2018 Volume 49 Issue 6 Pages 1150-1155
Schlieren photography is well known as a visualization method of flame propagation. However, in case of spark ignition, the shape or size of initial flame kernel cannot be distinguished due to density variation caused by the plasma or preheating zone. In this paper, the authors attempted to visualize both the discharge channel and the initial flame kernel formation using both a normal high-speed camera and an infrared high-speed camera. In a constant volume combustion chamber, simultaneous visualizations using a CO band filtered infrared and a normal high-speed camera were conducted. A normal high-speed camera was used for schlieren photography and direct imaging of spark channel. As a result, the possibility to distinguish the initial flame kernel from the spark plasma was suggested by using an infrared high-speed camera.
