@article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel B.}, title = {Reformulating self-aeration in hydraulic structures: Turbulent growth of free surface perturbations leading to air entrainment}, series = {International Journal of Multiphase Flow}, volume = {100}, journal = {International Journal of Multiphase Flow}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0301-9322}, doi = {10.1016/j.ijmultiphaseflow.2017.12.011}, pages = {127 -- 142}, year = {2018}, abstract = {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.}, language = {en} } @article{ValeroBung2017, author = {Valero, Daniel and Bung, Daniel B.}, title = {Artificial Neural Networks and pattern recognition for air-water flow velocity estimation using a single-tip optical fibre probe}, series = {Journal of Hydro-environment Research}, volume = {19}, journal = {Journal of Hydro-environment Research}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1570-6443}, doi = {10.1016/j.jher.2017.08.004}, pages = {150 -- 159}, year = {2017}, language = {en} } @article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel B.}, title = {Vectrino profiler spatial filtering for shear flows based on the mean velocity gradient equation}, series = {Journal of Hydraulic Engineering}, volume = {144}, journal = {Journal of Hydraulic Engineering}, number = {7}, publisher = {ASCE}, address = {Reston, Va.}, issn = {0733-9429}, doi = {10.1061/(ASCE)HY.1943-7900.0001485}, year = {2018}, abstract = {A new methodology is proposed to spatially filter acoustic Doppler velocimetry data from a Vectrino profiler based on the differential mean velocity equation. Lower and upper bounds are formulated in terms of physically based flow constraints. Practical implementation is discussed, and its application is tested against data gathered from an open-channel flow over a stepped macroroughness surface. The method has proven to detect outliers occurring all over the distance range sampled by the Vectrino profiler and has shown to remain applicable out of the region of validity of the velocity gradient equation. Finally, a statistical analysis suggests that physically obtained bounds are asymptotically representative.}, language = {en} } @article{ValeroBungCrookston2019, author = {Valero, D. and Bung, Daniel B. and Crookston, B. M.}, title = {Closure to "Energy Dissipation of a Type III Basin under Design and Adverse Conditions for Stepped and Smooth Spillways"}, series = {Journal of Hydraulic Engineering}, volume = {146}, journal = {Journal of Hydraulic Engineering}, number = {2}, publisher = {ASCE}, address = {Reston, Va.}, doi = {10.1061/(ASCE)HY.1943-7900.0001669}, year = {2019}, language = {en} } @inproceedings{UibelBlass2013, author = {Uibel, Thomas and Blaß, Hans-Joachim}, title = {Joints with Dowel Type Fasteners in CLT structures}, series = {Focus solid timber solutions : European Conference on Cross Laminated Timber (CLT); May 21-22, 2013, Graz University of Technology, Austria}, booktitle = {Focus solid timber solutions : European Conference on Cross Laminated Timber (CLT); May 21-22, 2013, Graz University of Technology, Austria}, organization = {European Conference on Cross Laminated Timber <2013, Graz>}, isbn = {978-1-85790-181-8 ; 1-85790-181-9}, pages = {119 -- 134}, year = {2013}, language = {en} } @inproceedings{UibelBlass2006, author = {Uibel, Thomas and Blaß, Hans Joachim}, title = {Load Carrying Capacity of Joints with Dowel Type Fasteners in Solid Wood Panels}, series = {Proceedings. CIB-W18 Meeting 2006, Florence, Italy 2006}, booktitle = {Proceedings. CIB-W18 Meeting 2006, Florence, Italy 2006}, issn = {0945-6996}, pages = {1 -- 10}, year = {2006}, language = {en} } @inproceedings{UibelBlass2007, author = {Uibel, Thomas and Blaß, Hans Joachim}, title = {Edge Joints with Dowel Type Fasteners in Cross Laminated Timber}, series = {Proceedings. CIB-W18 Meeting 2007, Bled, Slovenia 2007}, booktitle = {Proceedings. CIB-W18 Meeting 2007, Bled, Slovenia 2007}, issn = {0945-6996}, pages = {1 -- 11}, year = {2007}, language = {en} } @inproceedings{UibelBlass2010, author = {Uibel, Thomas and Blaß, Hans Joachim}, title = {A new method to determine suitable spacings and distances for self-tapping screws}, series = {Meeting ... / International Council for Research and Innovation in Building and Construction, Working Commission W18 - Timber Structures}, volume = {43}, booktitle = {Meeting ... / International Council for Research and Innovation in Building and Construction, Working Commission W18 - Timber Structures}, publisher = {Lehrstuhl f{\"u}r Ingenieurholzbau und Baukonstruktionen}, address = {Karlsruhe}, issn = {1864-1784}, year = {2010}, abstract = {The determination of spacing, edge and end distance requirements for self-tapping screws requires numerous and comprehensive insertion tests. Yet the results of such tests cannot be transferred to other types of screws or even to screws of different diameter because of differences in shape or geometry. To reduce the effort of insertion tests a new method was developed which allows the estimation of required spacings, distances and timber thickness.}, language = {en} } @inproceedings{TullisCrookstonBung2019, author = {Tullis, Blake P. and Crookston, Brian M. and Bung, Daniel B.}, title = {Weir head-discharge relationships: A multi-lab exercise}, series = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, booktitle = {E-proceedings of the 38th IAHR World Congress September 1-6, 2019, Panama City, Panama}, pages = {1 -- 15}, year = {2019}, language = {en} } @inproceedings{StepkesZimmermannMuelleretal.2007, author = {Stepkes, Hermann and Zimmermann, J. and M{\"u}ller, Karsten and Siekmann, Marko and Pinnekamp, Josef}, title = {Economical rehabilitation of sewer systems by ground penetration radar investigations}, series = {Strategic asset management of water supply and wastewater infrastructures : invited papers from the 2nd IWA Leading Edge Conference on Strategic Asset Management (LESAM), Lisbon, October [17 - 19] 2007 / ed. by Helene Alegre and Maria do C{\´e}u Almeida}, booktitle = {Strategic asset management of water supply and wastewater infrastructures : invited papers from the 2nd IWA Leading Edge Conference on Strategic Asset Management (LESAM), Lisbon, October [17 - 19] 2007 / ed. by Helene Alegre and Maria do C{\´e}u Almeida}, publisher = {IWA Publ.}, address = {London}, isbn = {9781843391869}, pages = {501 -- 520}, year = {2007}, language = {en} }