TY - JOUR

T1 - Experimental and Numerical Study of Downward Flame Spread over Glass-Fiber-Reinforced Epoxy Resin

AU - Korobeinichev, Oleg

AU - Karpov, Alexander

AU - Shaklein, Artem

AU - Paletsky, Alexander

AU - Chernov, Anatoliy

AU - Trubachev, Stanislav

AU - Glaznev, Roman

AU - Shmakov, Andrey

AU - Barbot’ko, Sergey

N1 - Funding Information: Funding: This research was funded by the Russian Science Foundation, grant number 20-19-00295. Publisher Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2022/3/1

Y1 - 2022/3/1

N2 - For the first time, a comprehensive study of downward flame spread over glass-fiber-reinforced epoxy resin (GFRER) slabs in oxidizer flow has been carried out experimentally and numerically. Microthermocouples were used to measure the temperature profiles on the solid fuel’s surface and in the flame, and a video camera was used to measure the rate of flame spread (ROS). The ROS was found to be linearly dependent on the oxygen concentration, to be inversely proportional to the slab thickness and not to depend on the direction of the flame spread over the slab. The absence of the influence of the forced oxidizing flow velocity and the weak influence of the GFRER pyrolysis kinetics on the ROS were observed. For the first time, a numerical model of flame spread over reinforced material with thermal conductivity anisotropy was developed on the basis of a coupled ‘gas–solid’ heat and mass transfer model, using modifications of the OpenFOAM open-source code. The sensitivity analysis of the model showed that the thermal conductivity in the normal direction to the GFRER surface had a much greater effect on the ROS than the thermal conductivity along the direction of flame propagation. The numerical results show good agreement with the experimental data on the dependences of the ROS on oxygen concentration, slab thickness and the N2/O2 mixture flow velocity, as well as temperature distributions on the fuel surface, the maximum flame temperatures and the flame zone length.

AB - For the first time, a comprehensive study of downward flame spread over glass-fiber-reinforced epoxy resin (GFRER) slabs in oxidizer flow has been carried out experimentally and numerically. Microthermocouples were used to measure the temperature profiles on the solid fuel’s surface and in the flame, and a video camera was used to measure the rate of flame spread (ROS). The ROS was found to be linearly dependent on the oxygen concentration, to be inversely proportional to the slab thickness and not to depend on the direction of the flame spread over the slab. The absence of the influence of the forced oxidizing flow velocity and the weak influence of the GFRER pyrolysis kinetics on the ROS were observed. For the first time, a numerical model of flame spread over reinforced material with thermal conductivity anisotropy was developed on the basis of a coupled ‘gas–solid’ heat and mass transfer model, using modifications of the OpenFOAM open-source code. The sensitivity analysis of the model showed that the thermal conductivity in the normal direction to the GFRER surface had a much greater effect on the ROS than the thermal conductivity along the direction of flame propagation. The numerical results show good agreement with the experimental data on the dependences of the ROS on oxygen concentration, slab thickness and the N2/O2 mixture flow velocity, as well as temperature distributions on the fuel surface, the maximum flame temperatures and the flame zone length.

KW - Combustion

KW - Coupled model

KW - Flame spread

KW - Glass fiber reinforcement

KW - Numerical modeling

KW - Opposed flow

KW - Polymer composites

KW - Pyrolysis

KW - Temperature measurement

KW - Thermal conductivity

UR - http://www.scopus.com/inward/record.url?scp=85125566974&partnerID=8YFLogxK

U2 - 10.3390/polym14050911

DO - 10.3390/polym14050911

M3 - Article

C2 - 35267734

AN - SCOPUS:85125566974

VL - 14

JO - Polymers

JF - Polymers

SN - 2073-4360

IS - 5

M1 - 911

ER -