Self-sustained oscillations in a cavity arise due to the unsteady separation of boundary layers at the leading edge. The dynamic mode decomposition method was employed to analyze the self-sustained oscillations. Two cavity flow data sets, with or without self-sustained oscillations and possessing thin or thick incoming boundary layers (ReD = 12,000 and 3000), were analyzed. The ratios between the cavity depth and the momentum thickness (D/θ) were 40 and 4.5, respectively, and the cavity aspect ratio was L/D = 2. The dynamic modes extracted from the thick boundary layer indicated that the upcoming boundary layer structures and the shear layer structures along the cavity lip line coexisted with coincident frequency space but with different wavenumber space, whereas structures with a thin boundary layer showed complete coherence among the modes to produce self-sustained oscillations. This result suggests that the hydrodynamic resonances that gave rise to the self-sustained oscillations occurred if the upcoming boundary layer structures and the shear layer structures coincided, not only in frequencies, but also in wavenumbers. The influences of the cavity dimensions and incoming momentum thickness on the self-sustained oscillations were examined.
Description
ScienceDirect.com - International Journal of Heat and Fluid Flow - Dynamic mode decomposition of turbulent cavity flows for self-sustained oscillations
%0 Journal Article
%1 Seena20111098
%A Seena, Abu
%A Sung, Hyung Jin
%D 2011
%J International Journal of Heat and Fluid Flow
%K Abu cavity decomposition dynamic flows mode oscillations self-sustained turbulent
%N 6
%P 1098 - 1110
%R 10.1016/j.ijheatfluidflow.2011.09.008
%T Dynamic mode decomposition of turbulent cavity flows for self-sustained oscillations
%U http://www.sciencedirect.com/science/article/pii/S0142727X11001275
%V 32
%X Self-sustained oscillations in a cavity arise due to the unsteady separation of boundary layers at the leading edge. The dynamic mode decomposition method was employed to analyze the self-sustained oscillations. Two cavity flow data sets, with or without self-sustained oscillations and possessing thin or thick incoming boundary layers (ReD = 12,000 and 3000), were analyzed. The ratios between the cavity depth and the momentum thickness (D/θ) were 40 and 4.5, respectively, and the cavity aspect ratio was L/D = 2. The dynamic modes extracted from the thick boundary layer indicated that the upcoming boundary layer structures and the shear layer structures along the cavity lip line coexisted with coincident frequency space but with different wavenumber space, whereas structures with a thin boundary layer showed complete coherence among the modes to produce self-sustained oscillations. This result suggests that the hydrodynamic resonances that gave rise to the self-sustained oscillations occurred if the upcoming boundary layer structures and the shear layer structures coincided, not only in frequencies, but also in wavenumbers. The influences of the cavity dimensions and incoming momentum thickness on the self-sustained oscillations were examined.
@article{Seena20111098,
abstract = {Self-sustained oscillations in a cavity arise due to the unsteady separation of boundary layers at the leading edge. The dynamic mode decomposition method was employed to analyze the self-sustained oscillations. Two cavity flow data sets, with or without self-sustained oscillations and possessing thin or thick incoming boundary layers (ReD = 12,000 and 3000), were analyzed. The ratios between the cavity depth and the momentum thickness (D/θ) were 40 and 4.5, respectively, and the cavity aspect ratio was L/D = 2. The dynamic modes extracted from the thick boundary layer indicated that the upcoming boundary layer structures and the shear layer structures along the cavity lip line coexisted with coincident frequency space but with different wavenumber space, whereas structures with a thin boundary layer showed complete coherence among the modes to produce self-sustained oscillations. This result suggests that the hydrodynamic resonances that gave rise to the self-sustained oscillations occurred if the upcoming boundary layer structures and the shear layer structures coincided, not only in frequencies, but also in wavenumbers. The influences of the cavity dimensions and incoming momentum thickness on the self-sustained oscillations were examined.},
added-at = {2012-09-20T15:33:21.000+0200},
author = {Seena, Abu and Sung, Hyung Jin},
biburl = {https://www.bibsonomy.org/bibtex/2edf0d08aa7d3330862a0eda31515461c/adisaurabh},
description = {ScienceDirect.com - International Journal of Heat and Fluid Flow - Dynamic mode decomposition of turbulent cavity flows for self-sustained oscillations},
doi = {10.1016/j.ijheatfluidflow.2011.09.008},
interhash = {706e4c71c62bd2827ee604558702d23e},
intrahash = {edf0d08aa7d3330862a0eda31515461c},
issn = {0142-727X},
journal = {International Journal of Heat and Fluid Flow},
keywords = {Abu cavity decomposition dynamic flows mode oscillations self-sustained turbulent},
number = 6,
pages = {1098 - 1110},
timestamp = {2012-09-20T15:41:37.000+0200},
title = {Dynamic mode decomposition of turbulent cavity flows for self-sustained oscillations},
url = {http://www.sciencedirect.com/science/article/pii/S0142727X11001275},
volume = 32,
year = 2011
}