The controlled burn experiments provide the fundamental understanding and data necessary to demonstrate the fire phenomenon, the factors involved, and their relative impact on fire behavior. Considering the cost, manpower, logistics, administration, and resources required to conduct the burn experiments, it is not viable to perform multiple live burns to quantify the findings of burn experiments for various scenarios and values of factors involved (e.g. different wind speeds, fire locations, structural features, fuel load, venting events etc.). Therefore, at NYU, the task of quantifying the impact of contributing factors on fire behavior is achieved through scientific numerical techniques via simulation software such as Fire Dynamics Simulator and Fluent. These computational numerical simulation-based analyses also verify the findings of burn experiments.
Using these software packages, researchers from NYU build fine-meshed models of structures tested in the burn experiment. Depending on the data obtained from the fire tests, the input conditions (such as heat source, fuel load, wind characteristics, thermal and atmospheric boundary conditions, structural characteristics, etc.) and the timeline of the live burns are entered into these computerized simulation tools. In response to the input factors, a transient thermal finite element analysis, (including radiation, convection, and conduction modes of heat transfer) is performed to obtain the values of pressure, temperature, heat flux, gas velocity, and flame spread across the entire computational domain at each instant. The output data of the simulations is analyzed and compared with the data of the burn experiments to verify the results of controlled fire tests.
Additionally, input conditions are varied to quantify the impact of contributing factors on fire dynamics. For example, the computational analysis was repeated for a wide range of wind speeds, wind directions, fuel loads, PPV fan specifications, door control techniques, structural characteristics, etc. to study their relative impact on fire behavior. This also helps the research team to establish size-up and tactical considerations for different fire scenarios. Complementing the results of fire tests using numerical simulation-based techniques provides an in-depth understanding of the phenomenon to firefighters and fire departments, as well as greater insight and larger data sets for more effective decision-making to fire protection engineers, scientists, and other stakeholders.