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Kuldeep R. Prasad, Anthony Bova, James R. Whetstone, Elena Novakovskaia
Currently, inverse atmospheric dispersion models are being used around the world to provide measurement-based, or top- down, estimates of greenhouse gas (GHG) emissions for comparison with input-based, or bottom-up, estimates. To minimize uncertainty
Randall J. McDermott, Hyun Wook Park, Kiyoung Moon, Ezgi Oztekin, Changhoon Lee, Jung-il Choi
A well-known challenge for large eddy simulation (LES) is to provide a smooth transition from molecular to turbulent transport near the wall without having to explicitly resolve the viscous sublayer. We propose a simple but efficient approach based on
Richard D. Peacock, Thomas G. Cleary, Paul A. Reneke, Daniel Murphy
A review is presented of the state of the art of smoke production measurement, prediction of smoke impact as part of computer-based fire modeling, and measurement and prediction of the impact of smoke through deposition of soot on and corrosion of
Fire simulation tools are used frequently in the fire safety assessment of nuclear and other industrial installations. They are also used in the context of probabilistic fire risk assessment as deterministic models providing the relation between the random
Amanda P. Robbins, Erica D. Kuligowski, Steve M. Gwynne
A systematic approach to the identification of fire-safety scenarios for analysis is desirable in order to identify important scenarios and to help ensure a consistent approach for different analysts. The number of possible fire-safety scenarios in any
Kevin B. McGrattan, Randall J. McDermott, Glenn P. Forney, Jason E. Floyd, Simo A. Hostikka, Howard R. Baum
An overview of a methodology for simulating fires and other thermally-driven, low-speed flows is presented. The model employs a number of simplifications of the governing equations that allow for relatively fast simulations of practical fire scenarios. The
Kuldeep R. Prasad, William M. Pitts, Marco G. Fernandez, Jiann C. Yang
Increase in the number of hydrogen fueled applications in the marketplace will require a better understanding of the potential for fires and explosion associated with the unintended release of hydrogen within a structure. Predicting the temporally evolving
Jiann Yang, William M. Pitts, Marco Fernandez, Kuldeep Prasad
An experimental apparatus, which was based on the ¿-scale garage previously used for studying helium release and dispersion in our laboratory, was used to obtain effective diffusion coefficients of helium and hydrogen (released as forming gas for safety
Realistic visualization methods are important for applications where one wishes to observe data effects rather than examine data quantitatively. This note documents how the radiation transport equation (RTE) and associated numerical algorithms are used by
In this paper, we examine the emerging field of \emph{quality assessment} for large-eddy simulation of fire dynamics. The importance of model convergence is discussed and the differences between validation and quality assessment are highlighted. Briefly
The purpose of this report is to update calculations, originally performed in 1993, that predict the downwind extent of smoke particulate from hypothetical in situ burns of spilled crude oil in Alaska. The reason for the update is that the National Ambient
Randall J. McDermott, Kevin B. McGrattan, Jason E. Floyd
A reaction time scale model is developed for use in the eddy dissipation concept (fast chemistry limit) closure of the mean chemical source term in large-eddy simulation of fires. The novel aspect of the model is to consider a scaling regime for coarse
An improved flame extinguishing criterion is implemented to the Fire Dynamics Simulator (FDS) for gaseous suppressants under the lumped species model with transport-limited combustion (infinitely fast chemistry). The criterion considers the total enthalpy
Jason D. Averill, Erica D. Kuligowski, Richard D. Peacock
This article reviews the history of egress design and code requirements in the United States, describes the current state-of-the-art in egress design and modeling, and offers a strawman research agenda for future egress research.
Kuldeep R. Prasad, William M. Pitts, Jiann C. Yang
Development of the hydrogen economy will require a better understanding of the potential for fires and explosions associated with the unintended release of hydrogen within a structure. The ability to predict the mixing and dispersion behavior of hydrogen
A methodology is proposed for reporting the results of fire model validation studies that consist mainly of comparisons of model predictions and experimental measurements. The difference between the two is a combination of model error and experimental
Strategies are developed that make use of signals from smoke and heat alarms to deduce conditions in a room for both flaming and smoldering fires. The issue addressed is to determine how to provide useful information to incident command for smoldering
In a direct-forcing immersed boundary method, first introduced by Fadlun et al. (2000), the momentum equation is supplemented by a force term which drives the local velocity to a specified value. The method has gained popularity due to its ease of
Kevin B. McGrattan, Randall J. McDermott, William E. Mell, Glenn P. Forney, Jason E. Floyd, Simo A. Hostikka
A methodology is described for representing complicated objects within a computational fluid dynamics model. These objects are typically collections of similar items that are too small to define on the numerical grid that is used to solve the governing
Randall J. McDermott, Glenn P. Forney, Kevin B. McGrattan, William E. Mell
The Fire Dynamics Simulator (FDS) and Smokeview (SMV) are computational and visualization tools specifically designed for large-eddy simulations (LES) of low-speed, thermally driven flows \cite{fds-smv}. FDS Version 6 will offer improvements in the
William E. Mell, Samuel L. Manzello, Alexander Maranghides, David T. Butry, Ronald G. Rehm
Wildfires that spread into wildland-urban interface (WUI) communities present significant challenges on a number of fronts. In the United States the WUI accounts for a significant portion of wildland fire suppression and wildland fuel treatment costs
Jeffrey W. Bullard, Chiara C. Ferraris, Edward Garboczi, Nicos Martys, Paul E. Stutzman, Judith E. Terrill
Design and optimization of cement or concrete mixes typically is accomplished by intensive trial-and-error experimentation, primarily because the design space has many parameters and because interactions between these parameters are incompletely understood
The NRC is developing guidance for performing quantitative human reliability analysis for post-fire mitigative human actions modeled in a fire probability risk assessment. In some of the scenarios, operators are assumed to be exposed to the fire effluent
We perform calculations of 2D laminar and 3D turbulent channel flow with periodic streamwise boundary conditions. From the laminar results we verify that the FDS wall boundary condition is second-order accurate. For the turbulent cases we adapt the wall