### 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} ΔH_{c}/ΔH_{v})^{2}, a pyrolysis or ignition time τ_{p}, and a transient pyrolysis parameter: λ = L/c ΔT_{p} = 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), ΔH_{c} is the heat of combustion and ΔH_{v} 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 language | English |
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Title of host publication | American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD |

Place of Publication | New York, NY, United States |

Publisher | Publ by ASME |

Pages | 21-28 |

Number of pages | 8 |

Volume | 223 |

ISBN (Print) | 0791810682 |

Publication status | Published - 1992 |

Externally published | Yes |

Event | Winter Annual Meeting of the American Society of Mechanical Engineers - Anaheim, CA, USA Duration: 1992 Nov 8 → 1992 Nov 13 |

### Other

Other | Winter Annual Meeting of the American Society of Mechanical Engineers |
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City | Anaheim, CA, USA |

Period | 92/11/8 → 92/11/13 |

### Fingerprint

### ASJC Scopus subject areas

- Fluid Flow and Transfer Processes
- Mechanical Engineering

### Cite this

*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.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*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.

}

TY - GEN

T1 - Similarity solutions and applications to turbulent upward flame spread on non-charring materials

AU - Delichatsios, Michael A.

AU - Delichatsios, Mary

AU - Chen, Y.

AU - Hasemi, Yuji

PY - 1992

Y1 - 1992

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=0026995306&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0026995306&partnerID=8YFLogxK

M3 - Conference contribution

AN - SCOPUS:0026995306

SN - 0791810682

VL - 223

SP - 21

EP - 28

BT - American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD

PB - Publ by ASME

CY - New York, NY, United States

ER -