TY - CHAP A1 - Oertel, Mario A1 - Bung, Daniel Bernhard T1 - Numerische Strömungssimulation von Fließgewässern - Wo stehen wir und was werden wir im Laufe der nächsten Jahre erreichen? T2 - Simulationsverfahren und Modelle für Wasserbau und Wasserwirtschaft = Simulation techniques and models for hydraulic engineering and water management / 37. Dresdner Wasserbaukolloquium 2014, 13. - 14. März 2014. (Dresdner wasserbauliche Mitteilungen ; H. 50) Y1 - 2014 SN - 978-3-86780-349-6 SP - 19 EP - 30 ER - TY - CHAP A1 - Oertel, Mario A1 - Balmes, Jan P. A1 - Bung, Daniel Bernhard T1 - Numerical simulation of erosion processes on crossbar block ramps T2 - E-proceedings of the 36th IAHR World Congress 28 June – 3 July, 2015, The Hague, the Netherlands Y1 - 2015 SP - 1 EP - 8 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Valero, Daniel T1 - Image processing for bubble image velocimetry in self-aerated flows T2 - E-proceedings of the 36th IAHR World Congress 28 June – 3 July, 2015, The Hague, the Netherlands Y1 - 2015 SP - 1 EP - 8 ER - TY - CHAP A1 - Bung, Daniel Bernhard T1 - Observations on non-aerated flow and air entrainment on moderately sloped stepped spillways T2 - 7th Chinese-German Joint Symposium on Hydraulic and Ocean Engineering : 8. - 12. Sept. 2014, Hannover Y1 - 2014 N1 - Kennwortgeschützter Zugang. Passwort bei Prof. Bung, Fachbereich Bauingenieurwesen SP - 1 EP - 8 ER - TY - CHAP A1 - Bung, Daniel Bernhard A1 - Oertel, Mario T1 - Manipulation of non-aerated cavity flow on a stepped spillway model T2 - 3rd European IAHR Congress : April 14 – 16, 2014, Porto Y1 - 2014 PB - Univ. of Porto CY - Porto ER - TY - CHAP A1 - Mohan, Nijanthan A1 - Groß, Rolf Fritz A1 - Menzel, Karsten A1 - Theis, Fabian T1 - Opportunities and Challenges in the Implementation of Building Information Modeling for Prefabrication of Heating, Ventilation and Air Conditioning Systems in Small and Medium-Sized Contracting Companies in Germany – A Case Study T2 - WIT Transactions on The Built Environment, Vol. 205 N2 - Even though BIM (Building Information Modelling) is successfully implemented in most of the world, it is still in the early stages in Germany, since the stakeholders are sceptical of its reliability and efficiency. The purpose of this paper is to analyse the opportunities and obstacles to implementing BIM for prefabrication. Among all other advantages of BIM, prefabrication is chosen for this paper because it plays a vital role in creating an impact on the time and cost factors of a construction project. The project stakeholders and participants can explicitly observe the positive impact of prefabrication, which enables the breakthrough of the scepticism factor among the small-scale construction companies. The analysis consists of the development of a process workflow for implementing prefabrication in building construction followed by a practical approach, which was executed with two case studies. It was planned in such a way that, the first case study gives a first-hand experience for the workers at the site on the BIM model so that they can make much use of the created BIM model, which is a better representation compared to the traditional 2D plan. The main aim of the first case study is to create a belief in the implementation of BIM Models, which was succeeded by the execution of offshore prefabrication in the second case study. Based on the case studies, the time analysis was made and it is inferred that the implementation of BIM for prefabrication can reduce construction time, ensures minimal wastes, better accuracy, less problem-solving at the construction site. It was observed that this process requires more planning time, better communication between different disciplines, which was the major obstacle for successful implementation. This paper was carried out from the perspective of small and medium-sized mechanical contracting companies for the private building sector in Germany. KW - building information modelling KW - HVAC KW - prefabrication KW - construction KW - small and medium scaled companies Y1 - 2021 U6 - https://doi.org/10.2495/BIM210101 SN - 1743-3509 N1 - 4th International Conference on Building Information Modelling (BIM) in Design, Construction and Operations, 1–3 September 2021. Santiago de Compostela, Spain SP - 117 EP - 126 PB - WIT Press CY - Southampton ER - TY - CHAP A1 - Langohr, Philipp A1 - Bung, Daniel Bernhard A1 - Crookston, Brian M. ED - Ortega-Sánchez, Miguel T1 - Hybrid investigation of labyrinth weirs: Discharge capacity and energy dissipation T2 - Proceedings of the 39th IAHR World Congress N2 - The replacement of existing spillway crests or gates with labyrinth weirs is a proven techno-economical means to increase the discharge capacity when rehabilitating existing structures. However, additional information is needed regarding energy dissipation of such weirs, since due to the folded weir crest, a three-dimensional flow field is generated, yielding more complex overflow and energy