Documents disponibles écrits par cet auteur

Developing flow in skimming flow regime on embankment stepped spillways / Daniel B. Bung in Journal of hydraulic research, Vol. 49 N° 5 (Septembre/Octobre 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 5 (Septembre/Octobre 2011) . - pp. 639-648 Titre : Developing flow in skimming flow regime on embankment stepped spillways Type de document : texte imprimé Auteurs : Daniel B. Bung, Auteur Année de publication : 2011 Article en page(s) : pp. 639-648 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Air–water  flow  Developing  flow  Physical  modelling  Self-aeration  Stepped  spillway 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 : In hydraulic engineering, stepped spillways are effective structures in regard to both energy dissipation and re-aeration processes. It is well known that flow depths and flow velocities generally depend on the spillway geometry in terms of slope and step-induced macro-roughness height on the one hand and the discharge on the other hand. Moreover, these parameters affect the air entrainment process and hence, the amount and the size of entrained air bubbles which are directly linked to the specific air–water interface being of particular significance for oxygen transfer. In this study, physical model investigations on a stepped spillway scaled 1:10 of varying step height, chute angle and discharge are conducted with the objective to analyse the development of these air–water flow properties in the non-uniform flow region. Measurements of air–water mixture velocity and air concentration are carried out by the use of an intrusive double-tip conductivity probe. It is found that the step-induced macro-roughness has a differing effect on particular flow characteristics. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.584372 [article] Developing flow in skimming flow regime on embankment stepped spillways [texte imprimé] / Daniel B. Bung, Auteur . - 2011 . - pp. 639-648. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 5 (Septembre/Octobre 2011) . - pp. 639-648 Mots-clés : Air–water  flow  Developing  flow  Physical  modelling  Self-aeration  Stepped  spillway 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 : In hydraulic engineering, stepped spillways are effective structures in regard to both energy dissipation and re-aeration processes. It is well known that flow depths and flow velocities generally depend on the spillway geometry in terms of slope and step-induced macro-roughness height on the one hand and the discharge on the other hand. Moreover, these parameters affect the air entrainment process and hence, the amount and the size of entrained air bubbles which are directly linked to the specific air–water interface being of particular significance for oxygen transfer. In this study, physical model investigations on a stepped spillway scaled 1:10 of varying step height, chute angle and discharge are conducted with the objective to analyse the development of these air–water flow properties in the non-uniform flow region. Measurements of air–water mixture velocity and air concentration are carried out by the use of an intrusive double-tip conductivity probe. It is found that the step-induced macro-roughness has a differing effect on particular flow characteristics. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.584372

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