旋回乱流散火炎に関する研究 : バーナ直管部の長さが火炎の長さにおよぼす影響

抄録

The height of the diffusion flames issued vertically from a cylindrical swirl burner in free air extends in accordance with the decrease of swirl intensity at the burner exit. In the present experiment, straight tube extensions were equipped to the burner exit and the height of the swirling diffusion flames was measured for the length of the tube. The swirl intensity at the tube exit, which was given by the measurement of the flame height, decreased exponentially with an increase in tube length as a parameter of the swirl intensity at the tube entrance, and was much different from the values calculated using the well-known relation of swirl flow in a straight tube. In the case of a swirling jet with burning flow, the decay of swirl intensity near the tube exit is considered to be strongly influenced by the condition of decay or diffusion of the swirling jet in free air.