Flame Behavior and Thermal Propertoifes a Jet Flame with a HighInitial Discharging Velocity

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In order to investigate flame behavior and thermal properties of the jet flame with comparatively high initial velocity, a series of experiments was carried out. The jet flame was made vertically in the present experiment, and to investigate the influence of the flame formation direction on the flame behavior and thermal properties, present experimental datum were compared with the datum of the flame length and temperature of hydrogen jet flame in reference. The fuel releasing time and the mass flow rate of fuel were varied as experimental conditions. At least one second is necessary to reach a quasi steady state for the height of the jet flame with comparatively high initial velocity, and at least three seconds is necessary for the temperature around the jet flame. The range that the flame height (flame formation direction: vertical) and/or flame length (flame formation direction: horizontal) depend on the Q*2/5 and the range that the flame height and/or flame length don't deped the heat rlease rate can be divided by the range of RM which implies the ratio of the gas release momentum to the momentum generated by a purely buoyant diffusion flame, regardless of the range of Q*. The temperature along the central axis of the jet flame maintains similarity with the change of the heat release rate. The starting point of the temperature decrease was moved further position from the fire source which was the outlet of the fuel releasing nozzle. But once the temperature decrease starts, the temperature decreased more rapid than McCaffrey's relation. The empirical formulae on the temperature along the central axis of the jet flame were developed which can predict regardless of the formation direction of the jet flame.