Luqing Zhu - PhD Dissertation Presentation (FPE)
12:00 p.m. to 1:00 p.m.
Fire Protection Engineering Department
PhD Dissertation Presentation
Friday, August 29, 2025
12:00 p.m. – 2:00 pm
50 Prescott Street, Gateway II, Room 1226
Zoom link: https://wpi.zoom.us/j/6618555176
Luqing Zhu
Ph.D. Candidate in Fire Protection Engineering
Spot Ignition of Structural Fuels by Firebrand
Accumulations
Firebrand spotting is known as an important wildfire spread mechanism in both wildland and wildland-urban interface (WUI) fires over the past few decades. During this process, firebrands are lofted by plumes and transported downwind, where they may ignite receptive fuels (wildland fuels or structures) both near and far away from the flame front. When firebrands land nearby and accumulate into groups or piles, they can act as a more competent ignition source compared to single firebrands. The research presented in this dissertation focuses on characterizing airborne firebrands prior to the accumulation process and analyzing the capabilities of a group of firebrands to cause spot ignition of structural materials.
The first goal aims to bridge the diagnostic gap in measuring physical and thermal properties of flying firebrands generated from burning natural vegetation through an optical methodology. It is a crucial step toward predicting and modeling where firebrands will accumulate and in what concentrations, with important characteristics such as their size and temperature indicative of their ignition potential. The second goal focuses on studying how close firebrands need to be for acting as a group with enhanced heating ability. The importance of cooperative spot ignition effect due to proximity of two idealized firebrands was elucidated through experiments and numerical pyrolysis modeling. The last goal further focuses on analyzing the ignition ability of glowing firebrand groups (more than two) by considering a broader parameter space (wind, firebrand size, and accumulation density) with finer resolutions. Theoretical models were presented to account for the complex burning and spotting behaviors of firebrands within well-characterized accumulations.
Committee members:
Prof. James Urban (Advisor, Assistant Professor)
Worcester Polytechnic Institute
Prof. Albert Simeoni (Professor)
Worcester Polytechnic Institute
Prof. Michael Gollner (Associate Professor)
University of California, Berkeley
Prof. Rory Hadden (Professor)
The University of Edinburgh