Accession Number : ADA330601

Title :   Application of Micro Electro-Mechanical Sensors and Activators in the Investigation of Supersonic Jet Screech.

Descriptive Note : Final rept., 1 Sep 95-30 Jul 97

Corporate Author : ILLINOIS INST OF TECH CHICAGO FLUID DYNAMICS RESEARCH CENTER

Personal Author(s) : Nagib, Hassan ; Papp, Joe ; Naguib, Ahmed

PDF Url : ADA330601

Report Date : 30 JUL 1997

Pagination or Media Count : 14

Abstract : An investigation aimed at examining the usability of MEMS based actuators for controlling supersonic jet screech has been conducted. First, documentation of the screech phenomenon in the newly constructed high speed jet facility (HSJF) at IIT has been completed. Results from microphone measurements complemented with earlier shadowgraph and schlieren visualization have shown that the screech characteristics in the HSJF conforms with that published in the literature. Second, detailed investigation of the first generation MEMS actuators showed that the actuators could not operate for speeds higher than 70 m/s while maintaining contact with the jet shear layer. This was attributed to the bending moment acting on the actuator due to flow loading on the overhanging head portion of the device. This observation was confirmed utilizing a special headless actuator design. The outcome of the tests of the first generation devices guided the development of a second generation of actuators. Those actuators, which are also described within this report, are currently being evaluated.

Descriptors :   *MICROELECTRONICS, *SUPERSONIC FLOW, *MICROMECHANICS, *JET FLOW, AERODYNAMIC STABILITY, TURBULENCE, FLOW VISUALIZATION, ELECTROMECHANICAL DEVICES, ACTUATORS, MULTISENSORS, SUPERSONIC NOZZLES, SHEAR FLOW, SPARK SHADOWGRAPH PHOTOGRAPHY, BENDING MOMENTS, ACOUSTIC RESONANCE.

Subject Categories : Electrical and Electronic Equipment
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE