Fire dynamics and modelling
“Fire dynamics” is about the physics and chemistry of fires. This work package can be regarded as more fundamentally oriented than the other WPs. Physical interactions are formulated in terms of models, and models are calibrated and validated against experimental data.
At the time we have three projects running or planned:
Project 2.1 - Modelling of turbulence-chemistry interactions at reduced oxygen concentrations
Underventilated fires occur in enclosed space, where the fire consumes much of the air oxygen. The lowered oxygen concentrations will reduce temperature and reaction rate (increase chemical time scale). Moreover, the flames may have weaker turbulence (lower turbulence Reynolds numbers) than the standard turbulence and turbulence-combustion models are developed for. Validation of sub-models will be based primarily on experimental data from literature and partners, supplemented by theoretical considerations and comparison with more advanced and detailed models. One PhD-candidate will be engaged in this project.
Project 2.2 - Smouldering: effects of cooling
Recently, cooling has been demonstrated at a small scale as a potential new method for combating smouldering fires. By using a water purged cooling pipe, direct fuel-to-water contact is avoided. As a consequence, swelling of the fuel is avoided as well as channelling of extinguishing agent, scattering of glowing embers and water run-off to the environment. Cooling on the outside of the sample will also be of interest.
Project 2.3 - Pyrolysis, gasification and formation and dispersion of toxic gases and fumes from fires
The formation of gases and fumes from fires is of importance for health and life. It is also an input to simulation models (cf. Project 2.1). Initially, we will identify experimental data and models from literature that provide relevant input. Some of the processes, particularly in under-ventilated fires, are closely related to those of smouldering (Project 2.2) and will be studied in this context. Moreover, knowledge from energy-based solid fuel combustion will be utilized and developed for the purpose. This project is estimated to start in the beginning of the centre’s third year.
Ivar S. Ertesvåg, NTNU