TY - CONF A1 - Mishra, Kirti Bhushan T1 - Investigations of BLEVE (Boiling Liquid Expanding Vapour Cloud Explosion) and fireballs of peroxy-fuels and hydrocarbons: Experiments and CFD simulation T2 - 12th International Conference on Combustion and Energy Utilisation (ICCEU) CY - Lancaster, England DA - 2014-09-29 PY - 2014 AN - OPUS4-31585 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishra, Kirti Bhushan T1 - Rheinland refinery accident 2014: CFD prediction of atmospheric dispersion of smoke T2 - Combustion Research and Application 2014 CY - Soesterberg, Netherlands DA - 2014-10-08 PY - 2014 AN - OPUS4-31586 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schmidt, Simon A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter T1 - CFD simulations to predict the thermal safety distances from jet fires of peroxy-fuels N2 - CFD (Computational Fluid Dynamics) simulations have been carried out to investigate the behavior of turbulent, subsonic jet fires of the peroxy-fuel Di-tert-butyl peroxide (DTBP) using the SAS-SST turbulence model, the discrete transfer radiation model, the eddy dissipation combustion model and the Magnussen soot model. Safety relevant parameters, such as flame length, temperature and thermal radiation are predicted to give recommendations on safety distances. T2 - 4. Magdeburger Brand- und Explosionsschutztag / 3. vfdb-Workshop Brandschutzforschung CY - Magdeburg, Germany DA - 26.03.2015 KW - CFD simulations KW - Thermal safety distances KW - Jet fires KW - Peroxy-fuels PY - 2015 SN - 978-3-00-048960-0 SP - 1 EP - 12 AN - OPUS4-33283 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter T1 - Rheinland refinery accident 2014: CFD prediction of atmospheric dispersion of smoke N2 - Industrial fire and explosion hazards are most often also associated with the dispersion of toxic substances. These substances can be gases, liquids, solids or in form of aerosols. The critical toxic exposure limits to People and enviroment from such substances are regulated by the concerned authorities of the countries. In order to comply with the defined regulation estimation of such critical limits must be carried out by different semi-empirical and phenomenological models/methods for risk assessment. Many of such methods provide a qualitative estimation of time and space dependent extrimities of toxicity. The overwhelm development of computational capacity has made it possible to perform Computational Fluid Dynamics (CFD) simulation by solving the three-dimensional transport equations for mass momentum and species in lower and upper atmosphere, respectively. CFD simulation not only provides a detailed 3D distribution of toxic particulates/gases in the neighbourhood of the plant but also helps to study the worst-case sceanrios. In the past several small- and large-scale accidents occured in oil and gas plants in different parts of the world including the recent one in Rheinland refinery near Cologne in Germany. This work deals with this accident and provides a methodology to predict the critical exposure limits of smoke emitted by a toluene tank fire by means of CFD simulation. T2 - COMBURA 2014 - Combustion research and application symposium CY - Soesterberg, The Netherlands DA - 08.10.2014 KW - CFD KW - Retinery incident KW - Smoke dispersion PY - 2014 SP - 56 EP - 57 AN - OPUS4-31721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishra, Kirti Bhushan T1 - An overview of recent research activities at BAM 2.2 T2 - IGUS EOS Meeting CY - Nanjing, China DA - 2014-04-09 PY - 2014 AN - OPUS4-30555 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter T1 - Spill-over characteristics of peroxy-fuels: Two-phase CFD investigations N2 - Two-phase CFD (Computational Fluid Dynamics) model for characterising the spill-over/dispersion of peroxy-fuels is presented. The model is independent of type and burning rate of the spilled/dispersed fuel and considers only overflow Reynolds number (Re) to characterise the spill/dispersion behaviour. Additional simulations are performed for LNG (Liquified Natural Gas) dispersion and it is found that the model can be used for different fuels within a defined range of Re. Different scenarios with Re = 100 to 3 × 105 are investigated covering a wide range of mass flow rates, opening sizes and viscosities. Depending on Lower Flammability Limits (LFL) of the fuels spill/dispersion (vapour cloud) diameters (DCFD) and heights (hCFD) are predicted. A generalised correlation between DCFD and Re is established to predict the dispersion occurring at varying scales. The model is validated by: (1) conducting an extensive grid independent study; (2) comparing the results with the existing analytical methods and (3) comparing against the standard field test data on LNG dispersions. KW - Spill-over KW - Dispersion KW - Peroxy-fuels KW - CFD KW - Reynolds number KW - Liquefied natural gas PY - 2014 DO - https://doi.org/10.1016/j.jlp.2014.02.014 SN - 0950-4230 SN - 1873-3352 VL - 29 SP - 186 EP - 197 PB - Butterworth CY - Guildford, Surrey AN - OPUS4-30481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Malow, Marcus A1 - Wehrstedt, Klaus-Dieter A1 - Mishra, Kirti Bhushan A1 - Steinbach, J. T1 - Thermische Zersetzung von AIBN - Experimente und Simulationen zur Bestimmung der SADT N2 - Die thermische Zersetzung von AIBN wurde in einem Projekt mit mehreren Teilnehmern untersucht. Hierbei wurde die selbstbeschleunigende Zersetzungstemperatur SADT) sowohl experimentell als auf Grundlage von Simulationsrechnungen bestimmt. Die Besonderheit bei dem Feststoff AIBN ist, dass die Zersetzung sowohl in der festen, als auch in der flüssigen Phase nach dem Schmelzen stattfindet, was bei den durchgeführten Simulationsrechnungen berücksichtigt werden musste. Die berechneten SADT Werte stimmen mit den experimentell bestimmten sehr gut überein. T2 - 14. