Broadband reconstruction of inhomogeneous turbulence using spectral proper orthogonal decomposition and Gabor modes. (10th April 2020)

• Record Type: Journal Article
• Authors: Ghate, A. S.; Towne, A.; Lele, S. K.
• Is Part Of: Journal of fluid mechanics. Volume 888(2020)
• Publication Date: 2020-04-10
• Subjects: shear layer turbulence; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2020.78
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract : Abstract : A new methodology to construct three-dimensional, temporally stationary but spatially inhomogeneous, incompressible turbulence is presented. The method combines use of the data-driven spectral proper orthogonal decomposition (SPOD) to identify and isolate large-scale coherent motions of the flow, together with a physics-based enrichment algorithm using spatiotemporally localized Gabor modes that capture the inertial subrange turbulence. This fusion of data-driven and physics-based methods enables a statistically correct reconstruction of broadband turbulent flows using fewer modes than would be required using SPOD alone. To demonstrate the approach, we consider the problem of reconstructing wake turbulence on a plane downstream of a dragging actuator disk impinged by homogeneous isotropic turbulence. The reconstructed flow has single- and two-point correlations that are consistent with the reference high-resolution simulation data and could be used to generate statistically consistent inflow boundary conditions for subsequent simulations.