determine water levels and drag forces directly. New formulas for Reynolds number-dependent drag coefficients are developed. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.565695

Initial stage of two-dimensional dam-break waves: laboratory versus VOF / Mario Oertel in Journal of hydraulic research, Vol. 50 N° 1 (Janvier/Février 2012) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 50 N° 1 (Janvier/Février 2012) . - pp. 89-97 Titre : Initial stage of two-dimensional dam-break waves: laboratory versus VOF Type de document : texte imprimé Auteurs : Mario Oertel, Auteur ; Daniel B. Bung, Auteur Année de publication : 2012 Article en page(s) : pp. 89-97 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Dam-break  Drag  force  Numerical  model  Physical  model  PIV  VOF Résumé : Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.639981 [article] Initial stage of two-dimensional dam-break waves: laboratory versus VOF [texte imprimé] / Mario Oertel, Auteur ; Daniel B. Bung, Auteur . - 2012 . - pp. 89-97. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 50 N° 1 (Janvier/Février 2012) . - pp. 89-97 Mots-clés : Dam-break  Drag  force  Numerical  model  Physical  model  PIV  VOF Résumé : Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.639981