dissipation processes. In this study, CFD simulations of labyrinth weirs were conducted 1) to analyze the discharge coefficients for different discharges to compare the Cd values to literature data and 2) to analyze and improve energy dissipation downstream of the structure. All tests were performed for a structure at laboratory scale with a height of approx. P = 30.5 cm, a ratio of the total crest length to the total width of 4.7, a sidewall angle of 10° and a quarter-round weir crest shape. Tested headwater ratios were 0.089 ≤ HT/P ≤ 0.817. For numerical simulations, FLOW-3D Hydro was employed, solving the RANS equations with use of finite-volume method and RNG k-ε turbulence closure. In terms of discharge capacity, results were compared to data from physical model tests performed at the Utah Water Research Laboratory (Utah State University), emphasizing higher discharge coefficients from CFD than from the physical model. For upstream heads, some discrepancy in the range of ± 1 cm between literature, CFD and physical model tests was identified with a discussion regarding differences included in the manuscript. For downstream energy dissipation, variable tailwater depths were considered to analyze the formation and sweep-out of a hydraulic jump. It was found that even for high discharges, relatively low downstream Froude numbers were obtained due to high energy dissipation involved by the three-dimensional flow between the sidewalls. The effects of some additional energy dissipation devices, e.g. baffle blocks or end sills, were also analyzed. End sills were found to be non-effective. However, baffle blocks with different locations may improve energy dissipation downstream of labyrinth weirs. Y1 - 2022 SN - 978-90-832612-1-8 U6 - https://doi.org/10.3850/IAHR-39WC252171192022738 SN - 2521-7119 (print) SN - 2521-716X (online) N1 - 39th IAHR World Congress, 19. - 24. Juni 2022, Granada SP - 2313 EP - 2318 PB - International Association for Hydro-Environment Engineering and Research (IAHR) CY - Madrid ER - TY - CHAP A1 - Crookston, Brian M. A1 - Bung, Daniel Bernhard ED - Ortega-Sánchez, Miguel T1 - Application of RGB-D cameras in hydraulic laboratory studies T2 - Proceedings of the 39th IAHR World Congress N2 - Non-intrusive measuring techniques have attained a lot of interest in relation to both hydraulic modeling and prototype applications. Complimenting acoustic techniques, significant progress has been made for the development of new optical methods. Computer vision techniques can help to extract new information, e. g. high-resolution velocity and depth data, from videos captured with relatively inexpensive, consumer-grade cameras. Depth cameras are sensors providing information on the distance between the camera and observed features. Currently, sensors with different working principles are available. Stereoscopic systems reference physical image features (passive system) from two perspectives; in order to enhance the number of features and improve the results, a sensor may also estimate the disparity from a detected light to its original projection (active stereo system). In the current study, the RGB-D camera Intel RealSense D435, working on such stereo vision principle, is used in different, typical hydraulic modeling applications. All tests have been conducted at the Utah Water Research Laboratory. This paper will demonstrate the performance and limitations of the RGB-D sensor, installed as a single camera and as camera arrays, applied to 1) detect the free surface for highly turbulent, aerated hydraulic jumps, for free-falling jets and for an energy dissipation basin downstream of a labyrinth weir and 2) to monitor local scours upstream and downstream of a Piano Key Weir. It is intended to share the authors’ experiences with respect to camera settings, calibration, lightning conditions and other requirements in order to promote this useful, easily accessible device. Results will be compared to data from classical instrumentation and the literature. It will be shown that even in difficult application, e. g. the detection of a highly turbulent, fluctuating free-surface, the RGB-D sensor may yield similar accuracy as classical, intrusive probes. Y1 - 2022 SN - 978-90-832612-1-8 U6 - https://doi.org/10.3850/IAHR-39WC252171192022964 SN - 2521-7119 (print) SN - 2521-716X (online) N1 - 39th IAHR World Congress, 19. - 24. Juni 2022, Granada SP - 5127 EP - 5133 PB - International Association for Hydro-Environment Engineering and Research (IAHR) CY - Madrid ER - TY - CHAP A1 - Uibel, Thomas A1 - Blaß, Hans Joachim T1 - A new method to determine suitable spacings and distances for self-tapping screws T2 - Meeting ... / International Council for Research and Innovation in Building and Construction, Working Commission W18 - Timber Structures N2 - 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. Y1 - 2010 SN - 1864-1784 N1 - Paper 43-21-2 VL - 43 PB - Lehrstuhl für Ingenieurholzbau und Baukonstruktionen CY - Karlsruhe ER -