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 - Underground gas pipeline explosion and fire: CFD based assessment of foreseeability N2 - Scenarios of underground gas pipeline failure, crater formation, dispersion of gas, explosion and subsequent fires are investigated with semi-empirical and with CFD (Computational Fluid Dynamics) modelling. In order to strengthen the accident based learning approaches present investigations are performed in the context of recent GAIL (Gas Authority of India Limited) natural gas pipeline incident occurred in India. The foreseeability of damages to lives of people and assets due to explosion overpressure and thermal radiation are assessed. The released gas is considered as slightly dense-than-air i.e. 1.5 times. Depending on the LFL (Lower Flammability Limit) of gas the dispersion diameter and heights are predicted which followed the visual evidences appropriately. The model was furthermore tested with an even denser medium and was found to be worked well there too. The estimated explosion overpressures with the standard methods and also with CFD reproduced the scenario nicely. The effects of congestion VBR (Volume Blockage Ratio) in form of vegetation on stable atmospheric boundary layer flow is analysed and its contribution towards turbulence and hazard enhancement is studied. It is found that the major source of fatalities was higher thermal radiation emitted by pool fires of methane. The estimated thermal safety distances clearly demonstrate the ignorance/under estimation of likelihood and consequence of such hazardous events. For such incidents CFD demonstrated a strong capability to assess the pre or/and post events foreseeabilities within a reasonable amount of time and with an acceptable level of accuracy meeting the industrial needs for risk analysis. KW - Natural gas KW - Underground pipeline KW - Dense gas dispersion KW - Explosion and fire KW - CFD KW - Safety distance PY - 2015 DO - https://doi.org/10.1016/j.jngse.2015.04.010 SN - 1875-5100 VL - 24 SP - 526 EP - 542 PB - Elsevier CY - Amsterdam [u.a.] AN - OPUS4-33671 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter A1 - Schönbucher, A. T1 - Pool and tank fires - Are we really prepared? N2 - The industrial fire accidents e.g. Buncefield (2005) and Jaipur (2009) have come up with several issues concerning safe storage and transportation of flammable liquids. The pre and post fire consequences are therefore important to be analyzed prior to the handling of flammable fuels. Pool or/and tank fire is the most often seen scenario after the leak/spill of liquid fuel. An overview of the typical scenarios from large hydrocarbon and organic peroxide pool fires and their respective safety distances for the people and the infrastructure are the important subjects of this paper. T2 - 8th Asia-Pacific conference on combustion CY - Hyderabad, India DA - 2010-12-10 KW - Flammable liquids KW - Pool fire KW - Safety distance KW - Organic peroxides PY - 2010 SP - 697 EP - 702 AN - OPUS4-23004 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mishra, Kirti Bhushan A1 - Wehrstedt, Klaus-Dieter A1 - Krebs, Holger T1 - Amuay refinery disaster: The aftermaths and challenges ahead N2 - Amuay refinery disaster (2012) is another recent example of Vapor Cloud Explosion (VCE) and fire accidents preceded by Buncefield (2005), Puerto-Rico (2009) and Jaipur (2009), respectively [9]. The incident has left many safety issues behind which must be repeatedly addressed. Unfortunately, the lessons taught by previous similar events are just not understood carefully. It reveals that the proper safety measures for such facilities were either underestimated or were not accounted seriously. Consequently, the resulting overpressures from explosion and the subsequent thermal radiation from tank fires have once again proved to be disastrous to both mankind and infrastructure. This article highlights the aftermaths of Amuay incident and addresses the challenges put forward by it. Furthermore, a comparative study is performed between such incidents to analyze the similarities and how they could have been avoided. KW - Refinery disaster KW - Vapor cloud explosion KW - Fire KW - Safety distance KW - Overpressure KW - Radiation PY - 2014 DO - https://doi.org/10.1016/j.fuproc.2013.10.025 SN - 0016-2361 SN - 0378-3820 SN - 1873-7153 VL - 119 SP - 198 EP - 203 PB - Elsevier CY - Amsterdam AN - OPUS4-29816 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -