Flame Height of a Turbulent Diffusion Jet Flame with a Comparatively High Initial Discharging Velocity

Abstract

A series of experiments was carried out in order to investigate the visible flame height of a jet flame with a high initial discharging velocity where the fuel-release time and mass flow rate of fuel were varied. The values of non-dimensional heat release rate (Q^*) in present experiment were in the range of 10⁷ < Q^* < 10⁸. Even if the value of Q^* was larger than 10⁶, when the non-dimensional number (R_M) employed by Heskestad which implies the ratio of gas release momentum to the momentum made by a purely buoyant diffusion flame was less than 0.1, the flame height with a comparatively high initial discharging velocity increased with the heat release rate. In other words, whether flame height depends on the Q^*2/5 or not can be decided by the range of momentum ratio (R_M) regardless of the range of non-dimensional heat release rate (Q^*). This can be also decided by the fire Froude number employed by Delichatsios.