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Norwood, MA, United States

FM Global is a Johnston, Rhode Island-based mutual insurance company, with offices worldwide, that specializes in loss prevention services primarily to large corporations throughout the world in the Highly Protected Risk property insurance market sector. "FM Global" is the communicative name of the company, whereas the legal name is "Factory Mutual Insurance Company". FM Global has been named the "Best Property Insurer in the World” by Euromoney Magazine The company employs a non-traditional business model whereby risk and premiums are determined by engineering analysis as opposed to historically based actuarial calculations. This business approach is centered on the belief that property losses can be prevented or mitigated. FM Global engineering personnel regularly visit insured locations to evaluate hazards and recommend improvements to their property or work practices to reduce physical and financial risks if a loss occurs. Wikipedia.

Chaos M.,Factory Mutual Research Corporation
Fire Safety Journal | Year: 2013

In this study, sensitivity analyses are performed on a given pyrolysis model. An approach is presented, which involves complex-step differentiation, to compute the normalized first-order local sensitivity coefficients of relevant model outputs with respect to the inputs, i.e. the material properties. This approach is systematic and robust and provides sensitivity coefficients that are dynamic; that is, sensitivity values are given as a function of time for the entire pyrolysis process. In order to demonstrate the proposed methodology, the anaerobic thermal degradation of generic homogeneous materials (a semi-transparent non-charring material, simulating a thermoplastic, and an opaque charring material) exposed to heat flux levels leading to thermally thin and thermally thick material responses is considered. The dynamic sensitivities of mass loss rate and surface temperature are calculated and discussed. The information inferred from the sensitivity analyses presented herein can provide insights into the behavior of a given pyrolysis model and help reduce its complexity for specific applications. © 2013 Elsevier Ltd. Source

Xin Y.,Factory Mutual Research Corporation
Fire Safety Journal | Year: 2014

Quantification of heat release rate is crucial to many fire research works. Under certain conditions, such as very large fires and fire tests with sprinklers, measurements of fire heat release rate can be a challenging problem. This study attempted to develop a methodology of estimating chemical heat release rate using flame volume. This method is based on the theory that heat release rate per unit flame volume is relatively invariant, as long as the combustion is controlled by diffusion in buoyant fires under well-ventilated conditions. Test data were examined from a variety of fire experimental conditions to evaluate the proposed method. The results demonstrate that the flame-volume based method can provide reasonable estimation of heat release rate compared to oxygen-consumption based method. © 2013 Elsevier Ltd. Source

Dorofeev S.B.,Factory Mutual Research Corporation
Proceedings of the Combustion Institute | Year: 2016

Extinction in a turbulent non-premixed flame can lead to a local state or eddy where the fuel, oxidizer and combustion products are mixed together. The process of quenching and re-ignition of these eddies in turbulent non-premixed flames is analyzed. The corresponding critical conditions are first related to the eddy Damköhler number, and then, through the spectrum of the mixed eddy sizes, to the turbulent Karlovitz number of the flow and the properties of the stoichiometric pre-mixture in the eddy. It is shown that the mixed eddies at the reaction length scale are the most reactive, and there is a continuous range of reaction completeness between the overall quenching and re-ignition. Based on the spectrum of eddy sizes in the flow, a local volume fraction of reactive eddies is defined that can be used as a factor in the expression of the reaction rate in turbulent non-premixed combustion models. Representative chemical kinetic properties necessary to implement this approach in fire modeling are introduced. The model predictions are compared with test data on quenching by dilution, blow-off extinction limit, and extinction strain rate as a function of diluent type and concentration. © 2016 The Combustion Institute. Source

Zhou X.,Factory Mutual Research Corporation
Proceedings of the Combustion Institute | Year: 2015

One important aspect of the complex sprinkler protection process is the interaction between the water spray and the fire plume. In order to provide suitable data for the development and validation of a LES-based fire protection models, such as FireFOAM, a series of small-scale experiments were conducted to examine the interaction of hot air plumes and water sprays through combined gas-liquid velocity and droplet size measurements. Laser-based particle image velocimetry (PIV) was used to acquire the spatially-resolved velocity data; and a shadow imaging system (SIS) was used to measure the water droplet size and volume flux. Hot air plumes with three convective heat release rates (1.6, 2.1 and 2.6 kW) were selected to interact with a water spray at a discharge rate of 0.084 Lpm. The velocity field of the hot air plume and ceiling flow with/without water spray, the droplet size and volume flux of water spray with/without hot air plume were measured. The interaction between the hot air plume and water spray was characterized by the location of the interaction boundary with the momentum ratio of the hot air to that of the spray. The results showed that that the momentum ratio and the evaporation effect due to hot air on the water droplets played a significant role to change the interaction structure and the ceiling layer pattern. © 2014 The Combustion Institute. Published by Elsevier Inc. All rights reserved. Source

Yu H.-Z.,Factory Mutual Research Corporation
Fire Safety Journal | Year: 2012

Based on the Froude modeling concept, Heskestad proposed a set of scaling relationships for the sprayplume interaction for high droplet Reynolds number conditions (10≤Re d≤500). The droplet Reynolds number is defined as the ratio of the product of droplet diameter and the absolute value of the droplet velocity relative to the gas velocity over the gas kinematic viscosity. The aforementioned scaling relationships have been used widely for scale-modeling of water-based fire protection under conditions within or beyond 10≤Re d≤500. Recently, it was shown that the same scaling relationships can be extended to low droplet Reynolds number conditions of Re d≤1 except that the droplet size is scaled with the 1/4-power of the scale ratio, instead of the 1/2-power for 10≤Re d≤500. The conditions of 10≤Re d≤500 in general prevail in sprinkler applications and the conditions of Re d≤1 usually take place in water mist applications. With the above difference in mind, the Froude modeling is revisited in this paper to establish a set of general scaling relationships not limited to specific droplet-Reynolds-number regimes. The derived general relationships not only reproduce those for Re d≤1 and 10≤Re d≤500, but also reaffirm the previous finding that the scaling relationships are independent of the scale ratio except for the droplet size, whose scaling requirement varies with the range of Re d values in which the scale-modeling is performed. The published experimental results to date show that the Froude-modeling-based scaling relationships for sprayplume interaction are a viable tool for scale-modeling of the fire suppression or extinguishment by water sprays. © 2011 Elsevier Ltd. All rights reserved. Source

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