Fire Protection Engineering Department Ph.D. Thesis Defense - Pablo E. Pinto
9:00 a.m. to 12:00 p.m.
Fire Protection Engineering Department
Ph.D. Thesis Defense
Heat Transfer Mechanisms During Horizontal-concurrent
Flame Spread Under Transient and Steady Forced Flow
Monday, March 09, 2026
9:00 am – 12:00 pm
FPE Classroom/50 Prescott St
Zoom link: https://wpi.zoom.us/j/91370243030
Committee:
James Urban, PhD - Assistant Professor, WPI Fire Protection. Engineering (Advisor)
Maria Thomsen, PhD - Assistant Professor, Universidad Adolfo Ibañez, Engineering and Sciences
Ali Rangwala, PhD - Professor, WPI Fire Protection Engineering, Prog. Dir. Explosion Protection Engineering
Ya-Ting Liao, PhD - Associate Professor - Case Western Reserve University, Mechanical & Aerospace Engineering
Abstract
Understanding the heat transfer mechanisms that govern the interaction between the flame and the solid fuel surface is essential for predicting and modeling flame spread. The relative contribution of these mechanisms depends strongly on the imposed airflow and its interaction with buoyancy. Horizontal concurrent flame spread is experimentally investigated in a bench-scale flow duct under both steady and non-steady airflow conditions. The non-steady airflow is prescribed through a controlled sinusoidal profile defined by a baseline velocity, amplitude, and frequency. Experiments are conducted on black-cast thermally thin polymethyl methacrylate (PMMA) panels, and flame spread is characterized through the temporal evolution of the flame geometry. Radiative heat transfer to the heated zone is estimated using an analytical radiation view factor analysis and experimental heat flux measurements. Convective heat transfer is calculated from the difference between total and radiative heat fluxes, and a local Nusselt-number correlation is used to determine the convective heat-transfer coefficient under steady airflow conditions. The thermal response of the fuel sample during the experiments is also quantified. Under non-steady conditions, the imposed flow exerted a stronger influence on the gas phase phenomena (i.e., flame extension over the sample) than on the solid phase (resulting flame spread), with the solid phase exhibiting a pronounced response only at maximum flow amplitudes. However, even with a clear transient response in the flame spread rate, faster average flame spread rates were achieved under non-steady flow. The spatially resolved radiation and convection analysis allow for the relative contribution of each mechanism to flame spread to be quantified.