Observations of the Propagating Flames in Vortex Rings Using an Image Intensifier

Using a high-speed video camera with an image intensifier, observations have been made on the propagating flames in the vertex rings. From their intensified images, variations of the flame speed and the flame diameter along the vortex axis have been determined. Results show that there are four types of flame propagation, (1) steady flame propagation, (2) periodic flame propagation, (3) unsteady flame propagation, and (4) random flame propagation. The steady flame propagation occurs for the maximum tangential velocity Vθmax>7 m/s (Re