Eddy Diffusions of a Fuel Gas from a Cylindrical Fuel Burner

Abstract

It is easy to determine the mechanism of time average eddy diffusion of fuel gas in a flame. But it is very difficult to determine the instantaneous movements of fuel gas in the flame. In the experiment described in this paper the fuel jet was ignited at various positions in the fuel jet by electric sparks, and the spreading of the flame was observed. Ignition probability was measured at various positions of the fuel jet, being determined by the mixture ratio and mean velocity of fuel jet and the velocity of secondary air. It seems that the ignition probability chiefly depends upon the fluctuation of the fuel concentration. It was found that, for an ignition for obtaining a steady flame, a spark must be provided immediately behind the burner tube wall.