TY - JOUR A1 - Schalau, Sebastian A1 - Michel, S. A1 - Plischka, H. A1 - Harms, F. A1 - Leitl, B. A1 - Schalau, Bernd A1 - Turnow, J. T1 - Simulation kurzzeitiger Gefahrstofffreisetzungen aus Industrieanlagen T1 - Simulation of short-term hazmat releases from industrial facilities - Challenges and possible solutions JF - Gefahrstoffe Reinhaltung der Luft N2 - Gefahrstofffreisetzungen aus technischen Anlagen können erhebliche Risiken für Mensch und Umwelt bergen und sind deshalb bei der Planung, der Genehmigung und im Regelbetrieb technischer Anlagen zu berücksichtigen. Zur Identifizierung von Gefahrenbereichen im Zusammenhang mit Gasfreisetzungen und zur Bewertung der Wirksamkeit von Schutzmaßnahmen werden Ausbreitungsrechnungen mithilfe verschiedener Modelle durchgeführt. Es werden zunehmend komplexere Berechnungsmodelle eingesetzt, die verlässlichere Prognosen liefern und helfen sollen, die Risiken durch windgetriebene Ausbreitung von Gasen weiter zu reduzieren. Mit steigender Komplexität der Simulationsverfahren steigen allerdings auch der Aufwand für die Entwicklung und die anwendungsbezogene Evaluierung neuer Modelle. Mit den vorgestellten Arbeiten wollen die Autoren einen Beitrag zur Entwicklung und Bereitstellung frei verfügbarer numerischer Strömungs- und Transportmodelle leisten und speziell die Weiterentwicklung der im Bereich Auswirkungsbetrachtungen verwendeten Werkzeuge unterstützen. Der Artikel beschreibt erste Problemlösungen auf dem Weg zur Entwicklung entsprechender, frei verfügbarer und angemessen validierter Softwaretools. N2 - Possible releases of hazardous materials from industrial sites pose substantial risks for people and the environment. Thus, they must be considered during planning, licensing, and operation of corresponding facilities. Different types of models are employed for identifying danger zones in the context of gaseous releases and to document the effect of protection measures. Numerical simulation tools of increasing physical complexity are utilized to obtain more reliable predictions and further reduce the risks associated gaseous hazmat releases. However, the increasing physical and Computational complexity of simulation tools is also raising the efforts needed for model development and application specific model evaluation. The work presented in this article is intended to foster the development of more sophisticated and freely available numerical flow and transport models, contributing to the further improvement of software tools available for respective consequence analysis and assessment. The article describes some first problems to be adequately addressed and solved on the way to a properly validated community modelling toolbox for near field dispersion of releases in complex industrial environments. KW - Gefahrstofffreisetzungen KW - CFD-Simulation KW - Turbulenzmodellierung KW - Windkanalmessungen PY - 2021 SN - 0949-8036 VL - 81 IS - 07-08 SP - 257 EP - 270 PB - VDI Fachmedien AN - OPUS4-53910 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schalau, Sebastian A1 - Habib, Abdel Karim T1 - Atmospheric wind field modelling with OpenFOAM for near-ground gas dispersion JF - Atmosphere N2 - CFD simulations of near-ground gas dispersion depend significantly on the accuracy of the wind field. When simulating wind fields with conventional RANS turbulence models, the velocity and turbulence profiles specified as inlet boundary conditions change rapidly in the approach flow region. As a result, when hazardous materials are released, the extent of hazardous areas is calculated based on an approach flow that differs significantly from the boundary conditions defined. To solve this problem, a turbulence model with consistent boundary conditions was developed to ensure a horizontally homogeneous approach flow. Instead of the logarithmic vertical velocity profile, a power law is used to overcome the problem that with the logarithmic profile, negative velocities would be calculated for heights within the roughness length. With this, the problem that the distance of the wall-adjacent cell midpoint has to be higher than the roughness length is solved, so that a high grid resolution can be ensured even in the near-ground region which is required to simulate gas dispersion. The evaluation of the developed CFD model using the German guideline VDI 3783/9 and wind tunnel experiments with realistic obstacle configurations showed a good agreement between the calculated and the measured values and the ability to achieve a horizontally homogenous approach flow. KW - OpenFOAM KW - Gas dispersion KW - Atmospheric boundary layer KW - Turbulence model PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539095 DO - https://doi.org/10.3390/atmos12080933 VL - 12 IS - 8 SP - 933 PB - MDPI AN - OPUS4-53909 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -