Dynamics of Buoyant Plumes in Stratified Atmospheric Boundary Layer

Turbulent buoyant plumes are prevalent in nature and could arise from both natural and human-induced geophysical events. Wildfires and prescribed fires are major examples of buoyant plumes that are released in the atmospheric boundary layer. During fires, the buoyancy forces from the heat released into the surrounding is responsible for initiating and sustaining the turbulent plumes. A fundamental understanding of the mechanism governing the development, rise, and dispersion of buoyant plumes resulting from intense heating during prescribed fires at different atmospheric stability conditions is essential to guide smoke management plans. This study investigates the effects of the atmospheric stratification and boundary layer wind and temperature profiles on the plume rise and dispersion mechanism for a pool fire and line fire. Through computational fluid dynamics involving large-eddy simulations, the study investigates the plume dynamics under stable, unstable, and neutral atmospheric conditions.