Fire Protection Engineering Department Ph.D. Thesis Proposal - Pablo Pinto

Fire Protection Engineering Department

Ph.D. Thesis Proposal

Pablo Pinto

Thursday, February 12, 2026, 8:30 am – 11:00 am, 60P 1001

Zoom link:  https://wpi.zoom.us/j/94780692455

Horizontal Flame Spread Under Controlled Forced Flow

Committee:

James Urban, Ph.D. (Advisor and Assistant Professor; FPE WPI)

Maria Thomsen, Ph.D. (Assistant Professor, Engineering and Sciences, Universidad Adolfo Ibañez)
Ali Rangwala, Ph.D. (Professor, FPE and XPE WPI)

Ya-Ting Liao, Ph.D. (Associate Professor, Mechanical and Aerospace Engineering, Case Western Reserve University)

Abstract

Studying horizontal concurrent flame spread is essential in fire science and safety, as it plays a key role in real-world scenarios. This work presents an experimental investigation of horizontal concurrent flame spread in a bench-scale flow duct under steady and sinusoidally varying forced-flow conditions. Experiments are conducted on black-cast PMMA panels, with flame spread characterized by pyrolysis-front progression and heated-length measurements. Dimensional analysis based on the Richardson number is used to assess the relative roles of natural and forced convection; most cases fall in the mixed-convection regime, with brief transitions to natural convection. An empirical correlation incorporating the Richardson number is used to predict the flame spread rate by accounting for heat transfer to the heated zone. A tractable contour-based formulation is introduced to model the transient radiative heat transfer from the flame to the heated zone during flame spread. The transient radiative heat flux distribution is estimated using a side-facing radiometer and view-factor calculations between the flame, the radiometer, and points located at variable positions within the heated zone. Using this approach, radiative heat transfer under sinusoidally varying airflow is examined. Results show that incident flame radiation remains nearly constant, while the heated-zone size exhibits a strong transient response. This behavior is attributed to temporal variations in heated length. Two-dimensional spatial distributions of the incident radiative heat flux to the heated zone are also calculated and analyzed. To address this limitation, a methodology is presented to separate radiative and convective heat flux contributions from the flame to the fuel surface during flame spread. A second view-factor formulation is employed to estimate and subtract the radiative component, thereby isolating the convective contribution from the total heat flux. The flame spread rate is measured experimentally and independently estimated using the calculated radiative and convective heat fluxes, with strong agreement observed between the two approaches.