During the beginning of the video, the vortex formed when the air was originally propelled from the mouth. The rest of the air then turns off the candle.
Notice the flow on the left side is lighter in color as it refracts less than the air on the right side. On the right side, the air is slightly hotter due to the passage on top of the hot candle surface.
This video is filmed on Chronos 1.4 Monochrome High-Speed Camera at 1000FPS at 1280x1024 resolution.
#chronoscameras #highspeed #camera #schlierenimaging #research #academics #science #fluid #chemistry #learnscience #stem #learn #educational #universities