Simulation Study and Proper Orthogonal Decomposition Analysis of Buoyant Flame Dynamics and Heat Transfer of Wind-Aided Fires Spreading on Sloped Terrain
The wind and slope are deemed to be the determinant factors driving the extreme or erratic spread behavior of wildfire, which, however, has not been fully investigated, especially to elaborate the mechanism of fire spread associated with heat transfer and fluid dynamics. A systematic study is theref...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-03-01
|
| Series: | Fire |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2571-6255/8/4/139 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | The wind and slope are deemed to be the determinant factors driving the extreme or erratic spread behavior of wildfire, which, however, has not been fully investigated, especially to elaborate the mechanism of fire spread associated with heat transfer and fluid dynamics. A systematic study is therefore carried out based on a physical-based simulation and proper orthogonal decomposition (POD) analysis. Results show that compared to the wind, the slope plays a more profound effect on the fire structure; with the increase in slope, the fire line undergoes a transition from a W-shape to the U- and pointed V-shape, accompanied by stripe burning zones, indicating a faster spread but incomplete combustion. The wind effect is distinguished by mainly inducing a turbulent backflow ahead of the fire front, while the slope effect promotes convective heating via the enhanced slant fire plume. Different mechanisms are also identified for the heat transfer ahead of the fire line, i.e., the radiative heat is affected by the combined effects of the flame length and view angle, and in contrast, the convective part of the heating flux is dominated by the action of the flame attachment, which is demonstrated to play a crucial role for the fire spread acceleration at higher slopes (>20°). The POD analysis shows the distinct pattern of flame pulsating for the respective wind and slope effects, which sheds light on modeling the unsteady features of fire spreading and reconfirms the necessity of considering the different effects of these two environmental factors. |
|---|---|
| ISSN: | 2571-6255 |