Accession Number : ADA330573

Title :   Active Control of Supersonic Jet Screech Using MEMS.

Descriptive Note : Final technical rept. 15 Jun 96-14 Jun 97,

Corporate Author : ILLINOIS INST OF TECH CHICAGO DEPT OF MECHANICS MECHANICAL AND AEROSPACE ENGI NEERING

Personal Author(s) : Naguib, Ahmed ; Nagib, Hassan ; Alnajjar, Emad ; Christophorou, C. ; Najafi, Khalil

PDF Url : ADA330573

Report Date : SEP 1997

Pagination or Media Count : 8

Abstract : The primary objective of this research is to investigate the usability of mechanical actuators, manufactured using MEMS technology, in the control of high-speed, compressible free shear flows. Appropriate development of MEMS-based actuators for flow control applications must address two issues: (1) the ability of the micron-size amplitude and forces of the MEMS devices to affect larger-scale flows with orders of magnitude higher energy, and (2) the survivability of the fairly fragile actuators when they are exposed to the flow in which they are embedded. Therefore, the current investigation is aimed at testing MEMS actuators for the purpose of controlling supersonic jet screech. For this application, the high-speed, highly-unsteady nature of the flow during screech provides a reasonably harsh environment for testing the survivability of the actuators. Furthermore, the shear layer surrounding the jet at its exit is known to be highly unstable to minute disturbances in the vicinity of the lip of the jet, and hence it is anticipated that the micron-size disturbances introduced by the MEMS actuators will be amplified through the shear layer instability mechanisms to produce large scale effects on the jet itself.

Descriptors :   *SHEAR PROPERTIES, *MECHANICAL PROPERTIES, *COMPRESSIBLE FLOW, *ACTUATORS, CONTROL, LAYERS, SCALING FACTOR, AMPLITUDE, INSTABILITY.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE