Vortex ring generation device

A vortex ring generation device, comprising:

• a casing having a gas passage and a discharge port;
• and
• an extrusion mechanism configured to extrude gas in the gas passage through the discharge port such that the gas in a vortex ring shape is discharged from the discharge port,
• the extrusion mechanism including at least one vibration plate, each vibration plate including an actuator configured to change a volume of the gas passage and to extrude the gas of the gas passage when the volume is reduced, each vibration plate being fixed to the casing, each actuator moving the respective vibration plate in a direction perpendicular to the discharge port,
• the casing being installed in a wall of a target space into which the gas in the vortex ring shape is discharged,
• when V (m3), which is a volume of the gas extruded through the discharge port when the gas passage is reduced, represents an extrusion volume, D (m) represents a diameter of the discharge port, U (m/s) represents a discharge velocity, and L (m) represents a length of an equivalent cylinder having the extrusion volume V and the diameter D,
• 0.045≤D≤0.060,
• 0.15≤L≤0.35, and
• 3≤U≤5.