@article{ValeroSchalkoFriedrichetal.2021, author = {Valero, Daniel and Schalko, Isabella and Friedrich, Heide and Abad, Jorge D. and Bung, Daniel Bernhard and Donchyts, Gennadii and Felder, Stefan and Ferreira, Rui M. L. and Hohermuth, Benjamin and Kramer, Matthias and Li, Danxun and Mendes, Luis and Moreno-Rodenas, Antonio and Nones, Michael and Paron, Paolo and Ruiz-Villanueva, Virginia and Wang, Ruo-Qian and Franca, Mario J.}, title = {Pathways towards democratization of hydro-environment observations and data}, series = {Iahr White Paper Series}, journal = {Iahr White Paper Series}, number = {1}, publisher = {International Association for Hydro-Environment Engineering and Research (IAHR)}, pages = {1 -- 9}, year = {2021}, language = {en} } @article{BungErpicumTullis2020, author = {Bung, Daniel Bernhard and Erpicum, S{\´e}bastien and Tullis, Blanke P.}, title = {Advances in hydraulic structures engineering}, series = {Journal of Hydraulic Engineering}, volume = {147}, journal = {Journal of Hydraulic Engineering}, number = {1}, publisher = {ASCE}, address = {Reston, Va.}, issn = {0733-9429 (Druckausgabe)}, doi = {10.1061/(ASCE)HY.1943-7900.0001851}, pages = {1 Seite}, year = {2020}, language = {en} } @article{RichterWichernGroempingetal.2020, author = {Richter, L. and Wichern, M. and Gr{\"o}mping, Markus and Robecke, U. and Haberkamp, J.}, title = {Ammonium recovery from process water of digested sludge dewatering by membrane contactors}, series = {Water Practice and Technology}, volume = {15}, journal = {Water Practice and Technology}, number = {1}, publisher = {IWA Publishing}, address = {London}, issn = {1751-231X}, doi = {10.2166/wpt.2020.002}, pages = {84 -- 91}, year = {2020}, abstract = {Membrane contactors are a promising alternative for nitrogen removal and recovery from process water compared to other physicochemical and biological sidestream treatment processes. M{\"u}nster wastewater treatment plant (WWTP) is the first municipal WWTP in Germany operating a full-scale membrane contactor system to improve the nitrogen elimination and recovery efficiency. Factors influencing the operation and membrane performance are investigated in an accompanying research project. Additional operational aspects of the applied membrane modules are investigated in detail using a bench-scale membrane contactor. First results of the full-scale application demonstrate a high nitrogen removal efficiency of >95\%.}, language = {de} } @article{KerresGredigkHoffmannJatheetal.2020, author = {Kerres, Karsten and Gredigk-Hoffmann, Sylvia and Jathe, R{\"u}diger and Orlik, Stefan and Sariyildiz, Mustafa and Schmidt, Torsten and Sympher, Klaus-Jochen and Uhlenbroch, Adrian}, title = {Future approaches for sewer system condition assessment}, series = {Water Practice \& Technology}, journal = {Water Practice \& Technology}, number = {15 (2)}, publisher = {IWA Publishing}, address = {London}, issn = {1751-231X}, doi = {10.2166/wpt.2020.027}, pages = {386 -- 393}, year = {2020}, abstract = {Different analytical approaches exist to describe the structural substance or wear reserve of sewer systems. The aim is to convert engineering assessments of often complex defect patterns into computational algorithms and determine a substance class for a sewer section or manhole. This analytically determined information is essential for strategic rehabilitation planning processes up to network level, as it corresponds to the most appropriate rehabilitation type and can thus provide decision-making support. Current calculation methods differ clearly from each other in parts, so that substance classes determined by the different approaches are only partially comparable with each other. The objective of the German R\&D cooperation project 'SubKanS' is to develop a methodology for classifying the specific defect patterns resulting from the interaction of all the individual defects, and their severities and locations. The methodology takes into account the structural substance of sewer sections and manholes, based on real data and theoretical considerations analogous to the condition classification of individual defects. The result is a catalogue of defect patterns and characteristics, as well as associated structural substance classifications of sewer systems (substance classes). The methodology for sewer system substance classification is developed so that the classification of individual defects can be transferred into a substance class of the sewer section or manhole, eventually taking into account further information (e.g. pipe material, nominal diameter, etc.). The result is a validated methodology for automated sewer system substance classification.