Ignition and burning of the composite sample impacted by the Bunsen burner flame: A fully coupled simulation

Abstract

Experimental study and three-dimensional simulation of warming up, ignition, and subsequent burning out of the composite material impacted by the attached Bunsen burner flame is presented. The specimen is the fiberglass-reinforced composite with the epoxy resin binder. In the experiment, vertical specimen was located above the laminar diffusion flame, and transient variation of specimen mass and surface temperatures was recorded until the matrix polymer burned out. In the simulations, thermal decomposition of the composite was evaluated by the in-house pyrolysis model Pyropolis coupled with the general-purpose CFD solver, which simulated the flames generated by the burner and by the combustible volatiles. Formal kinetics of thermal decomposition of matrix polymer and the heat of combustion of volatiles have been derived from the microscale combustion calorimetry measurements. The simulation results include favorable comparisons of experimental and predicted dynamics of material degradation and flame behavior. Transient spatial distributions of surface temperature, burning rate, and heat fluxes (net, radiative and convective) are demonstrated. This study is the step towards developing the computational framework capable of replicating and predicting the outcome of standard fire tests UL94 and VBB.