Plasmas are a soup of charged particles in an electric field, and are normally found in stars and lightning bolts. With the use of high voltage equipment, very small plasmas can be used to manipulate fluid flows. In recent years, the development of devices known as plasma actuators has advanced the promise of controlling flows in new ways that increase lift, reduce drag, and improve aerodynamic efficiencies -- advances that may lead to safer, more efficient and more quiet land and air vehicles in the near future.
Unlike other flow control devices, plasma actuator geometries can be easily modified. Enter the serpentine shape, courtesy of the Applied Physics Research Group (APRG), a University of Florida research team in Gainesville that has been developing this and other types of novel plasma actuators for several years. The serpentine's sinuous, ribbon-like curves appear to impart greater levels of versatility than traditional geometries used in plasma flow control devices.
The team validated the complex, three-dimensional flow structures induced by their serpentine plasma actuators by comparing numerical results with recent physical experiments in non-moving air. They then simulated the effects of the actuators in a non-turbulent boundary layer and over a small aircraft wing. Further tests are needed, but early results suggest serpentine flow wrangling may improve transportation efficiencies.