Research> FC sensors and actuators

Background

Whilst the theoretical and computational problems associated with modelling and controlling fluid flows are formidable, there still remains the challenge of how flow control solution are physically implemented in practical applications. In general, developing effective and efficient flow control actuators is more challenging than flow control sensors.

Flow control actuators may be divided in to two main classes:

• Momentum injection devices
  • devices powered by remote external air supply, e.g. air jet vortex generators, Circulation Control slots
  • electrically powered devices that use mechanical transduction to deliver local fluid momentum, e.g. Synthetic Jet Actuators (SJAs)
  • electrically powered devices that use direct electromagnetic transduction to deliver local fluid momentum, e.g. plasma actuators
• Variable geometry devices
  • micro flow disrupters for promotion of separation, e.g. micro tabs
  • micro flow mixers for delay of separation, e.g. vane vortex generators

Flow sensing for flow control applications is usually based on measurement of surface pressure and/or shear stress. A new type of sensor for non intrusive measurement of boundary layer profiles has been developed at Manchester by Phil Geoghegan based ultrasonic tomography.

Publications

Geoghegan, P., Crowther, W.J., and Wood, N.J., ‘Measurement of Boundary Layer Velocity Profiles by Ultrasonic Tomography for the Prediction of Flow Separation’, AIAA-2006-2805