fd research applied to fire investigations …/media/9956bff9a03d40c8a1f694ecb5ae9752.pdf6/4/2017 1...

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Fire Dynamics Research Applied to Fire Investigations

Presented by:

Daniel Madrzykowski

Research Engineer

UL Firefighter Safety Research Institute

2017 NFPA Conference & Expo

Fire Investigation  What is the problem?

• Interpretation of fire patterns is one of the basic methods of determining the area of origin

• Currently there is  limited  scientific literature on the development of burn patterns.

“…much more research is needed on the natural variability of burn patterns…” 1

• “Experiments should be designed to put arson investigation on a more scientific footing.” 1

1. Strengthening  Forensic Science in the United States: A Path Forward, Committee on Identifying the Needs of the Forensic Sciences Community ; Committee on Applied Theoretical Statistics, National Research Council, National Academy of Sciences, 2009.

Overview

• Compartment Fire Dynamics– What is burning?– Fuel Vs. Ventilation Limited Fires– Convection vs Radiation– Fire Triangle ‐ based Analysis

• Fire Pattern Experiments– Fuel Limited – Repeatability– Ventilation Limited Structure Fires 

• Application• What’s Next

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Smoke is Fuel

Heat Release Rate Comparison

Cotton Synthetic

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Evolving Fuel Loads

Evolving Fuel Loads

Heat Release Rate

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Fire Pattern RepeatabilityFlame Height vs. Pattern Height

0.65 m 1.0 m

Mean Pattern Height = 0.83 m

Madrzykowski, D. and Fleischmann, C., Fire Pattern Repeatability: AStudy in Uncertainty, Journal of Testing and Evaluation, ASTM InternationalW. Conshohocken, PA.,Vol 40, No. 1, January 2012, pp 1-11.

Mean Flame Heights vs Fire Pattern Heights Values presented with 95% confidence limits 

Fire Dynamics in a Structure

Ideal Fuel Controlled Model Ideal Ventilation Controlled Model

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Flow PathsThe flow path is the volume between an inlet and  an outlet that allows the movement of heat, smoke and air from the higher pressure areas towards the lower pressure areas 

accessible via doorways and window openings. 

Single Compartment

Uni-directional Flow vents

Uni-directional Intake Uni-directional Exhaust

Bi-directional Flow vent

• A single vent serving as both an intake and exhaust vent.

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Neutral PlaneThe interface at a vent, such as a doorway or a window opening, between the hot gas flowing out of a fire compartment and the 

cool air flowing into the compartment.

The Impact of Ventilation on Room Fires in Full Scale StructuresUL FSRI Technical Panel

• Robert Byrnes, FDNY, New York• Steve Carmen, Carmen & Assoc., California• Paul Claflin, ATF, Alabama• Chris Connealy, SFM, Texas• Richard Dyer, Dyer Fire Consulting, Kansas• John Golder, ATF (ret.), North Carolina• Mark Goodson, Goodson Engineering, Texas• David Icove,  University of Tennessee• John Lentini,  Scientific Fire Analysis, Florida• Kevin McGrattan, NIST, Maryland• Michael Murphy, Chicago Fire Department, Illinois• James Novak, St. Paul Fire Department, Minnesota• Robert Pyzyna, Northbrook Fire Department, Illinois

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Impact of Ventilation – Structure Fires

Instrumentation

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Thermocouple Temperature Bi-Directional Probe – Temp & Pressure

Pressure and Oxygen ProbesOxygen & Pressure Sensors

Floor Plan

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LR1 Closed Temperature

LR1 Closed Pressure

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LR1 Closed Oxygen Concentration 1.2 m

LR1 Closed Oxygen Concentration  0.1 m

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LR2 Closed Temperature

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LR2 Closed Pressure

LR2 Closed Oxygen Concentration  1.2 m

LR2 Closed Oxygen Concentration  0.1 m

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Living Room Open Door

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Living Room,  Open Front Door

LR3 Open Temperature

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LR3 Open Pressure

LR3 Open Oxygen Concentration  1.2 m

LR3 Open Oxygen Concentration  0.1 m

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Bedroom 1 – Closed Door

Bedroom 2 – Open Door

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LR4 Open Temperature

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LR4 Open Pressure

LR4 Open Oxygen Concentration  1.2 m

LR4 Open Oxygen Concentration  0.1 m

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Single Story Experiments

• Living Room– All Exterior Doors & Windows Closed (2)

– Front Door Open (2)

• Kitchen– All Exterior Doors & Windows Closed (2)

– Front Door Open (2)

• Bed Room 1– Both BR1 Windows Open (2)

– Front Door & Both BR1 Windows Open (2)

Summary

• Fire patterns near area of origin repeatable

• Impact of ventilation repeatable 

• Fire patterns within the room of origin led to area of origin when considering the impact of ventilation

• Fire patterns generated pre‐flashed persisted post‐flashover if the ventilation points were remote. 

Coming soon

• Multi‐level impact of ventilation 

• Examination of Arc Fault Protection

• Validation study for FDS

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Further Needs 

• Fires with Fire Department “overhaul”

• Extended burn times

• Fire extension to the structure

• Impact of HVAC

• Some basics – matrix of thermal degradation conditions for painted gypsum board (new and old)

• Impact of time and ventilation

CFITrainer.net

Thank you

Follow us on Facebook & TwitterUlfirefightersafety@UL_FSRI

http://ulfirefightersafety.org/

daniel.madrzykowski@ul.com

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Recordings: Audio recordings of all sessions will be available free of charge via NFPA Xchange.

2017 NFPA Conference & Expo