Home – Home – Jornals – Combustion, Explosion and Shock Waves 2023 number 1

Flame propagation over a thin film of various liquid fuels with an ignition point below the ambient temperature was experimentally studyied. The study was carried out on thin copper and thick glass substrates in media with different oxygen concentrations. It is 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 changes from 0.21 (air) to 1, the flame speed range is 0.02 ÷ 2.4 m/s. At flame propagation speeds above 0.3 m/s, the condition of thermal thinness is not satisfied even for thin copper substrates. The flame speed ceases to depend on the properties of the substrate and the fuel layer thickness and becomes dependent only on the properties of the fuel. In this speed range, the flame propagation speed increases linearly with an increase in the thermal effect of a unit volume of a stoichiometric mixture of fuel vapor with oxidizer and decreases with an increase in the difference between the temperature T_st at which the stoichiometric composition is formed under equilibrium conditions and the ambient temperature T₀.