Similarity solutions and applications to turbulent upward flame spread on non-charring materials

Michael A. Delichatsios, Mary Delichatsios, Y. Chen, Yuji Hasemi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

Turbulent upward flame spread on non-charring materials (for pyrolysis lengths less than 1.8 m) is shown to be directly predicted by using measurable flammability parameters. The controlling parameters are: a combustion related length scale which is proportional to (dq″net ΔHc/ΔHv)2, a pyrolysis or ignition time τp, and a transient pyrolysis parameter: λ = L/c ΔTp = ratio of the latent heat to the sensible heat of the pyrolysis temperature of the material. In the length scale parameter, dq″net is the total net heat flux from the flames to the wall (i.e. total heat flux minus reradiation losses), ΔHc is the heat of combustion and ΔHv is an effective heat of gasification for the material. The pyrolysis or ignition time depends (for thermally thick conditions) on the material thermal inertia, the pyrolysis temperature and the total heat flux from the flames to the wall, dq″fw. The controlling parameters were developed by using a numerical simulation, developed earlier, and new exact similarity solutions which complement existing similarity solutions. The predictions of the analysis are validated by comparison with upward flame spread experiments on PMMA. The present results are directly applicable for pyrolysis lengths less than 1.8 m over which experiments in practical materials show that the total (radiative and convective) heat flux to the wall from the flames is constant and nearly uniform over the flame length. As the pyrolysis length increases (>approx. 1.8 m), radiation dominates and a different total wall heat flux distribution applies.

Original languageEnglish
Title of host publicationAmerican Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD
Place of PublicationNew York, NY, United States
PublisherPubl by ASME
Pages21-28
Number of pages8
Volume223
ISBN (Print)0791810682
Publication statusPublished - 1992
Externally publishedYes
EventWinter Annual Meeting of the American Society of Mechanical Engineers - Anaheim, CA, USA
Duration: 1992 Nov 81992 Nov 13

Other

OtherWinter Annual Meeting of the American Society of Mechanical Engineers
CityAnaheim, CA, USA
Period92/11/892/11/13

Fingerprint

Pyrolysis
Heat flux
Ignition
Enthalpy
Latent heat
Flammability
Polymethyl Methacrylate
Gasification
Experiments
Radiation
Temperature
Hot Temperature
Computer simulation

ASJC Scopus subject areas

  • Fluid Flow and Transfer Processes
  • Mechanical Engineering

Cite this

Delichatsios, M. A., Delichatsios, M., Chen, Y., & Hasemi, Y. (1992). Similarity solutions and applications to turbulent upward flame spread on non-charring materials. In American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD (Vol. 223, pp. 21-28). New York, NY, United States: Publ by ASME.

Similarity solutions and applications to turbulent upward flame spread on non-charring materials. / Delichatsios, Michael A.; Delichatsios, Mary; Chen, Y.; Hasemi, Yuji.

American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD. Vol. 223 New York, NY, United States : Publ by ASME, 1992. p. 21-28.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Delichatsios, MA, Delichatsios, M, Chen, Y & Hasemi, Y 1992, Similarity solutions and applications to turbulent upward flame spread on non-charring materials. in American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD. vol. 223, Publ by ASME, New York, NY, United States, pp. 21-28, Winter Annual Meeting of the American Society of Mechanical Engineers, Anaheim, CA, USA, 92/11/8.
Delichatsios MA, Delichatsios M, Chen Y, Hasemi Y. Similarity solutions and applications to turbulent upward flame spread on non-charring materials. In American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD. Vol. 223. New York, NY, United States: Publ by ASME. 1992. p. 21-28
Delichatsios, Michael A. ; Delichatsios, Mary ; Chen, Y. ; Hasemi, Yuji. / Similarity solutions and applications to turbulent upward flame spread on non-charring materials. American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD. Vol. 223 New York, NY, United States : Publ by ASME, 1992. pp. 21-28
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