Active Control of Supersonic Impinging JetsExperimental studies of supersonic impinging jet flows suggest that they are greatly influenced by the flow-acoustic interactions through a feedback mechanism. The self-sustained oscillations of the jet column observed in these flows result in high velocities in the ambient medium induced by the large-scale coherent vortical structures in the jet shear layers. As a consequence, the suck down force on the surface from which the jet is issuing can reach as high as 60% of the primary jet thrust. In addition, the overall sound pressure levels (OASPL) increase significantly relative to a free jet. To alleviate these undesirable flow and acoustic characteristics, a novel control technique using supersonic microjets is demonstrated. Sixteen supersonic microjets are placed around the circumference of the main jet at the nozzle exit to disrupt the feedback mechanism. As a result, significant lift loss recovery (approximately 50%) and reduced near field OASPL (approximately 7 dB) are observed.
Document ID
20010067682
Acquisition Source
Ames Research Center
Document Type
Conference Paper
Authors
Krothapalli, A. (Florida Agricultural and Mechanical Univ. Tallahassee, FL United States)
Elavarasan, R. (Florida Agricultural and Mechanical Univ. Tallahassee, FL United States)
Alvi, F. (Florida Agricultural and Mechanical Univ. Tallahassee, FL United States)
Shih, C. (Florida Agricultural and Mechanical Univ. Tallahassee, FL United States)
Wardwell, Doug
Date Acquired
August 20, 2013
Publication Date
June 1, 2001
Publication Information
Publication: Active Control Technology for Enhanced Performance Operational Capabilities of Military Aircraft, Land Vehicles and Sea Vehicles