Wavelet decomposition of forced turbulence: Applicability of the iterative Donoho-Johnstone threshold
Lord, J., Rast, M., McKinlay, C., Clyne, J. P., & Mininni, P. D. (2012). Wavelet decomposition of forced turbulence: Applicability of the iterative Donoho-Johnstone threshold. Physics Of Fluids, 24, 025102. doi:10.1063/1.3683556
We examine the decomposition of forced Taylor-Green and Arn'old-Beltrami-Childress (ABC) flows into coherent and incoherent components using an orthonormal wavelet decomposition. We ask whether wavelet coefficient thresholding based on the Donoho-Johnstone criterion can extract a coherent vortex ... Show moreWe examine the decomposition of forced Taylor-Green and Arn'old-Beltrami-Childress (ABC) flows into coherent and incoherent components using an orthonormal wavelet decomposition. We ask whether wavelet coefficient thresholding based on the Donoho-Johnstone criterion can extract a coherent vortex signal while leaving behind Gaussian random noise. We find that no threshold yields a strictly Gaussian incoherent component, and that the most Gaussian incoherent flow is found for data compression lower than that achieved with the fully iterated Donoho-Johnstone threshold. Moreover, even at such low compression, the incoherent component shows clear signs of large-scale spatial correlations that are signatures of the forcings used to drive the flows. Show less