Cancelling damping induced by drag in synthetic jets using performance enhancements

A synthetic jet generator comprising:

• a chamber defined by a housing, wherein an aperture is disposed in the housing, and wherein a fluid is disposed in the chamber;
• a piston operably disposed to repeatedly compress the fluid in the chamber, wherein during compression strokes the piston forces a jet of the fluid to flow from the aperture;
• a motor connected to the piston and configured to drive the piston;
• a drive circuit in communication with the motor and configured to control operation of the piston by generating a drive signal communicated to the motor;
• a sensor operably connected to one of the piston and the housing, and configured to take a measurement of a motion of the piston;
• a feedback circuit connected to the sensor and to the drive circuit, and configured to incorporate a feedback signal into the drive signal, wherein the feedback signal includes the measurement of the motion of the piston at a resonance frequency of the chamber;
• wherein the feedback circuit is further configured to add a component to the feedback signal, the component comprising a force calculated to cancel damping effects of a drag on the fluid flowing from the aperture;
• wherein the feedback circuit includes a rate estimator and a gain, wherein the rate estimator is a first circuit that is configured to sum the motion of the piston into the feedback signal, and wherein the gain comprises a second circuit that is configured to increase an amplitude of the feedback signal;
• and
• wherein the feedback circuit, in being configured to add a component to the feedback signal, is further configured to increase a first velocity of the jet relative to a second velocity of the jet that occurs when the chamber is at resonance without inclusion of the feedback signal.