Fire modeling provides mathematical and scientific research into the behavior and problems associated with fire.  Fire modeling is a useful tool for any area of fire safety, especially fire protection engineering, fire investigation, and fire suppression.

Once you complete the Week 7 readings, write a post to achieve the following:

1. Briefly discuss the history and origin of fire modeling and why it has become an important tool in the fire service, especially in the fields of fire engineering and fire investigation.
2. Briefly discuss the difference between a zone model and a field model.
3. Read the article “The Use of Simulation in Fire Investigation” and briefly discuss how the Zone Model – Consolidated Model of Fire Growth and Smoke Transport (CFAST) and the Field Model – Fire Dynamics Simulator (FDS), differed in their experiment.  
4. Read the “NIST Technical Note 1856” found in this week’s readings and then discuss the following:
a. Summarize the incident
b. Discuss the model used for the simulation
c. Discuss the results of the simulation

#1

The history of fire modeling can be traced back to the early 1940’s when mathematical and science formulas were developed to validate or refute how fire patterns developed. Beginning in 1975 fire modeling began to increase across the country as more and more universities and private sector companies such as laboratories utilized fore modeling to research fire patterns and behavior for safety related purposes (Nelson 2002).

The difference between a zone model and a field model can be best described as the field model being much more calculation intensive then a zone model. A zone model basically approximates a fire condition in a fire room based on a consistent gas layer with a heat source. A field model utilizes calculations to measure things such as heat and temperature (NIST 2007). Fire modeling is very helpful in planning for safety in future fire situations.

The article “The Use of Simulation in Fire Investigation” revealed that using both the zone model and the field model proved to be beneficial for future fire safety. The main difference appears to be that the Consolidated Model of Fire Growth (CFAST) (Zone model) was more accurate than the field model fire dynamic simulator (FDS) The article makes mention that both models proved beneficial but the CFAST was more accurate than the FDS model.

“NIST Technical Note 1856”

The report reviews an incident that occurred on June 2, 2011 in a residential basement fire in San Francisco California that resulted in the death of two San Francisco firefighters. The fire model utilized to research the incident was a Fire Dynamics Simulator (FDS) model, which is a field model type of fire modeling and is the most popular type of field modeling. The research of the fire utilizing the simulations summarized that the two fire fighters were caught in the flow path of the fire traveling from the basement to the front open portion of the fire building. The firefighter’s injuries from being caught in the flow path resulted in their deaths.

References

NIST Modeling Study Reveals the Lethal Dynamics of a San Francisco House (2015,      January 30).    Targeted News Service. Retrieved from http://search.proquest.com/docview/1649680789/

#2

1. Many in the fire profession would state that the use of mathematics and science as applied to fire-related dynamics began in the early 1940’s (Nelson, 2002).  As a result of this relatively recent application of math to fire dynamics, most scientists would call the profession/science young and relatively undeveloped. It is essential because it can show the characteristics of the fire and can help the investigator put the pieces together.

2. The zone model breaks down the compartment into two or three zones. Mostly they are the upper layer and the lower layer. Usually, the top layer is the hot gases and smoke, while the lower layer has cool air. It will show different aspects of the fire and how the two layers affect each other. Field models, or computational fluid dynamics (CFD) models, provide a method for modeling the fluid flow through a volume using numerical solutions of the Navier-Stokes equations. (Vigne, 2017)

3. During the simulation, the CFAST was the more accurate of the two, but both models helped attain the information learned.
4. San Francisco Fire Department was dispatched to an electrical fire on the morning of 2 June 2011. While searching for the seat of the fire, two firefighters ended up dying. The simulator was a field model called the CFD model.

References

Vigne, G. (2017, April 25). An Introduction to Fire Modelling. Retrieved from http://www.fireng.org/p/introduction-to-fire-modelling.html.