Behavior of flames propagating over liquid films with metallic substrates

We have examined the propagation of a combustion wave over liquid fuel (n-butanol andn-undecane) films on substrates made form copper, aluminum molybdenum, and niobium under the conditions of a thermally thin layered system. It is shown that the flame edge is situated over the fluid surface, where the temperature of the layer system is sufficient to form a stoichiometric composition in the gas-phase mixture. The fuel film is evaporated at temperatures below the boiling point. The flame velocity does not depend (over a broad variation range) on the inclination angle of the substrate plane relative to the horizontal and is determined by the specific heat portion of the substrate in the substrate-fuel system. In the flame propagation mechanism, an important role is played by the heat transfer through the metallic substrate in the preignition zone. The heat recycling through the substrate results in an increase in the enthalpy in the gaseous phase due to the chemical component linked to the fuel vapor inflow from the film surface.