}, language = {en} } @article{KuhnhenneRegerPyschnyetal.2020, author = {Kuhnhenne, Markus and Reger, Vitali and Pyschny, Dominik and D{\"o}ring, Bernd}, title = {Influence of airtightness of steel sandwich panel joints on heat losses}, series = {E3S Web of Conferences 12th Nordic Symposium on Building Physics (NSB 2020)}, volume = {172}, journal = {E3S Web of Conferences 12th Nordic Symposium on Building Physics (NSB 2020)}, number = {Art. 05008}, publisher = {EDP Sciences}, address = {Les Ulis}, doi = {10.1051/e3sconf/202017205008}, pages = {6}, year = {2020}, abstract = {Energy saving ordinances requires that buildings must be designed in such a way that the heat transfer surface including the joints is permanently air impermeable. The prefabricated roof and wall panels in lightweight steel constructions are airtight in the area of the steel covering layers. The sealing of the panel joints contributes to fulfil the comprehensive requirements for an airtight building envelope. To improve the airtightness of steel sandwich panels, additional sealing tapes can be installed in the panel joint. The influence of these sealing tapes was evaluated by measurements carried out by the RWTH Aachen University - Sustainable Metal Building Envelopes. Different installation situations were evaluated by carrying out airtightness tests for different joint distances. In addition, the influence on the heat transfer coefficient was also evaluated using the Finite Element Method (FEM). The combination of obtained air volume flow and transmission losses enables to create an "effective heat transfer coefficient" due to transmission and infiltration. This summarizes both effects in one value and is particularly helpful for approximate calculations on energy efficiency.}, language = {en} } @article{RegerKuhnhenneEbbertetal.2020, author = {Reger, Vitali and Kuhnhenne, Markus and Ebbert, Thiemo and Hachul, Helmut and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Nutzung erneuerbarer Energien durch thermische Aktivierung von Komponenten aus Stahl}, series = {Stahlbau}, volume = {2020}, journal = {Stahlbau}, number = {Volume 89, Issue 6512-519}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-1049}, doi = {10.1002/stab.202000031}, pages = {512 -- 519}, year = {2020}, abstract = {Die Versorgung von Neubauten soll m{\"o}glichst weitgehend unabh{\"a}ngig von fossilen Energietr{\"a}gern erfolgen. Erneuerbare Energien spielen daf{\"u}r eine gewichtige Rolle. Eine gute M{\"o}glichkeit, erneuerbare Energien ohne viel zus{\"a}tzlichen Aufwand nutzbar zu machen, ist, bereits vorhandenen Komponenten im Geb{\"a}ude zus{\"a}tzliche Funktionen zu geben. Hier kann bspw. die Fassade oder das Dach solarthermisch aktiviert oder durch Fotovoltaikmodule erg{\"a}nzt werden. Auch Tiefgr{\"u}ndungen k{\"o}nnen neben der statischen Funktion noch eine geothermische Funktion zur Aufnahme oder Abgabe von W{\"a}rme erhalten. Neben der Erzeugung bietet sich auch f{\"u}r die Verteilung der W{\"a}rme oder K{\"a}lte im Geb{\"a}ude die Integration in Bauteile an. Hier kann bspw. der Boden durch eine Fußbodenheizung oder die Decke durch Deckenstrahlplatten aktiviert werden. Im Rahmen der Ver{\"o}ffentlichung wird auf die thermische Aktivierung von Stahlkomponenten eingegangen. Es wird eine L{\"o}sung vorgestellt, die vorgeh{\"a}ngte hinterl{\"u}ftete Stahlfassade (VHF) solarthermisch zu aktivieren. Außerdem werden zwei M{\"o}glichkeiten zur geothermischen Aktivierung von Tiefgr{\"u}ndungen mittels Stahlpf{\"a}hlen gezeigt. Zuletzt wird ein System zur thermischen Aktivierung von Stahltrapezprofilen an der Decke erl{\"a}utert, welches W{\"a}rme zuf{\"u}hren oder bei Bedarf abf{\"u}hren kann.