Investigating Numerically the Effect of Wind on Fire Spread Between Two Informal Settlements Dwellings

Area of Science:

• Fire Science
• Urban Fire Dynamics
• Computational Fluid Dynamics

Background:

• Previous studies identified wind as critical in informal settlement fires.
• The specific influence of wind conditions on fire spread in these environments remains understudied.

Purpose of the Study:

• To investigate the effect of external wind conditions on fire spread between two closely spaced informal settlement dwellings.
• To analyze fire spread mechanisms, flashover, and heat transfer under varying wind speeds and directions.

Main Methods:

• Parametric numerical analysis using the Fire Dynamics Simulator (FDS) code.
• Benchmarking of numerical models against laboratory experiments.
• Simulations with wood crib fires under three wind speeds (6, 10, 14 m/s) and four directions (E, W, S, N).

Main Results:

• Wind speed and direction significantly impacted fire dynamics and spread between dwellings.
• Wind direction influenced flashover times, with delays observed when wind flowed between dwellings.
• Total heat transfer coefficient was directly proportional to wind speed; one wall's radiative heat transfer coefficient correlated with total heat transfer.

Conclusions:

• Wind conditions are complex but crucial factors in informal urban fire spread.
• Further research is essential to understand and mitigate wind's role in these fire scenarios.