Flow visualization over a 1/48-scale model of an <a href="https://en.wikipedia.org/wiki/F-18" class="extiw" title="en:F-18">F-18</a> aircraft inside a water tunnel at the Flow Visualization Facility from NASA's <a href="https://en.wikipedia.org/wiki/Dryden_Flight_Research_Center" class="extiw" title="en:Dryden Flight Research Center">Dryden Flight Research Center</a>.
Water flows over the aircraft model, and colored dyes, which are pumped through tubes with needle valves, flow back along the airframe. This photo highlights the appearance of <a href="https://en.wikipedia.org/wiki/Vortex" class="extiw" title="en:Vortex">vortices</a> over the <a href="https://en.wikipedia.org/wiki/Leading_edge_extension" class="extiw" title="en:Leading edge extension">leading-edge extensions</a>, as well as vortex burst further downstream, both typical of operations at high  <a href="https://en.wikipedia.org/wiki/Angle_of_attack" class="extiw" title="en:Angle of attack">angle of attack</a>.
Dryden Flight Research Center
1985-12-19
This image or video was catalogued by Armstrong Flight Research Center of the United States <a href="https://en.wikipedia.org/wiki/NASA" class="extiw" title="w:NASA">National Aeronautics and Space Administration</a> (NASA) under <b>Photo ID:</b> <a rel="nofollow" class="external text" href="https://images.nasa.gov/search?q=ECN-33298-47&amp;page=1&amp;media=image,video,audio&amp;yearStart=1920&amp;yearEnd=2023">ECN-33298-47</a>.