TY - CONF A1 - Otremba, Frank A1 - Romero-Navarrete, José A. T1 - Modelling a partly filled road tanker during an emergency braking N2 - Figure 10 illustrates the theoretical results from the simplified model considered, together with the experimental data. These results and measurements are presented one next to the other, in order to facilitate the validity analysis of the proposed simulation methodology. These results illustrate that the trends are comparable for both sets of data, that is, a similar range is obtained for all of the variables reported. A lower pressure is generated in chamber 5, which is attributed to the shorter length of this chamber. However, such increase in pressure does not correspond exactly to the difference of lengths, as the ratio of lengths would cause a differential pressure of 2.3/1.23 = 1.86, while the ratio of average pressures is on the order of 2. That is, there is an incremental, which is associated to the maximum height attained by the fluid in the chamber. The major difference between both sets of data, the experimental and theoretical, is that the theoretical do not include much of the noise and random oscillations reported in the experimental data. Such noise, however, is of very low amplitude, in comparison with the maximum values attained. The practical applications of these results could be in the area of chamber design, so that the effects of the length of the chambers be taken into account. That is, such greater lengths for the fluid in the chamber would involve larger pressures and consequently, greater stresses. However, the analysis should include an overall perspective, that is, the shortening of the chambers would imply an increase in the number of chambers, for a certain total payload, and the superposition effect of pressures, should be considered. On the other hand, the analysis could be extended to characterize the effects of the distribution of the lengths of the different chambers along the axis of the tanker, as the different resulting forces could have different effects on the pitch response of the road tanker. T2 - WCECS 2017 CY - San Francisco, CA, USA DA - 25.10.2017 KW - Tanker KW - Emergency KW - Braking PY - 2017 AN - OPUS4-42854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Otremba, Frank A1 - Romero-Navarrete, José A. A1 - Lozano Guzmán, A. A. T1 - Modelling of a Partially Loaded Road Tanker during a Braking-in-a-Turn Maneuver N2 - This paper describes a theoretical model to simulate the effects of a sloshing cargo on the safety performance of a vehicle that performs a braking-in-a-turn maneuver when travels at a partial fill level. The fundamental assumption of the model consists of the superposition of the effects of two simplified mechanical-analogy models that represent a liquid cargo on a vehicle, including one for the roll motion and another one for the pitch motion. The distinctive characteristics of the mechanical models, however, is that they are based upon a validated formulation to establish the properties of the pendulum (length). The results suggest a small effect of the sloshing cargo on the braking efficiency of the cargo, while the load transfer is moderately affected. However, such results should be put into a perspective, according to which such small variations can represent the avoidance of a rear-end crash or a rollover. In this respect, a specialized ABS system could be considered to improve the performance of such kind of vehicles when performing such maneuvers. Validation of the proposed methodology should be performed as a continuation of this research effort. KW - ABS KW - Braking-in-a-turn maneuver KW - Cargo sloshing KW - Road tankers KW - Load transfer KW - Simulation KW - Turning maneuvers PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-456908 VL - 7 IS - 45 SP - 1 EP - 14 PB - MDPI CY - Basel AN - OPUS4-45690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Romero-Navarrete, José A. A1 - Otremba, Frank T1 - Modelling of the lateral stability of river tankers N2 - A model of the cargo – ship interaction has been presented, for a navigation environment in which there is no waves, in which the ship lateral stability depends only on the manoeuver performed and the characteristics of the ship and cargo. Several simplifications have been introduced in the model, including the circular bottom of the ship, which facilitates the location of the buoyancy force on the ship, and the analogy of the sloshing cargo motion to a simple pendulum. Two forms of damping were introduced (river waters with the ship´s hull and the friction of the liquid inside the tanker walls), while the sliding motion of the ship when turning has been assumed as negligible. The results suggest that the sloshing cargo influences the lateral stability of the river tanker, with increases in the maximum roll angle from 15% to 40%, as a function of the speed and the fill level. The maximum roll angle has been found to occur at a 75% fill level, regardless of the ship speed. T2 - NAFEMS World Congress 2017 CY - Stockholm, Sweden DA - 11.06.2017 KW - Lateral stability KW - River tankers PY - 2017 SP - 1 EP - 11 AN - OPUS4-40669 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Würsig, Andreas A1 - Otremba, Frank T1 - Neue FVK-Tanks in den Unmodellvorschriften sowie Ergebnisse aktueller Forschungsvorhaben N2 - 100 mm of PUR-foam give satisfying results in terms of thermal properties. The non-pressure testing methods gives reliable and repeatable results. Bending modulus of laminates does not change until the first damage occurs. After that, the bending modulus decreases by 50 % but max. stress is still higher than at room temperature. T2 - 25. Gefahrgutkongress MV CY - Rostock, Germany DA - 19.10.2021 KW - FVK-Tanks KW - Unmodellvorschriften KW - Forschungsvorhaben PY - 2021 AN - OPUS4-53570 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erhard, Anton A1 - Otremba, Frank T1 - Nondestructive testing and fracture mechanics N2 - Nondestructive Testing (NDT) and fracture mechanics are two different disciplines in applied engineering science. Both areas are very important for the evaluation of the component integrity. Unfortunately the technical understanding in both disciplines is not identically, what lead to misunderstandings. In the present paper, the basic ideas about fracture mechanics and the input parameters coming from the NDT side are explained, concerning the integrity evaluation of the components. The widely used NDT methods are magnetic particle, dye penetrant, electrical eddy currents, radiography and ultrasonics. But not all of these common NDT methods can deliver parameters satisfy the fracture mechanics requirements. The first two can detect only surface-breaking or immediately sub-surface defects. Eddy current can also find defects in deeper sub-surface layers, while radiography and ultrasonics can also find embedded, remote defects. These three methods have furthermore a high potential for defect sizing and are therefore predestined to provide fracture mechanics input parameters. At the example of steam generator tube inspection the interplay of eddy current and fracture mechanics as related to tube integrity will be explained. T2 - 5th International CANDU In-Service inspection workshop and NDT in Canada 2014 conference CY - Toronto, Ontario, Canada DA - 16.06.2014 KW - Eddy current KW - Steam generator tube inspection KW - Component integrity KW - Fracture mechanics PY - 2014 SP - 1 EP - 12 AN - OPUS4-30907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bradley, I. A1 - Otremba, Frank A1 - Birk, A. M. A1 - Bisby, L. T1 - Novel equipment for the study of pressure vessel response to fire N2 - Pressurisation of full-containment pressure vessels in fire is known to be driven by thermal stratification. The predominant mode of heat transfer to the contents (convection from the shell to the liquid phase) results in formation of „hot“ boundary layers. Sub-cooled boiling may also be present. The warm layer rises to the surface through buoyancy and bubble flow, increasing the surface of the liquid above that of the bulk temperature, and hence driving a pressure rise. For reliable prediction of the complex effects governing vessel pressurization a three-dimensional numerical model is required. Work is being undertaken on such a model by other institutions in cooperation with this project. T2 - ASME 2016 CY - Phoenix, Arizona, USA DA - 11.11.2016 KW - Vessels KW - Novel equipment PY - 2016 AN - OPUS4-38433 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zur, Malte A1 - Otremba, Frank T1 - Numerical simulation and experimental study of cabin-airflow and mass transport of dangerous goods in aircraft cargo compartments N2 - Using plastic jerrycans or plastic containers, dangerous goods are transported as air freight in commercial aircrafts. Liquids or gases can escape by leakage or permeation effects from these plastic containers. The German Federal Institute for Materials Research and Testing (BAM) conducted prior research which showed that the lower explosion limit can be reached when transporting dangerous goods in sea-freight containers under normal transportation situations. The presented study is motivated based on these findings. The research objective of this study is to analyze the transportation situation of dangerous goods in cargo compartments of commercial airplanes. The scope of this paper is to present the experimental method used for validating a numerical model for CFD (Computational Fluid Dynamics) simulations and to present some simulation results of the mass transport of dangerous goods in the cargo compartment. The velocity profiles and the mass transport is calculated using numerical simulations and measured by Laser-Doppler-Anemometry (LDA) experiments. The mock-up is a generic model of a wide-body aircraft lower deck cargo compartment in a 1: 10 scale. Geometry, air exchange rates and inlet as well as outlet flow conditions in the cargo compartment are modeled using realistic boundary conditions. The commercial CFD (Computational Fluid Dynamics) code ANSYS CFX 