Forcing statistics in resolvent analysis: application in minimal turbulent Couette flow

Abstract

Abstract

Closing the loop: nonlinear Taylor vortex flow through the lens of resolvent analysis

“…We note that similar instances of destructive interference have been observed by other authors such as Nogueira et al. (2021) in their analysis of forcing statistics in PCF and Rosenberg & McKeon (2019 b ) in their interpretation of the Orr–Sommerfeld/Squire decomposition of the resolvent operator.

Figure 9.Projections of the velocity due to individual triadic interactions onto the full Fourier mode summed over common wavenumbers at (red diamonds), (blue squares) and (black circles).

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“…(2021) and Nogueira et al. (2021) have directly computed the nonlinear forcing statistics for minimal channel and Couette flow respectively, and analysed the efficacy of low-rank resolvent reconstructions in capturing the relevant dynamics.…”

Nozzle dynamics and wavepackets in turbulent jets

“…2021; Nogueira et al. 2021). Nonetheless, if the resolvent operator has significant gain separation, studied in detail in § 4, the leading response mode from resolvent analysis is expected to be close to the first SPOD mode regardless of the specific details of the forcing, as the much larger gain of the first mode leads to its dominance in the fluctuation statistics (Beneddine et al.…”

Linear-model-based estimation in wall turbulence: improved stochastic forcing and eddy viscosity terms

“…2017; Nogueira et al. 2021), we still keep the simplification of white-in-time forcing in the present study. This is because the inclusion of the eddy viscosity term in the linear models approximately plays the same role as the colour in the forcing statistics (Zare et al.…”

“…Although the colour of the forcing statistics is important (Nogueira et al. 2021; Zare, Jovanović & Georgiou 2017), the inclusion of the eddy viscosity term in (1.5) partly compensates for the lack of colour in the white-in-time forcing as noted by Zare et al. (2017) and Morra et al.…”