Technology Unusual view

We happened to catch an unusual view while test running the motor on an Antares 20E. On that day the air humidity was only slightly under 100%. The negative pressure inside the propeller blade tip vortices caused condensation, revealing the otherwise invisible propeller wake. In our slow motion video, the propeller, which rotates at ca. 1400 rpm is slowed down by 1:10.
For a full-screen view in YouTube please use the following link: