Development of an innovative model to simulate the impact of forest fires

Name: Bianca

Surname: Tenti

Tutor (surname): Enrico Ferrero

website: https://upobook.uniupo.it/enrico.ferrero

One of the most important consequences of wildfires is the worsening of air quality even far from the fire itself because of transport by the wind. During wildfire emergencies, a proper description of pollutants dispersion within the atmosphere is important to promptly take precautionary measures to contain the damage.

Correct modeling of the "plume rise" phenomenon is fundamental for a proper description of the pollutants’ dispersion. In particular, the maximum height the plume will reach before releasing most of the smoke burden into the wider atmosphere affects the transport of fire emissions, since wind speed at different altitudes may be quite different. One of the most important parts of plume rise modeling is the entrainment phenomenon: during the rise, momentum is transferred to the surrounding environment and colder air coming from outside is incorporated inside the plume, decreasing its temperature and velocity, and increasing its size. Entrainment modeling results in high computational cost because both particles inside and outside the plume must be considered. For this reason, the plume will be divided into cubic cells for each of which two scalar quantities are computed: the temperature difference between the plume cell and the external environment and the vertical speed. These two scalar quantities are transported using transport equations and updated after the displacement. This method allows us to emit no more particles than those inside the plume because the information about temperature and speed is transported as scalar quantities. The validation of the model will be carried out at Simularia, the partner company of this project.

The achievement of the objectives of the research project will allow in-depth and realistic modeling of the plume rise, resulting in a correct evaluation of the pollutants’ dispersion within the atmosphere during a wildfire to provide qualitative and quantitative results in a short time.