}, language = {de} } @article{BungCrookstonValero2020, author = {Bung, Daniel Bernhard and Crookston, Brian M. and Valero, Daniel}, title = {Turbulent free-surface monitoring with an RGB-D sensor: the hydraulic jump case}, series = {Journal of Hydraulic Research}, journal = {Journal of Hydraulic Research}, publisher = {Taylor \& Francis}, address = {London}, issn = {1814-2079}, doi = {10.1080/00221686.2020.1844810}, year = {2020}, language = {en} } @article{ValeroChansonBung2020, author = {Valero, Daniel and Chanson, Hubert and Bung, Daniel Bernhard}, title = {Robust estimators for free surface turbulence characterization: A stepped spillway application}, series = {Flow Measurement and Instrumentation}, volume = {76}, journal = {Flow Measurement and Instrumentation}, number = {Art. 101809}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-5986}, doi = {10.1016/j.flowmeasinst.2020.101809}, year = {2020}, abstract = {Robust estimators are parameters insensitive to the presence of outliers. However, they presume the shape of the variables' probability density function. This study exemplifies the sensitivity of turbulent quantities to the use of classic and robust estimators and the presence of outliers in turbulent flow depth time series. A wide range of turbulence quantities was analysed based upon a stepped spillway case study, using flow depths sampled with Acoustic Displacement Meters as the flow variable of interest. The studied parameters include: the expected free surface level, the expected fluctuation intensity, the depth skewness, the autocorrelation timescales, the vertical velocity fluctuation intensity, the perturbations celerity and the one-dimensional free surface turbulence spectrum. Three levels of filtering were utilised prior to applying classic and robust estimators, showing that comparable robustness can be obtained either using classic estimators together with an intermediate filtering technique or using robust estimators instead, without any filtering technique.}, language = {en} } @article{PetersonOsterPeterson2020, author = {Peterson-Oster, Madeleine and Peterson, Leif Arne}, title = {Gewerbebau: Modellprojekt mit neuem elementiertem, freistehendem Fassadensystem}, series = {Bauen mit Holz, Der Zimmermann}, journal = {Bauen mit Holz, Der Zimmermann}, publisher = {Rudolf M{\"u}ller}, address = {K{\"o}ln}, issn = {0005-6545}, year = {2020}, abstract = {Die im Zuge einer Betriebs{\"u}bergabe anstehende Baumaßnahmen am eigenen B{\"u}ro- und Produktionsgeb{\"a}ude boten ideale Voraussetzung zur Anwendung einer raum­-kreierenden Außenhaut. Mit der elementierten, freistehenden Eichenholz-Fassade wurde ein bis dahin weitgehend funktionales Bauwerk substanzschonend und zugleich optisch ansprechender umgestaltet.}, language = {de} } @article{PetersonOsterPeterson2020, author = {Peterson-Oster, Madeleine and Peterson, Leif Arne}, title = {Fassadensystem: Optisch ansprechend, freistehend, elementiert und aus Eichenholz}, series = {Bauen mit Holz, Der Zimmermann}, journal = {Bauen mit Holz, Der Zimmermann}, publisher = {Rudolf M{\"u}ller}, address = {K{\"o}ln}, issn = {0005-6545}, year = {2020}, abstract = {Bei der Entwicklung des Fassadensystems ging es darum die m{\"o}gliche Dauerhaftigkeit von Holz bei direkter Bewitterung zu maximieren. Gleichzeitig soll gezeigt werden, dass mittels durchdachter Ans{\"a}tze beim konstruktiven Holzschutz und die Wahl einer geeigneten Holzart langlebige Konstruktionen realisiert werden k{\"o}nnen.}, language = {de} } @article{ValeroChansonBung2019, author = {Valero, Daniel and Chanson, Hubert and Bung, Daniel Bernhard}, title = {Robust estimators for turbulence properties assessment}, pages = {1 -- 24}, year = {2019}, language = {en} } @article{KramerValeroChansonetal.2019, author = {Kramer, Matthias and Valero, Daniel and Chanson, Hubert and Bung, Daniel Bernhard}, title = {Towards reliable turbulence estimations with phase-detection probes: an adaptive window cross-correlation technique}, series = {Experiments in Fluids}, volume = {60}, journal = {Experiments in Fluids}, publisher = {Springer}, address = {Berlin}, issn = {1432-1114}, doi = {10.1007/s00348-018-2650-9}, year = {2019}, language = {en} } @article{ValeroVitiGualtieri2019, author = {Valero, Daniel and Viti, Nicolo and Gualtieri, Carlo}, title = {Numerical Simulation of Hydraulic Jumps. Part 1: Experimental Data for Modelling Performance Assessment}, series = {Water}, volume = {11}, journal = {Water}, number = {1}, publisher = {MDPI}, address = {Basel}, issn = {2073-4441}, doi = {10.3390/w11010036}, pages = {Art. Nr. 36}, year = {2019}, language = {en} } @article{VitiValeroGualtieri2019, author = {Viti, Nicolo and Valero, Daniel and Gualtieri, Carlo}, title = {Numerical Simulation of Hydraulic Jumps. Part 2: Recent Results and Future Outlook}, series = {Water}, volume = {11}, journal = {Water}, number = {1}, issn = {2073-4441}, doi = {10.3390/w11010028}, pages = {Art. Nr. 28}, year = {2019}, language = {en} } @article{GronsfeldJoachimMalecha2019, author = {Gronsfeld, Richard and Joachim, Klubert and