Towards a simplified fire dynamic simulator model to analyse fire spread between multiple informal settlement dwellings based on full-scale experiments

摘要

This paper develops a Fire Dynamics Simulator (FDS) model to analyse fire spread for informal settlements, based upon full-scale experiments. Informal settlements are frequently ravaged by fires, leaving thousands of people homeless, and with more than 1 billion people residing in informal settlements, there is a significant need to understand and improve the fire safety in such areas. Due to high levels of uncertainty inherent with input parameters regarding informal settlements, this work also investigates the sensitivity of fire behaviour to the input parameters used in numerical simulations. It is shown that spread times between two dwellings can vary from 1 minute after flashover to no spread at all, depending on the simulation input parameters selected. This paper highlights the importance of such input parameters when trying to model fire spread between dwellings. The simulations indicate that a simplified fire spread model for informal settlements is possible, especially for steel clad dwellings, however it showed that significant work is required for timber clad dwellings, that is, because the rate at which additional ventilation forms in the simulation for the timber clad dwellings is significantly slower than reality, which is as a result of the simplifications made. The simplification of using heating, ventilation, and air conditioning (HVAC) systems to model leakages, resulting from the corrugated flutes, showed good enclosure fire dynamics behaviour compared to the experiments, but created new challenges with regards to the spread mechanism, since HVAC systems do not allow electromagnetic waves to penetrate in the same manner as an opening.