les of turbulent flows: lecture 4 (me en 7960- 003)
DESCRIPTION
LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003). Prof. Rob Stoll Department of Mechanical Engineering University of Utah Fall 2014. LES Filters and their transfer functions. Real Space Filters. Filter Transfer Function. Only the Gaussian filter is local in both real and wave space. - PowerPoint PPT PresentationTRANSCRIPT
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LES of Turbulent Flows: Lecture 4(ME EN 7960-003)
Prof. Rob StollDepartment of Mechanical Engineering
University of Utah
Fall 2014
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LES Filters and their transfer functions
Real Space Filters Filter Transfer Function
Only the Gaussian filter is local in both real and wave space
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Filtering Turbulence (real space, cutoff filter)
Note: here (and throughout the presentation) we are using DNS data from Lu et al. (International Journal of Modern Physics C, 2008).
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Filtering Turbulence (real space, Gaussian filter)
Note: here (and throughout the presentation) we are using DNS data from Lu et al. (International Journal of Modern Physics C, 2008).
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Filtering Turbulence (real space, box filter)Note: here (and throughout the presentation) we are using DNS data from Lu et al. (International Journal of Modern Physics C, 2008).
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Filtering Turbulence (real space)Note: here (and throughout the presentation) we are using DNS data from Lu et al. (International Journal of Modern Physics C, 2008).
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Filtering Turbulence (wave space)
π/Δ2
π/Δ1
π/Δ2
π/Δ1
π/Δ2
π/Δ1
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Filtering Turbulence (wave space)
π/Δ1 π/Δ2
Comparison between different filters
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We can use our filtered DNS fields to look at how the choice of our filter kernel affects this separation in wavespace
Decomposition of Turbulence for real filters
π/Δ π/Δ
Resolved scales SGS scales
Resolved SFS
Resolved scales SGS scales