LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)
-
Upload
britanni-singleton -
Category
Documents
-
view
42 -
download
3
description
Transcript of LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)
![Page 1: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/1.jpg)
1
LES of Turbulent Flows: Lecture 4(ME EN 7960-003)
Prof. Rob StollDepartment of Mechanical Engineering
University of Utah
Fall 2014
![Page 2: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/2.jpg)
2
LES Filters and their transfer functions
Real Space Filters Filter Transfer Function
Only the Gaussian filter is local in both real and wave space
![Page 3: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/3.jpg)
3
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).
![Page 4: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/4.jpg)
4
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).
![Page 5: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/5.jpg)
5
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).
![Page 6: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/6.jpg)
6
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).
![Page 7: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/7.jpg)
7
Filtering Turbulence (wave space)
π/Δ2
π/Δ1
π/Δ2
π/Δ1
π/Δ2
π/Δ1
![Page 8: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/8.jpg)
8
Filtering Turbulence (wave space)
π/Δ1 π/Δ2
Comparison between different filters
![Page 9: LES of Turbulent Flows: Lecture 4 (ME EN 7960- 003)](https://reader035.fdocuments.in/reader035/viewer/2022062319/56813099550346895d967bad/html5/thumbnails/9.jpg)
9
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