Malecha, Hartmut}, title = {3-D-Visualisierung von vorhandenen Staubauwerken zur holistischen Planung und {\"U}berwachung}, series = {Wasserwirtschaft}, volume = {109}, journal = {Wasserwirtschaft}, number = {5}, publisher = {Springer}, address = {Berlin}, issn = {2192-8762}, doi = {10.1007/s35147-019-0075-x}, pages = {82 -- 85}, year = {2019}, language = {de} } @article{ValeroBungCrookston2019, author = {Valero, D. and Bung, Daniel Bernhard 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} } @article{RegerKuhnhenneHachuletal.2019, author = {Reger, Vitali and Kuhnhenne, Markus and Hachul, Helmut and D{\"o}ring, Bernd and Blanke, Tobias and G{\"o}ttsche, Joachim}, title = {Plusenergiegeb{\"a}ude 2.0 in Stahlleichtbauweise}, series = {Stahlbau}, volume = {88}, journal = {Stahlbau}, number = {6}, publisher = {Ernst \& Sohn}, address = {Berlin}, issn = {1437-1049 (E-journal), 0038-9145 (print)}, doi = {10.1002/stab.201900034}, pages = {522 -- 528}, year = {2019}, language = {de} } @article{ZhangValeroBungetal.2018, author = {Zhang, G. and Valero, Daniel and Bung, Daniel Bernhard and Chanson, H.}, title = {On the estimation of free-surface turbulence using ultrasonic sensors}, series = {Flow Measurement and Instrumentation}, volume = {60}, journal = {Flow Measurement and Instrumentation}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-5986}, doi = {10.1016/j.flowmeasinst.2018.02.009}, pages = {171 -- 184}, year = {2018}, abstract = {Accurate determination of free-surface dynamics has attracted much research attention during the past decade and has important applications in many environmental and water related areas. In this study, the free-surface dynamics in several turbulent flows commonly found in nature were investigated using a synchronised setup consisting of an ultrasonic sensor and a high-speed video camera. Basic sensor capabilities were examined in dry conditions to allow for a better characterisation of the present sensor model. The ultrasonic sensor was found to adequately reproduce free-surface dynamics up to the second order, especially in two-dimensional scenarios with the most energetic modes in the low frequency range. The sensor frequency response was satisfactory in the sub-20 Hz band, and its signal quality may be further improved by low-pass filtering prior to digitisation. The application of the USS to characterise entrapped air in high-velocity flows is also discussed.}, language = {en} } @article{ValeroBung2018, author = {Valero, Daniel and Bung, Daniel Bernhard}, 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{BungValero2018, author = {Bung, Daniel Bernhard and Valero, Daniel}, title = {Re-aeration on stepped spillways with special consideration of entrained and entrapped air}, series = {Geosciences}, volume = {8}, journal = {Geosciences}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2076-3263}, pages = {Article number 333}, year = {2018}, abstract = {As with most high-velocity free-surface flows, stepped spillway flows become self-aerated when the drop height exceeds a critical value. Due to the step-induced macro-roughness, the flow field becomes more turbulent than on a similar smooth-invert chute. For this reason, cascades are oftentimes used as re-aeration structures in wastewater treatment. However, for stepped spillways as flood release structures downstream of deoxygenated reservoirs, gas transfer is also of crucial significance to meet ecological requirements. Prediction of mass transfer velocities becomes challenging, as the flow regime differs from typical previously studied flow conditions. In this paper, detailed air-water flow measurements are conducted on stepped spillway models with different geometry, with the aim to estimate the specific air-water interface. Re-aeration performances are determined by applying the absorption method. In contrast to earlier studies, the aerated water body is considered a continuous mixture up to a level where 75\% air concentration is reached. Above this level, a homogenous surface wave field is considered, which is found to significantly affect the total air-water interface available for mass transfer. Geometrical characteristics of these surface waves are obtained from high-speed camera investigations. The results show that both the mean air concentration and the mean flow velocity have influence on the mass transfer. Finally, an empirical relationship for the mass transfer on stepped spillway models is proposed.}, language = {en} }