Characterization of a Novel Inclinable Wind Tunnel for the Fundamental Study of Wildfire Combustion

As the frequency and magnitude of wildfires grow worldwide, it is becoming increasingly important to understand the dynamics behind how these fires grow and spread. Wildfire spread is complex and affected by numerous variables. Two of these– cross-flow wind speed and ground slope– have a significant impact on the physical and chemical processes that occur during a burn. A novel inclinable wind tunnel facility (the WindCline) was constructed to study the coupling between the inertial cross-flow and buoyancy vectors in a controlled, combusting flow. The facility allows both the angle and ratio between the two vectors to be modified. The WindCline can operate at wind speeds up to 20 m/s with a freestream turbulence intensity less than 1% and is inclinable from -13 to +15 degrees. The 0.35 m wide by 0.85 m long test-section is highly modular to allow for combustion experiments with both solid fuel arrays and gaseous burners in flexible arrangements. The suite of measurement systems used to investigate both fluid dynamic and combustion processes in these flows includes high-speed particle image velocimetry, dual frequency comb laser spectroscopy, and particulate matter emissions sensors. A detailed characterization of the WindCline facility will be presented in addition to preliminary results for solid fuel combustion arrays of wooden pegs.