Time-sparse resolvent analysis
Traditional resolvent analysis assumes a statistically steady flow such that a Fourier transform in the temporal direction can be taken. However, for unsteady flows, the mean profile changes in time, which is not amenable for Fourier transform in time. In order to capture temporally local events in these unsteady flows, a time-sparse resolvent analysis needs to be developed.
We plan to extend the traditional resolvent analysis using various time-sparse techniques to extend the highly valuable tool to unsteady problems.
B. Lopez-Doriga, E. Ballouz, H. J. Bae & S. T. M. Dawson, "A sparsity-promoting resolvent analysis for the identification of spatiotemporally-localized amplification mechanisms," AIAA SciTech, 2023.
E. Ballouz, B. Lopez-Doriga, S. T. M. Dawson & H. J. Bae, "Wavelet-based resolvent analysis for statistically-stationary and temporally-evolving flows," AIAA SciTech, 2023.
Understanding wall-bounded turbulence through resolvent analysis
Resolvent analysis has been an invaluable tool to understand turbulent flows. Here, we use resolvent analysis to better understand wall-bounded turbulence in various configurations, including stratified flows and compressible boundary layers.
M. A. Ahmed, H. J. Bae, A. F. Thompson & B. J. McKeon, "Resolvent analysis of stratification effects on wall-bounded shear flows," Physical Review Fluids 6, 084804, 2021.
H. J. Bae, A. Lozano-Durán & B. J. McKeon, "Nonlinear mechanism of the self-sustaining process in the buffer and logarithmic layer of wall-bounded flows," Journal of Fluid Mechanics 914, A3, 2021.
H. J. Bae, S. T. M. Dawson & B. J. McKeon, "Resolvent-based study of compressibility effects on turbulent boundary layers," Journal of Fluid Mechanics 883, A29, 2020.