- Author
- Fernandez-Pello, A. C.
- Title
- Fire Propagation in Concurrent Flows. Final Progress Report. August 1, 1988-July 31, 1989.
- Coporate
- California Univ., Berkeley
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
- NIST GCR 89-569, December 1989, 25 p.
- Contract
- NGS-GRANT-60NANB7D0737
- Keywords
- air flow | flame length | flame spread | polymethyl methacrylate | pyrolysis
- Abstract
- A research program is being carried out to study the mechanisms controlling the spread of fire in a forced gas flow. Particular emphasis is given to the case when the gas flow is concurrent with the direction of fire spread. The research tasks completed during this reporting period include an experimental study of the effect on the flame spread rate of the turbulence intensity of a concurrent air flow, and a theoretical analysis of the effect of a prescribed gas velocity profile on the flame spread rate predictions. The results of the experiments show that for flames spreading over thick PMMA sheets, the flame spread process is significantly affected by the flow turbulence intensity. For a fixed flow velocity, the flame spread rate decreases as the turbulent intensity is increased. This appears to be mainly due to the shortening of the flame length. Schlieren images of the process indicate that the decrease of the flame length may be the result of the intense entrainment of cold air in the flame at the higher turbulent intensities. The results of the theoretical analysis indicate that the gas velocity profile influences strongly the flame spread rate predicitons.