Micro-actuator Development Facility

Micro-actuators developed for active control of high-speed flows are characterized in the Micro-Actuator Development Laboratory. Due to the scale of these actuators and the unsteady nature of the high-speed flows produced by them, specialized techniques are required for their characterization. Experiments conducted in this laboratory typically include measuring acoustic data, unsteady pressure fluctuations, and velocity field measurements using Particle Image Velocimetry (PIV). High magnification flowfield images of the actuators are also acquired using highly sensitive schlieren systems, such as the Laser-Based Micro-Schlieren system. The detailed analyses performed in this laboratory have led to the successful implementation and demonstration of the capabilities of these actuators in high-speed flow facilities, such as the STOVL impinging jet facility and the supersonic wind tunnel.

Laser-Based Micro-Schlieren system

This facility uses a specialized micro-Schlieren system that combines the typical components of a lens-based Schlieren system with a unique light source. An Nd:YAG PIV laser is focused to a point inside of a small argon atmosphere, where a plasma spark is produced. The high intensity, short duration (< 10 ns) light emitted from this plasma sets the exposure time and effectively freezes high-speed, micro-scale flows.

Operational / Test Capabilities

  • High-pressure supply lines up to 120 psig
  • Run duration virtually unlimited
  • High-Speed LEDs with variable duty cycle up to 100% and frequencies up to 100 kHz
  • High-Speed cameras with frequency ranges up to 600,000 fps
  • High-Intensity Nd:YAG Lasers with 100 - 200 mJ/pulse

Diagnostics and Test Hardware

  • Steady and Unsteady pressure and acoustic measurements
  • Micro-Schlieren flow visualizations with phase-conditioning capabilities
  • Labview-based data acquisition with high-speed, simultaneous data acquisition cards
  • Signal conditioning including amplifiers and programmable filters

Research Activities

  • Microactuator design and characterization
  • Integration of smart materials into microactuators
  • Ultra-high frequency microactuator development
  • Research supported by AFOSR, AFRL, NAVSEA NEEC