A Pulsed Micro-Jet Actuator

About

Adaptive Control of Air Flow Using a Piezoelectric Controlled Pulsed Micro-jet Actuator Controlling the flow of air over a surface, such as an airplane wing or rocket body, improves manoeuvrability and reduces the occurrence of stall. Traditionally, structures and systems used to control air flow include mechanical and/or servo-hydraulic actuators that rotate an aileron or rotor blade to mitigate the loss of lift from separated flow. More recently, active flow control systems in the form of bench-top demonstrations have been successful alternatives to controlling air flow; however, these applications are limited in their effectiveness because their designs are unable to effectively handle the performance variations that occur across different aircraft structures and operating conditions. Namely, these active flow systems are limited to a narrow frequency band and subsonic flow applications. A solution to the limitations mentioned above involves the design of a piezoelectric microjet actuator that integrates smart materials into a microjet to produce broadband pulsed flow with high actuation forces that can be adjusted in real-time to better prevent stall scenarios and reduce noise on a case-by-case and as-needed basis for a wide variety of aircraft types. Importantly, this actuator operates effectively under subsonic and supersonic conditions, and the adaptive structures inherent in the actuator’s design reduce the parasitic load on the jet engine to ½% or less of the main flow field. The result of this design is a lighter, smaller, more efficient, and less complex air flow actuator that improves aircraft agility and efficiency while reducing noise. Applications Aerospace. Automotive. Military. Improves agility and efficiency, reduces noise. Unique Advantages Can adjust air pulsations in real-time to prevent/reduce stall scenarios. Has a built-in feedback loop that enables air to be pulsed at different frequencies. Produces high actuation forces (kN) and broad bandwidth (quasi-static to approximately 10kHz) at small displacements. Capable of pulsing subsonic and supersonic flows. Actuator is less complex in design and smaller in size and weight. Can work in compact aerodynamic structures, such as rotor blades and rockets Status Provisional patent filed March 23, 2010. A working prototype has been developed in the lab. Current Work Underway Design and characterize the performance attributes of the actuator. Perform design iterations based on the first round of data. Integrate the actuators into aircraft control surfaces and wind tunnel experiments to quantify flow control performance.