Posters + Videos
Check out our work in other forms of media! Be sure to visit our YouTube Channel, too!
Scaly Flows
A thin sheet of water flowing over surfaces with alternating hydrophilic (water-attracting) and hydrophobic (water-repelling) bands introduces "scales" in the flow, leading to the formation of a pinecone-like structure.
Presented at the 2015 annual American Physical Society's Division of Fluid Dynamics meeting in the Gallery of Fluid Motion.
Active Flow Control (AFC)
Sweeping jet actuators, which emit a continuous jet that swings from one side of the outlet nozzle to the other, are a promising type of active flow control devices for aircraft tails and rudders.
The size of aircraft vertical tails are usually based on the needs of emergency situations, such as engine failure at low airspeeds. As a result, they are oversized for normal operating conditions. Sweeping jet actuators can be employed to delay flow separation over the tails and increase side force generation, thus allowing aircraft to be built with smaller tails that still perform as necessary under emergency conditions.
This video illustrates flow in a sweeping jet actuator as the incoming air flow is started up. Flow is left to right.
Liquid Bridges
Our work with hydrophobic (water repelling) and hydrophilic (water attracting) surfaces extends to liquid bridges. Liquid bridges occur when water rivulets flowing over horizontal or partially inclined hydrophobic plates are lifted off the surface. The rivulets arch through the air as gravity then pulls them back down to the surface.
This video was entered in the 2015 Gallery of Fluid Motion at the annual American Physical Society's Division of Fluid Dynamics meeting, held in Boston, MA.
Music: Ludwig van Beethoven, Symphony No. 5 (Allegro) performed by Lambis Vassailidis. From MusOpen. Creative Commons license.
Imaging Techniques for AFC
The 3-dimensional flow over an aircraft's vertical tail and rudder is obtained using defocusing digital particle image velocimetry (DDPIV).
Flow over a non-modified aircraft tail. This flow serves as the baseline case for comparison with flow when AFC is applied.
Sweeping jet actuators are incorporated on the aircraft tail in order to delay flow separation.