14 is used for numerical flow simulations applying RANS (Reynolds-Averaged-Navier-Stokes) equations and turbulence models. The turbulence models studied are the renormalization group k-e-model (RNG), the BSL-Reynolds-Stress model (BSL) and the SST-k-co-model by Menter (SST). The flow measurement with LDA in the mock-up of a cargo compartment proves to be a feasible method for producing data to validate CFD simulations. Qualitative evaluation of the results shows a good overall agreement between numerical and experimental results. The experimental validation indicates that the implemented CFD model is capable of reproducing the flow situation in the model mock-up T2 - ICCEE 2015 - International conference on civil engineering and environmental engineering CY - Tokyo, Japan DA - 03.02.2015 PY - 2015 SP - 1 EP - 8 AN - OPUS4-32585 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Otremba, Frank A1 - Zur, Malte T1 - Numerical Simulation and Experimental Study of Cabin-Airflow and Transport of Gas-Mixtures in Aircraft Cargo Compartments T2 - International Conference on Civil Engineering and Environmenatal Engineering (ICCEE-616) CY - Tokyo, Japan DA - 2015-02-04 PY - 2015 AN - OPUS4-32528 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zur, Malte A1 - Klippel, Alexander A1 - Otremba, Frank A1 - Leder, A. T1 - Numerical simulation and experimental study of cabin-airflow and transport of gas-mixtures in aircraft cargo compartments: model validation N2 - Dangerous goods are transported as air freight in commercial aircrafts. Using plastic jerrycans or plastic containers, liquids or gases can escape by leakage or permeation effects. Prior research by the German Federal Institute for Materials Research and Testing (BAM) showed that the lower explosion limit can be reached when transporting dangerous goods in sea-freight containers under normal transportation situations. This motivated the presented study of the transportation situation of dangerous goods in cargo compartments of commercial airplanes. The scope of this paper is to present the experimental method used for validating a numerical model for CFD (Computational Fluid Dynamics) simulations. The CFD model will be used in a future study to evaluate the potential risk from transporting dangerous goods. The objective of this paper is to present the model mock-up of an aircraft cargo compartment and some examples of three dimensional velocity profiles of the air flow in the mock-up. The velocity profiles are calculated using numerical simulations and measured by Laser-Doppler-Anemometry (LDA) experiments. The mock-up is a generic model of a wide-body aircraft lower deck cargo compartment in a 1:10 scale. Geometry, air exchange rates and inlet as well as outlet flow conditions in the cargo compartment are modeled using realistic boundary conditions. The commercial CFD (Computational Fluid Dynamics) code ANSYS CFX 14 is used for numerical flow simulations applying RANS (Reynolds-Averaged-Navier-Stokes) equations and turbulence models. The turbulence models studied are the renormalization group k-ε-model (RNG), the Reynolds-Stress model by Launder, Reece and Rodi (LRR) and the SST-k-ω-model by Menter (SST). The flow measurement with LDA in the mock-up of a cargo compartment proves to be a feasible method for producing data to validate CFD simulations. Qualitative evaluation of the results shows a good overall agreement between numerical and experimental results. The experimental validation indicates that the implemented CFD model is capable of reproducing the flow situation in the model mock-up. T2 - ASME 2013 Fluids engineering summer meeting - 7th International symposium on flow applications in aerospace CY - Incline Village, Nevada, USA DA - 07.07.2013 KW - Computational fluid dynamics KW - Aircraft cabin air flow KW - Gas mixtures KW - Model validation PY - 2013 SN - 978-0-7918-5555-3 IS - Paper FEDSM2013-16622 SP - 1 EP - 9 AN - OPUS4-30076 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Fraňa, K. A1 - Attia, S. H. A1 - Otremba, Frank T1 - Numerical simulation of the filling process in the pressure bottle N2 - Parameter study for CFD in the bottle – grid resolution plays an important role on the temperature at the specific positions, 2D axi-symetrical calculation is a sufficient solution strategy in regards to the examined particular Problem. The intensity of filling process can be controlled by pressure “User defined function” provided by experiments. Numerical simulation demonstrated feasibility to predict temperature progress during the filling process successfully validated by experiments. The turbulent model k-w SST is the best strategy for the turbulent property calculations. The most intensive turbulent kinetic energy appeared in the middle region of the pressure bottle, the impact of the eddy viscosity on the wall was mostly in the wall region. T2 - ECMMM 2018 CY - Krakow, Poland DA - 10.02.2018 KW - Numerical simulation KW - Pressure bottle PY - 2018 AN - OPUS4-44177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -