TY - RPRT A1 - Arndt, Detlef A1 - Borchardt, Kerstin A1 - Croy, F. A1 - Geyer, Emil A1 - Henschen, Joachim A1 - Maierhofer, Christiane A1 - Niedack, Marianne A1 - Rudolphi, Michael A1 - Schaurich, Dieter A1 - Weise, Frank A1 - Wiggenhauser, Herbert T1 - Anwendung u. Kombination zerstörungsfreier Prüfverfahren zur Bestimmung der Mauerwerksfeuchte im Deutschen Dom N2 - Am Deutschen Dom wurden Mikrowellenabsorptionsmessungen, Radar und Infarot- Thermographie als moderne zerstörungsfreie Prüfverfahren der Feuchtemessung in Mauerwerk erprobt. Ergänzende numerische Simulationsrechnungen des gekoppelten Wärme- und Feuchtetransports sollen bei der Auswahl von Trockenlegungskonzepten helfen. T3 - BAM Forschungsberichtreihe - 200 PY - 1994 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2509 SN - 978-3-89429-423-X SN - 0938-5533 VL - 200 SP - 1 EP - 84 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-250 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weise, Frank A1 - Arndt, Detlef ED - Venzmer, H. T1 - Anwendungsmöglichkeiten der aktiven Infrarot-Thermografie im Bauwesen T2 - 11. Hanseatische Sanierungstage CY - Kühlungsborn, Deutschland DA - 2000-11-09 PY - 2000 SN - 3-345-00726-6 N1 - Serientitel: Schriftenreihe / Feuchte- und Altbausanierung e.V. – Series title: Schriftenreihe / Feuchte- und Altbausanierung e.V. IS - 11 PB - Verl. Bauwesen CY - Berlin AN - OPUS4-3348 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Drame, Christian A1 - Lohrer, Christian A1 - Arndt, Detlef A1 - Grätz, Rainer A1 - Förster, H. ED - Stolz, T. T1 - Untersuchung von Deflagrationen in geschlossenen Rohrleitungen T2 - 228. PTB-Seminar CY - Braunschweig, Deutschland DA - 2007-06-26 KW - Deflagration KW - Geschlossene Rohrleitung KW - Propan PY - 2007 SN - 978-3-86509-700-2 SP - 27 EP - 33 PB - Wirtschaftsverlag N. W. Verlag für neue Wissenschaft CY - Bremerhaven AN - OPUS4-14996 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lohrer, Christian A1 - Hahn, Matthias A1 - Arndt, Detlef A1 - Grätz, Rainer T1 - Einfluss eines 90°-Rohrbogens in einer technischen Rohrleitung auf reaktive Strömungen N2 - Bereits einfache Rohreinbauten wie 90°-Rohrbögen erhöhen den Turbulenzgrad einer Strömung signifikant. Bei Explosionsversuchen von Propan/Luft-Gemischen in einer DN150-Rohrleitung mit einem 90°-Rohrbogen wurden sowohl stark beschleunigte Deflagrationen als auch Detonationen mit maximalen Explosionsdrücken von über 65 bar (abs.) beobachtet. KW - CTA (constant temperature anemometry) KW - Deflagration KW - Detonation KW - Explosion KW - Rohrbogen PY - 2008 DO - https://doi.org/10.1002/cite.200700174 SN - 0009-286X SN - 1522-2640 VL - 80 IS - 5 SP - 649 EP - 657 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-17450 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Lohrer, Christian A1 - Drame, Christian A1 - Arndt, Detlef A1 - Grätz, Rainer A1 - Schönbucher, A. T1 - Explosion processes and DDT of various flammable gas/air mixtures in long closed pipes containing obstacles T2 - Hazards XX - "Process Safety and Environmental Protection" CY - Manchester, UK DA - 2008-04-15 KW - Deflagration KW - Detonation KW - DDT KW - MESG KW - Obstacles PY - 2008 SN - 978-0-85295-523-9 IS - Symposium Series No. 154 SP - 247 EP - 261 AN - OPUS4-17451 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Poli, Marco A1 - Scheider, Swen A1 - Arndt, Detlef A1 - Grätz, Rainer A1 - Schröder, Volkmar T1 - Auswirkungen von Turbulenzen auf die Druckentlastung von Gasexplosionen N2 - Zur Bemessung von Druckentlastungseinrichtungen bei Gasexplosionen in Umschließungen existieren derzeitig nur wenige wissenschaftlich fundierte Auslegungskriterien, die die konstruktiven Randbedingungen oder Prozessbedingungen der explosionsgefährdeten Anlagenteile ausreichend berücksichtigen. Aus diesem Grund werden in der Praxis häufig stark konservative Annahmen getroffen, die zu erheblichen Überdimensionierungen der Druckentlastungseinrichtungen führen können. Aus sicherheitstechnischer Perspektive können gerade diese vermeintlichen Sicherheitsmargen zu einer erheblichen Beschleunigung des transienten Druckverlaufs und damit eher zu einer Unterdimensionierung führen oder sogar den Übergang von Deflagrationen zu Detonationen begünstigen. Sowohl Messungen als auch erste Simulationen mit Hilfe von CFD-Modellen begründen die Notwendigkeit weiterer Untersuchungen mit explosionsgefährdeten Gasanlagen. Da insbesondere bei turbulenten Verbrennungsvorgängen in den Normen Verbesserungspotential herrscht, wird bei der BAM zukünftig verstärkt dieses Thema in Forschungsarbeiten berücksichtigt. KW - Explosionsschutz KW - Druckentlastung KW - Turbulenz PY - 2011 SN - 0030-834X VL - 121 IS - 1 SP - 51 EP - 54 PB - Wirtschaftsverl. NW CY - Bremerhaven AN - OPUS4-23521 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blanchard, Robert A1 - Arndt, Detlef A1 - Grätz, Rainer A1 - Poli, Marco A1 - Scheider, Swen T1 - Explosions in closed pipes containing baffles and 90 degree bends N2 - There is a general lack of information on the effects of full-bore obstacles on combustion in the literature, these obstacles are prevalent in many applications and knowledge of their effects on phenomena including burning rate, flame acceleration and DDT is important for the correct placing of explosion safety devices such as flame arresters and venting devices. In this work methane, propane, ethylene and hydrogen-air explosions were investigated in an 18 m long DN150 closed pipe with a 90 degree bend and various baffle obstacles placed at a short distance