An experimental evaluation of an entrainment flame-propagation model

✍ Scribed by E.G. Groff

• Book ID: 103039663
• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 747 KB
• Volume: 67
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(87)90148-9

✦ Synopsis

Experimental burning-velocity and propagation-velocity data are presented for laminar and turbulent flames ignited in a constant-volume vessel. Burning velocities were obtained using a double-kernel technique whereby the expansion component of the propagation velocity is canceled by propagating two flames toward one another. Propagation velocities were obtained from freely propagating flames. The turbulent flow field was the same in both experiments. High-speed schlieren photography was used to determine flame velocities.

The burning-velocity data are used as one input parameter to a two-parameter entrainment flame-propagation model published in the literature. The model is then fit to the flame-radius and propagation-velocity data to determine the other parameter, a characteristic reaction time. It is shown that the model underestimates experimentally observed flame acceleration unless burning velocity is reduced at small flame radii with an empirical term which is a function of flame radius and thickness. With the empirical term the entrainment model does a reasonable job of predicting flame-propagation rates for the flames examined.