定断面積一様流中における流速が火花放電の放電路形状に及ぼす影響

抄録

This paper reports the effect of flow field on the deformation of spark discharge channels in terms of understanding of the spark ignition in the flow field. The automotive spark plug was installed in the constant-area flow (usually 25mm in diameter) with the orifice in the downstream to control the flow rate. The high pressure air was introduced through electro-magnetic valves from the upstream of the spark plug. The high voltages were applied using ignition coils and the deformation of the discharge channels in flow field were observed with high-speed camera. Due to the flow field, the spark discharge deformed in the flow direction and the foot of discharge channel was also changed. The total discharge time decreased with the increase in the flow velocity because of the high voltages due to the elongation of the discharge channel. The tip of discharge channel moved with time linearly and movement velocity of the channel were estimated. The movement velocity increased with the increase in the pressure and the trackability of the channel to the flow field was estimated.