A fire modeling expert can test forensic fire investigation hypotheses, consistent with the Scientific Method in NFPA 921, Guide for Fire and Explosion Investigations, to determine whether a postulated fire origin and cause is scientifically valid. Similarly, some aspects of liability or responsibility can be assessed by a fire modeling expert. Since fire models are complex computer programs that solve coupled sets of mathematical equations encoding the physical laws of nature governing fire dynamics, a fire modeling expert must have considerable education, training, or experience to correctly apply a fire model. Although fire modeling makes it possible for fire modeling experts to analyze and reconstruct fires, fire modeling cannot be used to “prove” an origin; however, fire modeling can be used to determine if a postulated origin and cause is consistent with the available forensic evidence or should be eliminated due to contradictions with the same.Fire modeling produces graphical representations of fire conditions (smoke concentration, temperature, flame position) that can effectively convey technical information to the layperson. Some of the more common fire modeling applications encountered in forensic fire reconstruction include:
- Analysis of whether a postulated fire origin is consistent with forensic evidence including fire patterns, witness or first responder statements, fire alarm records, and fire photographs
- Analysis of whether a postulated fire cause is consistent with the known fire timeline
- Fire development modeling (how fast did a fire spread and how intense did it become)
- Smoke detector and heat detector activation modeling (how long did it take for smoke or heat detectors to activate)
- Tenability analysis (how much smoke, heat, and toxic gases were present at various locations and would the conditions cause occupants to become incapacitated)
- Establishment of a fire time line (to determine major events such as ignition, detector activation, onset of flashover, window breakage, spread to adjacent rooms or areas, etc.)
- Egress modeling (how long would it take occupants to evacuate a given space)
Dr. Chris Lautenberger is Reax Engineering’s primary fire modeling expert with over 10,000 hours of experience developing, testing, and applying fire models in support of scientific research, forensic fire analysis, and fire protection engineering design. His MS thesis and PhD dissertation both focused on fire modeling, and Chris has published several peer-reviewed journal articles on various aspects of fire modeling. Lautenberger currently teaches a graduate-level course on Fire Modeling in the Department of Fire Protection Engineering at California Polytechnic State University in San Luis Obispo. Chris regularly conducts fire modeling to analyze various aspects of fires and explosions, and often critiques analyses conducted by other fire modeling experts to determine if a fire model has been mis-applied due to inexperience, lack of training/education, failure to recognize model limitations, or questionable assumptions.
