MIXING ENHANCEMENT NEAR SCRAMJET FLAME HOLDERS

Award Information
Agency:
Department of Defense
Branch
Air Force
Amount:
$490,000.00
Award Year:
1988
Program:
SBIR
Phase:
Phase II
Contract:
n/a
Award Id:
5855
Agency Tracking Number:
5855
Solicitation Year:
n/a
Solicitation Topic Code:
n/a
Solicitation Number:
n/a
Small Business Information
21414 - 68th Ave S, Kent, WA, 98032
Hubzone Owned:
N
Minority Owned:
N
Woman Owned:
N
Duns:
n/a
Principal Investigator:
Dr Suresh Menon
(206) 872-8500
Business Contact:
() -
Research Institution:
n/a
Abstract
THE UNSTEADY FLOW PHENOMENA AROUND REALISTIC SCRAMJET FLAME HOLDERS WILL BE STUDIED USING AN EFFICIENT TIME-ACCURATE NUMERICAL SCHEME. NUMERICAL SIMULATION OF A SUBSONIC RAMJET HAS SHOWN AN INTERACTION BETWEEN THE LARGE-SCALE VORTICES AND ACOUSTIC WAVES AT A CHARACTERISTIC NONACOUSTIC EIGENFREQUENCY. IN SUPERSONIC RAMJETS, ACOUSTIC WAVES WILL PROPAGATE UPSTREAM ONLY THROUGH THE SUBSONIC RECIRCULATION ZONE AND MAY INTERACT WITH THE SEPARATED SHEAR LAYER, RESULTING IN SIMILAR OSCILLATIONS. THIS ASPECT OF FEEDBACK MECHANISMS WILL BE STUDIED IN DETAIL AS A FUNCTION OF MACH NUMBER IN THE PROPOSED STUDY. THE EXISTENCE OF THIS TYPE OF FEEDBACK HAS IMPORTANT IMPLICATIONS FOR ENHANCING MIXING AND HENCE INCREASING COMBUSTION EFFICIENCY. SPECTRAL ANALYSIS AND CROSS CORRELATION OF THE TIME VARIATION OF THE PRESSURE AND VORTICITY FLUCTUATIONS AT VARIOUS LOCATIONS WILL BE EMPLOYED TO IDENTIFY THE CHARACTERISTIC FREQUENCY OF OSCILLATION AND WAVE PROPAGATION. THE PROPOSED STUDY WILL DETERMINE WHETHER COUPLING BETWEEN ACOUSTICS AND VORTEX MOTION CAN BE SUSTAINED IN THE VICINITY OF A SCRAMJET FLAME HOLDER AND HOW IT IS AFFECTED BY THE MACH NUMBER OF THE FLOW.

* information listed above is at the time of submission.

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