Characteristic parameter evolutions and fire smoke patterns of the wall fire plume: Experimental and theoretical analysis

In the fire investigation field, fire smoke patterns are studied as one of the most important indicators for fire accident investigation and scene reconstruction. This paper studies the evolutions of wall fire plume characteristic parameter and the smoke patterns considering five oil pan sizes and three fuel types, with a wall fire plume experimental platform inside a large-scale laboratory. The mass loss rate (or heat release rate), flame height and near-wall centerline temperature are measured and analyzed quantitatively, and smoke patterns are extracted based on the image analysis. Results show that: (1) The heat release rate in the stable stage and the average heat release rate over the whole burning process are in linear relationship for various fuels. The relation of the near-wall temperature profile and dimensionless height is obtained, and the wall fire is divided into four regions. (2) Various fuels produce different smoke pattern characteristics due to the different composition and property. The wall fire plume smoke patterns considering the near-wall temperature profile can be divided into several conditions. In each condition, with the increase of oil pan size, the opening of fitting curve increases and the vertex height decreases. (3) The boundary of the smoke pattern increases with oil pan size. The non-dimensional wall fire plume smoke pattern model with the corresponding temperature profile is obtained. These can increase the data reserve of the wall fire plume smoke patterns produced by different fuels and enrich the experiment and numerical calculation basis of building fire.