from the ignition source. After carrying out multiple experiments with the same configuration it was found that a relatively large variance existed in the measured flame speeds and overpressures, this was attributed to a stochastic element in how flames evolved and also how they caused and interacted with turbulence to produce flame acceleration. This led to several experiments being carried out for one configuration in order to obtain a meaningful average. It was shown that a 90 degree bend in a long tube had the ability to enhance flame speeds and overpressures, and shorten the run-up distance to DDT to a varying degree for a number of gases. In terms of the qualitative effects on these parameters they were comparable to baffle type obstacles with a blockage ratios of between 10 and 20%. KW - Baffle KW - Bend KW - Deflagration to detonation transition KW - Explosion enhancement PY - 2010 DO - https://doi.org/10.1016/j.jlp.2009.09.004 SN - 0950-4230 SN - 1873-3352 VL - 23 SP - 253 EP - 259 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-20843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Blanchard, Robert A1 - Arndt, Detlef A1 - Grätz, Rainer A1 - Scheider, Swen T1 - Effect of ignition position on the run-up distance to DDT for hydrogen-air explosions N2 - The method described in this paper enabled reliable and accurate positioning of an overdriven detonation by calculation of shock wave velocities (detonation and retonation) for hydrogen explosions in a closed 18 m long horizontal DN150 pipe. This enabled an empirical correlation between the ignition position and the run-up distance to DDT to be determined. It was shown that the initial ability of the flame to expand unobstructed and the piston-like effect of burnt gas expanding against the closed end of the tube contributed to initial flame acceleration and hence were able to affect the run-up distance to overdriven detonation. Flame speeds and rates of initial pressure rise were also used to explain how these two competing effects were able to produce a minimum in the run-up distance to DDT. The shortest run-up distance to DDT, relative to the ignition position, for this pipe and gas configuration was found when the ignition position was placed 5.6 pipe diameters (or 0.9 m) from the closed pipe end. The shortest run-up distance to DDT relative to the end of the pipe was recorded when the ignition source was placed 4.4 pipe diameters or 0.7 m from the pipe end. KW - Deflagration to detonation transition (DDT) KW - Ignition position KW - Hydrogen KW - Detonation and retonation PY - 2011 DO - https://doi.org/10.1016/j.jlp.2010.12.007 SN - 0950-4230 SN - 1873-3352 VL - 24 SP - 194 EP - 199 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-23149 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Poli, Marco A1 - Arndt, Detlef A1 - Scheider, Swen A1 - Grätz, Rainer T1 - Grenzen bei der Auslegung von turbulenten Explosionsdruckentlastungen T2 - 12. Kolloquium zu Fragen der chemischen und physikalischen Sicherheitstechnik CY - Berlin, Deutschland DA - 2010-06-15 KW - Explosionsdruckentlastung KW - Turbulente Verbrennung KW - Explosionsschutz PY - 2010 SN - 978-3-9813550-1-7 SN - 0938-5533 SP - 19 EP - 22 PB - BAM Bundesanstalt für Materialforschung und -prüfung CY - Berlin AN - OPUS4-21497 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hussels, Maria-Teresa A1 - Chruscicki, Sebastian A1 - Arndt, Detlef A1 - Scheider, Swen A1 - Prager, Jens A1 - Homann, Tobias A1 - Habib, Abdel Karim T1 - Localization of transient events threatening pipeline integrity by fiber-optic distributed acoustic sensing N2 - Pipe integrity is a central concern regarding technical safety, availability, and environmental compliance of industrial plants and pipelines. A condition monitoring system that detects and localizes threats in pipes prior to occurrence of actual structural failure, e.g., leakages, especially needs to target transient events such as impacts on the pipe wall or pressure waves travelling through the medium. In the present work, it is shown that fiber-optic distributed acoustic sensing (DAS) in conjunction with a suitable application geometry of the optical fiber sensor allows to track propagating acoustic waves in the pipeline wall on a fast time-scale. Therefore, short impacts on the pipe may be localized with high fidelity. Moreover, different acoustic modes are identified, and their respective group velocities are in good agreement with theoretical predications. In another set of experiments modeling realistic damage scenarios, we demonstrate that pressure waves following explosions of different gas mixtures in pipes can be observed. Velocities are verified by local piezoelectric pressure transducers. Due to the fully distributed nature of the fiber-optic sensing system, it is possible to record accelerated motions in detail. Therefore, in addition to detection and localization of threatening events for infrastructure monitoring, DAS may provide a powerful tool to study the development of gas explosions in pipes, e.g., investigation of deflagration-to-detonation-transitions (DDT). KW - Distributed acoustic sensing (DAS) KW - Distributed vibrations sensing (DVS) KW - Fiber-optic sensing KW - Condition monitoring KW - Pipeline integrity KW - Gas explosion PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488555 DO - https://doi.org/10.3390/s19153322 SN - 1424-8220 VL - 19 IS - 15 SP - 3322, 1 EP - 20 PB - MDPI CY - Basel, CH AN - OPUS4-48855 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -