Documents disponibles écrits par cet auteur

An efficient quasi-2D simulation of waterhammer in complex pipe systems / Huan-Feng Duan in Transactions of the ASME . Journal of fluids engineering, Vol. 131 N° 8 (Août 2009) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 8 (Août 2009) . - 09 p. Titre : An efficient quasi-2D simulation of waterhammer in complex pipe systems Type de document : texte imprimé Auteurs : Huan-Feng Duan, Auteur ; Mohamed S. Ghidaoui, Auteur ; Yeou-Koung Tung, Auteur Année de publication : 2009 Article en page(s) : 09 p. Note générale : fluids engineering Langues : Anglais (eng) Mots-clés : pipes;  equations;  simulation;  junctions;  valves;  bifurcation;  boundary-value  problems;  numerical  stability Résumé : An efficient quasi-2D numerical waterhammer model for turbulent waterhammer flows has been previously developed for a single pipe system (reservoir-pipe-valve system). Basic boundary conditions, such as valves, reservoirs, and external flows, were also implemented. This paper extends this previously developed efficient scheme to a general model for a multipipe system. More specifically, an approach for matching the family of characteristic equations in each pipe at a junction of two or more pipes is proposed. In addition, the numerical stability conditions of the efficient scheme are investigated using the Von Neumann method. The resulting model is verified against experimental data and then applied to different complex systems involving pipes in series, branching, and network. Using this model, the effects of unsteady friction in complex pipe systems are examined and analyzed in this paper. From the case studies, it is found that the quasi-2D model is highly efficient, robust, and suitable for application to waterhammer problems in real complex pipe system. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] An efficient quasi-2D simulation of waterhammer in complex pipe systems [texte imprimé] / Huan-Feng Duan, Auteur ; Mohamed S. Ghidaoui, Auteur ; Yeou-Koung Tung, Auteur . - 2009 . - 09 p. fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 131 N° 8 (Août 2009) . - 09 p. Mots-clés : pipes;  equations;  simulation;  junctions;  valves;  bifurcation;  boundary-value  problems;  numerical  stability Résumé : An efficient quasi-2D numerical waterhammer model for turbulent waterhammer flows has been previously developed for a single pipe system (reservoir-pipe-valve system). Basic boundary conditions, such as valves, reservoirs, and external flows, were also implemented. This paper extends this previously developed efficient scheme to a general model for a multipipe system. More specifically, an approach for matching the family of characteristic equations in each pipe at a junction of two or more pipes is proposed. In addition, the numerical stability conditions of the efficient scheme are investigated using the Von Neumann method. The resulting model is verified against experimental data and then applied to different complex systems involving pipes in series, branching, and network. Using this model, the effects of unsteady friction in complex pipe systems are examined and analyzed in this paper. From the case studies, it is found that the quasi-2D model is highly efficient, robust, and suitable for application to waterhammer problems in real complex pipe system. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

Leak detection in complex series pipelines by using the system frequency response method / Huan-Feng Duan in Journal of hydraulic research, Vol. 49 N° 2 (Mars/Avril 2011) 

Public ISBD [article]  in Journal of hydraulic research > Vol. 49 N° 2 (Mars/Avril 2011) . - pp. 213-221 Titre : Leak detection in complex series pipelines by using the system frequency response method Type de document : texte imprimé Auteurs : Huan-Feng Duan, Auteur ; Lee, Pedro J., Auteur ; Mohamed S. Ghidaouic, Auteur Année de publication : 2011 Article en page(s) : pp. 213-221 Note générale : Hydraulique Langues : Anglais (eng) Mots-clés : Complex  series  pipeline  Frequency-response  function  Junction  reflection  Leak  detection  Transient 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 : This research investigates the applicability of the transient-based frequency-response function (FRF) method for detecting leaks in complex series pipelines. The behaviour of transient waves in these pipelines with internal series junctions indicates that junction reflections modify the system resonant frequencies but have a small effect on the leak-induced information contained within the system frequency responses. The analogous method previously developed for single pipelines is extended to complex series pipe systems by using the analytical transfer matrix method herein and the extended method is validated by two simple numerical experimental cases consisting of 3-series pipes and 10-series pipes, respectively. The applied results indicate that the extended FRF method can be applied to detect single and multiple leaks in complex series pipelines as long as the location and size of the resonant peaks of system frequency responses are accurately determined. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.553486 [article] Leak detection in complex series pipelines by using the system frequency response method [texte imprimé] / Huan-Feng Duan, Auteur ; Lee, Pedro J., Auteur ; Mohamed S. Ghidaouic, Auteur . - 2011 . - pp. 213-221. Hydraulique Langues : Anglais (eng) in Journal of hydraulic research > Vol. 49 N° 2 (Mars/Avril 2011) . - pp. 213-221 Mots-clés : Complex  series  pipeline  Frequency-response  function  Junction  reflection  Leak  detection  Transient 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 : This research investigates the applicability of the transient-based frequency-response function (FRF) method for detecting leaks in complex series pipelines. The behaviour of transient waves in these pipelines with internal series junctions indicates that junction reflections modify the system resonant frequencies but have a small effect on the leak-induced information contained within the system frequency responses. The analogous method previously developed for single pipelines is extended to complex series pipe systems by using the analytical transfer matrix method herein and the extended method is validated by two simple numerical experimental cases consisting of 3-series pipes and 10-series pipes, respectively. The applied results indicate that the extended FRF method can be applied to detect single and multiple leaks in complex series pipelines as long as the location and size of the resonant peaks of system frequency responses are accurately determined. DEWEY : 627 ISSN : 0022-1686 En ligne : http://www.tandfonline.com/doi/abs/10.1080/00221686.2011.553486