Mitigation of Aero-Optic Distortions by Active Flow Control

Award Information
Agency:
Department of Defense
Amount:
$99,955.00
Program:
STTR
Contract:
F49620-02-C-0059
Solitcitation Year:
N/A
Solicitation Number:
N/A
Branch:
Air Force
Award Year:
2002
Phase:
Phase I
Agency Tracking Number:
F023-0108
Solicitation Topic Code:
N/A
Small Business Information
Combustion Research & Flow Technology, Inc.
174 North Main Street, P.O. Box 1150, Dublin, PA, 18917
Hubzone Owned:
N
Woman Owned:
N
Socially and Economically Disadvantaged:
N
Duns:
929950012
Principal Investigator
 Neeraj Sinha
 Vice President & Technical Director
 (215) 249-9780
 sinha@craft-tech.com
Business Contact
 Neeraj Sinha
Title: Vice President & Technical Director
Phone: (215) 249-9780
Email: sinha@craft-tech.com
Research Institution
 U.Miss/Nat'L Cntr. For Phys. Acoust
 John M Seiner
 1 Coliseum Drive
University, MS, 38677
 (662) 915-5630
 Nonprofit college or university
Abstract
"Laser beam interactions with free shear turbulent structures in the context of a recessed cavity window will be investigated. The proposed program will investigate the aero-optic degradation of a laser beam, housed within the cavity, and its remediationusing high frequency flow control. Beam wander and displacement statistics, obtained via a Position Sensitive Detector (PSD), will be complemented by non-intrusive flowfield measurements using Particle Image Velocimetry (PIV), Laser Speckle for densityfluctuations, Schlieren, etc. Using a previously generated very high-resolution database of high quality, temporal Large Eddy Simulation data, turbulent length-scales, phase-velocity, turbulent kinetic energy spectrum, cross-correlations, etc. will beextracted for the cavity shear layer. Mechanisms underlying effectiveness of high frequency control will be identified and correlated with growth of vortical, large-scale structures. Analytical predictions of beam displacement will be performed andcompared with measurements. A Low Dimensional Model, based on Proper Orthogonal Decomposition (POD), will be used to examine alternate time-dependent strategies for control of turbulent structures in the cavity flowfield. Ascertaining the ability of flowcontrol to manipulate laser/turbulence interactions, thereby reducing the demand upon any adaptive-optics system, is the underlying goal of the proposed STTR effort. The proposed STTR research will lead to a high frequency actuator design concept, whichcan be directly transitioned to the JSF& UCAV programs. Beyond DE weapons, the flow control technology for reduction of optical degradation by turbulence is of great relevance for reduction of bore-sight-error (BSE) for a tracking system or blurelimination for an imaging system. From the perspective of flow control, the high frequency actuator is closely related to current research in aircraft exhaust noise reduction, exhaust plume infra-red (IR) signature control and weapons bay dynamic loadattenuation."

* information listed above is at the time of submission.

Agency Micro-sites

US Flag An Official Website of the United States Government