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Gregory T. Linteris, Fumiaki Takahashi, Viswanath R. Katta, Valeri I. Babushok


The interaction of the gas-phase mechanisms of phosphorus flame retardants with the co-flow diffusion flame structure has been investigated computationally to complement the experimental research at NIST. Time-dependent axisymmetric computation was performed for cup-burner flames of methane with full gas-phase chemistry and transport to reveal the flame structure and inhibition processes. For the simulation of the effects of dimethyl methylphosphonate (DMMP) on the flames, a detailed chemical-kinetics model (77 species and 886 reactions) was constructed by combining the methane-oxygen combustion and phosphorus inhibition chemistry. A simple model for radiation from CH4, CO, CO2, H2O, and soot based on the optically thin-media assumption was incorporated into the energy equation. The calculated minimum extinguishing concentrations for a combination of DMMP added to the oxidizer or fuel flow and CO2 added to the oxidizer were in reasonable agreement with the measured values. There were striking differences in the effectiveness of DMMP, depending on where the retardant was introduced: the oxidizer or fuel. DMMP in the fuel stream (in comparison to the oxidizer) was practically ineffective in gas-phase inhibition of co-flow diffusion flames because of (1) a small stoichiometric mixture fraction (0.055 for methane), (2) the flame location on the oxidizer side of the dividing streamline, and (3) low concentrations of active phosphorus intermediate species (HOPO2, HOPO, PO2) in the flame stabilizing region.
Proceedings Title
Fire and Materials 2015
Conference Dates
February 2-4, 2015
Conference Location
San Francisco, CA


Fire retardants, flame inhibition, DMMP, dimethyl methylphosphonate, gas-phase fire retardants.


Linteris, G. , Takahashi, F. , Katta, V. and Babushok, V. (2015), SIMULATIONS OF GAS-PHASE INTERACTIONS OF PHOSPHORUS FLAME RETARDANTS WITH DIFFUSION FLAME STRUCTURE, Fire and Materials 2015, San Francisco, CA, [online], (Accessed May 19, 2024)


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Created February 2, 2015, Updated June 2, 2021