TY - GEN
T1 - First and mack-mode instabilities in a flat-plate boundary layer at mach 4
AU - Flood, John
AU - Taubert, Lutz
AU - Craig, Stuart A.
N1 - Funding Information:
This work was supported by Dr. Eric Marineau, Program Officer, Office of Naval research (ONR) through grant N00014-17-1-2340. The authors would like to acknowledge LST analysis provided by Christoph Hader, Ning Deng, and Hermann Fasel. Additionally, the contributions of fellow students Victor Padilla, Kyle Bearden, Wesley Bohult, Treyton Moore, and Isaac Charcos were greatly appreciated.
Publisher Copyright:
© 2020, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.
PY - 2020
Y1 - 2020
N2 - Boundary layer stability experiments are performed in a Mach 4 quiet wind tunnel on a flat plate. Clusters of surface-mounted, high-frequency pressure transducers are installed at two locations on the model. Transducer clusters allow the computation of cross-spectra and the determination of the phase speeds and wave angles of passing boundary-layer waves. At an edge Mach number of 4, the coexistence of Mack’s first and second modes is of particular interest. Peaks in the autospectral densities provide weak and inconsistent evidence of unstable waves within frequency bands relevant to either mode of interest. Cross-spectral densities show high coherence at frequencies associated with the first mode. Wave angles appear to match well with those predicted for the first mode, while other propagation information matches poorly, likely due to shortcomings in the analysis tools in dealing with low signal to noise ratio situations.
AB - Boundary layer stability experiments are performed in a Mach 4 quiet wind tunnel on a flat plate. Clusters of surface-mounted, high-frequency pressure transducers are installed at two locations on the model. Transducer clusters allow the computation of cross-spectra and the determination of the phase speeds and wave angles of passing boundary-layer waves. At an edge Mach number of 4, the coexistence of Mack’s first and second modes is of particular interest. Peaks in the autospectral densities provide weak and inconsistent evidence of unstable waves within frequency bands relevant to either mode of interest. Cross-spectral densities show high coherence at frequencies associated with the first mode. Wave angles appear to match well with those predicted for the first mode, while other propagation information matches poorly, likely due to shortcomings in the analysis tools in dealing with low signal to noise ratio situations.
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U2 - 10.2514/6.2020-0361
DO - 10.2514/6.2020-0361
M3 - Conference contribution
AN - SCOPUS:85092397758
SN - 9781624105951
T3 - AIAA Scitech 2020 Forum
BT - AIAA Scitech 2020 Forum
PB - American Institute of Aeronautics and Astronautics Inc, AIAA
T2 - AIAA Scitech Forum, 2020
Y2 - 6 January 2020 through 10 January 2020
ER -