TY - CHAP A1 - Valero, Daniel A1 - Bung, Daniel B. T1 - Interfacial velocity estimation in highly aerated stepped spillway flows with a single tip fibre optical probe and Artificial Neural Networks T2 - 6th IAHR International Junior Researcher and Engineer Workshop on Hydraulic Structures, May 30th to June 1st 2016. Lübeck, Germany N2 - Air-water flows can be found in different engineering applications: from nuclear engineering to huge hydraulic structures. In this paper, a single tip fibre optical probe has been used to record high frequency (over 1 MHz) phase functions at different locations of a stepped spillway. These phase functions have been related to the interfacial velocities by means of Artificial Neural Networks (ANN) and the measurements of a classical double tip conductivity probe. Special attention has been put to the input selection and the ANN dimensions. Finally, ANN have shown to be able to link the signal rising times and plateau shapes to the air-water interfacial velocity. Y1 - 2016 U6 - http://dx.doi.org/10.15142/T3Q590 ER - TY - CHAP A1 - Feldmann, M. A1 - Döring, Bernd A1 - Pyschny, D. T1 - Floor systems; Sustainabilty analyses and assessments of steel bridges T2 - Sustainable steel buildings : a practical guide for structures and envelopes Y1 - 2016 SN - 978-1-118-74079-8 (PDF) SN - 978-1-118-74111-5 SP - 198 EP - 223 PB - Wiley Blackwell CY - Chichester, West Sussex ER - TY - BOOK A1 - Bleninger, T. A1 - Brenda, M. A1 - Bung, Daniel B. A1 - Hengl, M. A1 - Schmid, B.H. A1 - Schneider, E. A1 - Sonnenburg, A. A1 - Stoschek, O. T1 - DWA-Regelwerk M 544-2 : Merkblatt: Ausbreitungsprobleme von Einleitungen - Prozesse, Methoden und Modelle - Teil 2: Mehrdimensionale Modelle Y1 - 2016 SN - 978-3-88721-281-0 CY - Hennef ER - TY - JOUR A1 - Hebel, Christoph T1 - Erfahrungen mit der RIN und aktuelle Weiterentwicklungen JF - Straßenverkehrstechnik: Organ der Forschungsgesellschaft für Straßen- und Verkehrswesen, der Bundesvereinigung der Straßenbau- und Verkehrsingenieure und der Österreichischen Forschungsgesellschaft Straße und Verkehr; Zeitschrift für Verkehrsplanung, Verkehrsmanagement, Verkehrssicherheit, Verkehrstechnik Y1 - 2017 SN - 0039-2219 N1 - gedruckt in der Bereichsbibliothek Bayernallee vorhanden VL - 61 IS - 7 SP - 443 EP - 448 PB - Kirschbaum-Verlag CY - Bonn ER - TY - JOUR A1 - Höttges, Jörg T1 - QKan - Management of drainage system data with QGIS JF - Free and Open Source Software for Geospatial (FOSS4G) Conference Proceedings Y1 - 2017 VL - 17 IS - Article 13 SP - 95 EP - 100 ER - TY - THES A1 - Mainz, Stefan T1 - Zur Berechnung der Tragfähigkeit von dünnwandigen Koppelpfetten aus Kaltprofilen für Biegung um die schwache Achse und Torsion Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:gbv:1373-opus-3798 CY - Hamburg ER - TY - BOOK A1 - Uibel, Thomas A1 - Peterson, Leif Arne ED - Uibel, Thomas ED - Peterson, Leif Arne T1 - Tagungsband Aachener Holzbautagung 2017 Y1 - 2017 SN - 2197-4489 PB - FH Aachen CY - Aachen ER - TY - BOOK A1 - Uibel, Thomas A1 - Peterson, Leif Arne ED - Uibel, Thomas ED - Peterson, Leif Arne T1 - Tagungsband Aachener Holzbautagung 2015 Y1 - 2015 SN - 2197-4489 PB - FH Aachen CY - Aachen ER - TY - JOUR A1 - Laumann, Jörg A1 - Mainz, Stefan A1 - Krahwinkel, Manuel T1 - Traglastuntersuchungen an Koppelpfetten bei Biegung um die schwache Achse und Torsion JF - Stahlbau Y1 - 2017 U6 - http://dx.doi.org/10.1002/stab.201710544 SN - 0038-9145 VL - 86 IS - 11 SP - 1005 EP - 1016 PB - Wiley CY - Weinheim ER - TY - JOUR A1 - Valero, Daniel A1 - Bung, Daniel B. T1 - Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment JF - International Journal of Multiphase Flow N2 - A new formulation for the prediction of free surface dynamics related to the turbulence occurring nearby is proposed. This formulation, altogether with a breakup criterion, can be used to compute the inception of self-aeration in high velocity flows like those occurring in hydraulic structures. Assuming a simple perturbation geometry, a kinematic and a non-linear momentum-based dynamic equation are formulated and forces acting on a control volume are approximated. Limiting steepness is proposed as an adequate breakup criterion. Role of the velocity fluctuations normal to the free surface is shown to be the main turbulence quantity related to self-aeration and the role of the scales contained in the turbulence spectrum are depicted. Surface tension force is integrated accounting for large displacements by using differential geometry for the curvature estimation. Gravity and pressure effects are also contemplated in the proposed formulation. The obtained equations can be numerically integrated for each wavelength, hence resulting in different growth rates and allowing computation of the free surface roughness wavelength distribution. Application to a prototype scale spillway (at the Aviemore dam) revealed that most unstable wavelength was close to the Taylor lengthscale. Amplitude distributions have been also obtained observing different scaling for perturbations stabilized by gravity or surface tension. The proposed theoretical framework represents a new conceptualization of self-aeration which explains the characteristic rough surface at the non-aerated region as well as other previous experimental observations which remained unresolved for several decades. Y1 - 2018 U6 - http://dx.doi.org/10.1016/j.ijmultiphaseflow.2017.12.011 SN - 0301-9322 VL - 100 SP - 127 EP - 142 PB - Elsevier CY - Amsterdam ER -