Flame Spread over a Liquid Fuel Film in an Oxygen-Enriched Environment.

Flame spread over a thin film of various liquid fuels with an flash point below ambient temperature has been studied experimentally using thin copper and thick glass substrates in environments with different oxygen concentrations. It has been shown that with an increase in the oxygen concentration, the flame speed increases faster than the normal speed of the corresponding homogeneous stoichiometric mixture. When the proportion of oxygen in the mixture with nitrogen was changes from 0.21 (air) to 1, the flame speed changes from 0.02 to 2.4 m/s. At flame speeds above 0.3 m/s, the thermal thinness condition is not satisfied even for thin copper substrates. The flame speed ceases to depend on the substrate properties and the fuel layer thickness and becomes dependent only on the fuel properties. In this speed range, the flame speed increases linearly with increasing thermal effect of a unit volume of the stoichiometric mixture of fuel vapor with oxidizer and decreases with increasing difference between the temperature of formation of the stoichiometric composition under equilibrium conditions and the ambient temperature . [ABSTRACT FROM AUTHOR]