Weakly undular hydraulic jump: Effects of friction
The undular hydraulic jump is a transitional flow phenomenon where both streamline curvature and frictional effects are important. In the past, streamline curvature effects were treated with the Boussinesq equations for the potential flow approach, thereby overlooking the real flow features. If friction is included, additional terms appear, because the specific energy variation along the undular jump is related to the boundary shear stress. However, these effects are neither addressed in the literature, nor compared with the classical Boussinesq-type solutions. Also, neither information on how boundary layer methods for adverse pressure gradients behave in undular flows is available, nor experimental data. Herein the frictional effects on the Boussinesq equations are systematically analysed using boundary layer methods for adverse pressure gradients. Based on these results, a new simplified approach is proposed to reasonably reproduce the oscillatory boundary layer characteristics in weakly undular hydraulic jumps under a steadily changing pressure gradient from adverse to favourable, and vice versa. © 2010 International Association for Hydro-Environment Engineering and Research.
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International Association of Hydraulic Engineering and Research
2010
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Subjects: | Boundary layer, Undular flow, Transitional flow, Turbulence, Hydraulic jump, |
Online Access: | http://hdl.handle.net/10261/94916 |
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dig-ias-es-10261-949162016-02-17T22:40:34Z Weakly undular hydraulic jump: Effects of friction Castro-Orgaz, Óscar Boundary layer Undular flow Transitional flow Turbulence Hydraulic jump The undular hydraulic jump is a transitional flow phenomenon where both streamline curvature and frictional effects are important. In the past, streamline curvature effects were treated with the Boussinesq equations for the potential flow approach, thereby overlooking the real flow features. If friction is included, additional terms appear, because the specific energy variation along the undular jump is related to the boundary shear stress. However, these effects are neither addressed in the literature, nor compared with the classical Boussinesq-type solutions. Also, neither information on how boundary layer methods for adverse pressure gradients behave in undular flows is available, nor experimental data. Herein the frictional effects on the Boussinesq equations are systematically analysed using boundary layer methods for adverse pressure gradients. Based on these results, a new simplified approach is proposed to reasonably reproduce the oscillatory boundary layer characteristics in weakly undular hydraulic jumps under a steadily changing pressure gradient from adverse to favourable, and vice versa. © 2010 International Association for Hydro-Environment Engineering and Research. The author was supported by a contract of modality JAE-DOC of the programme “Junta para la Ampliación de Estudios”, CSIC, National Research Council of Spain, co-financed by the FSE. CSIC, National Research Council of Spain Peer Reviewed 2014-04-03T12:53:13Z 2014-04-03T12:53:13Z 2010 2014-04-03T12:53:13Z artículo http://purl.org/coar/resource_type/c_6501 doi: 10.1080/00221686.2010.491646 issn: 0022-1686 e-issn: 1814-2079 Journal of Hydraulic Research 48(4): 453-465 (2010) http://hdl.handle.net/10261/94916 10.1080/00221686.2010.491646 none International Association of Hydraulic Engineering and Research |
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Boundary layer Undular flow Transitional flow Turbulence Hydraulic jump Boundary layer Undular flow Transitional flow Turbulence Hydraulic jump |
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Boundary layer Undular flow Transitional flow Turbulence Hydraulic jump Boundary layer Undular flow Transitional flow Turbulence Hydraulic jump Castro-Orgaz, Óscar Weakly undular hydraulic jump: Effects of friction |
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The undular hydraulic jump is a transitional flow phenomenon where both streamline curvature and frictional effects are important. In the past, streamline curvature effects were treated with the Boussinesq equations for the potential flow approach, thereby overlooking the real flow features. If friction is included, additional terms appear, because the specific energy variation along the undular jump is related to the boundary shear stress. However, these effects are neither addressed in the literature, nor compared with the classical Boussinesq-type solutions. Also, neither information on how boundary layer methods for adverse pressure gradients behave in undular flows is available, nor experimental data. Herein the frictional effects on the Boussinesq equations are systematically analysed using boundary layer methods for adverse pressure gradients. Based on these results, a new simplified approach is proposed to reasonably reproduce the oscillatory boundary layer characteristics in weakly undular hydraulic jumps under a steadily changing pressure gradient from adverse to favourable, and vice versa. © 2010 International Association for Hydro-Environment Engineering and Research. |
format |
artículo |
topic_facet |
Boundary layer Undular flow Transitional flow Turbulence Hydraulic jump |
author |
Castro-Orgaz, Óscar |
author_facet |
Castro-Orgaz, Óscar |
author_sort |
Castro-Orgaz, Óscar |
title |
Weakly undular hydraulic jump: Effects of friction |
title_short |
Weakly undular hydraulic jump: Effects of friction |
title_full |
Weakly undular hydraulic jump: Effects of friction |
title_fullStr |
Weakly undular hydraulic jump: Effects of friction |
title_full_unstemmed |
Weakly undular hydraulic jump: Effects of friction |
title_sort |
weakly undular hydraulic jump: effects of friction |
publisher |
International Association of Hydraulic Engineering and Research |
publishDate |
2010 |
url |
http://hdl.handle.net/10261/94916 |
work_keys_str_mv |
AT castroorgazoscar weaklyundularhydraulicjumpeffectsoffriction |
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1777663026688688128 |