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Berlin, Germany DA - 14.06.2016 KW - SADT KW - Reaktionskinetik KW - AIBN KW - DSC KW - UN-Test H.1 KW - UN-Test H.4 PY - 2016 SN - 978-3-9817853-5-7 SN - 0938-5533 SP - 54 EP - 59 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-37878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Blankenhagel, Paul A1 - Wehrstedt, Klaus-Dieter A1 - Mishra, Kirti Bhushan A1 - Steinbach, J. T1 - Feuerbälle organischer Peroxide: Thermische Strahlung und Sicherheitsabstände N2 - Das Abbrandverhalten und die thermische Strahlung von Poolfeuern organischer Peroxide (OP) wurden bereits in der Vergangenheit ausführlich untersucht. Dabei ergaben sich zum Teil erhebliche Unterschiede hinsichtlich der Abbrandraten, Temperaturen, Strahlungsintensitäten und Flammenlängen im Vergleich zu flüssigen Kohlenwasserstoffen. Das größere Gefahrenpotenzial von OP führt zu strikteren Sicherheitsbestimmungen für Lagerung und Transport. Da das Gefahrenpotenzial maßgeblich von den tatsächlich auftretenden Szenarien abhängt, ist eine Bewertung solcher Ereignisse unumgänglich um nachhaltig die Gesundheit von Mensch und Umgebung zu sichern. Ein Metallfass, gefüllt mit 200 Litern DTBP (Di-tertiär-butylperoxid), wurde auf dem Testgelände Technische Sicherheit der BAM einem Außenfeuer ausgesetzt. Durch den starken Wärmeeintrag erhöht sich die Massenabbrandrate des Peroxids um ein Vielfaches und das Fass entleert sich schließlich unter Ausbildung mehrerer Feuerbälle. Die Flammengröße, Flammentemperatur und damit die thermische Strahlung überschreiten die der gewöhnlichen OP-Poolfeuer. Die resultierenden höheren Sicherheitsabstände sind abschließend berechnet. T2 - 14. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Berlin, Germany DA - 14.06.2016 KW - DTBP KW - Feuerbälle KW - Organische Peroxide KW - Thermische Strahlung PY - 2016 SN - 978-3-9817853-5-7 SN - 0938-5533 SP - 126 EP - 133 PB - Bundesanstalt für Materialforschung und -prüfung (BAM) CY - Berlin AN - OPUS4-37881 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishra, Kirti Bhushan T1 - CFD model for large hazardous dense cloud spread predictions, with particular reference to Bophal disaster N2 - A volumetric source based CFD (Computational Fluid Dynamics) model for estimating the wind and gravity driven spread of an elevated released dense hazardous cloud on a flat terrain without and with obstacles is demonstrated. The model considers the development of a worst-case scenario similar to that occurred at Bhopal. Fully developed clouds of a dense gas having different densities, under ABL (Atmospheric Boundary Layer) with calm ground wind conditions are first obtained. These clouds are then allowed to spread under ABL with different ground wind speeds and gravity conditions. The developed model is validated by performing the grid independent study, the fluid dynamical evidences, post-disaster facts, the downwind MIC (Methyl Isocynate) concentrations estimated by earlier models and experiments on dense plume trajectories. It is shown that in case of an active dispersion under calm wind conditions the lateral spread would prevail over the downwind spread. The presence of a dense medium behaves like a weak porous media and initiates turbulence at much smaller downwind distances than that normally would occur without the dense medium. The safety distances from toxic exposures of MIC are predicted by specifying an isosurface of a minimum concentration above the ground surface. Discrepancies in near-field predictions still exist. However, the far-field predictions agree well with data published before. KW - CFD model KW - Dense cloud KW - Safety distance KW - Porous medium KW - Bhopal disaster PY - 2015 DO - https://doi.org/10.1016/j.atmosenv.2015.06.038 SN - 0004-6981 SN - 1352-2310 VL - 117 SP - 74 EP - 91 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-33807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter T1 - Diffusive burning of blended peroxy-fuels: Some experimental results N2 - Dampening of energetic properties and the effects of blending proportions of isododecane on the diffusive burning behaviour of peroxy-fuels are experimentally studied. Blended peorxy-fuels are obtained by adding isododecane in the proportions of 25 wt.%, 50 wt.% and 75 wt.%, respectively, in technical pure peroxy-fuels. The fuels were burned in form of pool fires with diameters 0.02 m ≤ d ≤ 1 m. The mass burning rates and relative flame lengths are found to be weakened with increasing diluent proportions. By measuring the mass burning rates and visible flame lengths of pool fires of different samples of fuel blends an optimum blending criterion is developed. Furthermore, it is shown that the dilution proportions and flame characteristics can be correlated by empirical equations. KW - Peroxy-fuels KW - Blends KW - Isododecan KW - Pool fire KW - Mass burning rate KW - Flame length PY - 2015 DO - https://doi.org/10.1016/j.fuproc.2015.06.014 SN - 0016-2361 SN - 0378-3820 SN - 1873-7153 VL - 140 SP - 324 EP - 330 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-34950 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -