Ignition phase transition of a polymer: Convective exposure

✍ Scribed by Professor P. Durbetaki; T. X. Phuoc

• Book ID: 102962668
• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 654 KB
• Volume: 25
• Category: Article
• ISSN: 0029-5981
• DOI: 10.1002/nme.1620250208

✦ Synopsis

The ignition of a semi-infinite solid polymer under convective exposure is investigated. A quasi-steady approximation is used for the gas phase and the transient effect is accounted for in the solid phase only. Both surface and gas phase chemical reactions are included simultaneously. The ignition mechanism is studied in terms of the concurrent heat transfer, mass transfer and chemical processes at the surface as well as in the gas phase. The gas phase governing equations are integrated independently from the solid phase energy equation using the Adams-Moulton subroutine. Corrections to the iterative procedure are carried out by establishing a set of perturbation equations and using the Newton-Raphson and least-squares methods. The results indicate that ignition occurs in the heterogeneous mode within a narrow range of low flow velocities and high temperatures. An ignition phase transition point exists, and within a wide range of high flow velocities, ignition switches to the homogeneous mode.