6/4/2017 1 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
Transcript
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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 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
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