Turbulence Modelling 18 - Surface Roughness in log law of the wall part i
8Petroleum Downstream Crash Course Playlist:
https://www.youtube.com/playlist?list=PLhPfNw4V4_YQ13CnhacUqEVk-tZlU4ISE
OpenFOAM for Windows 10 Beginner Playlist
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OpenFOAM Intermediate Playlist
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Radiation Heat Transfer Learning Journal:
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Turbulence Modelling Playlist
https://www.youtube.com/watch?v=F_Rxv9uMM3g&list=PLhPfNw4V4_YSnbYkJIBQ1kRN06Mmxe2Be
Shoutout to Fluid Mechanics 101
https://www.youtube.com/watch?v=vYbRUmVTmGM
Law of the Wall (wikipedia)
https://en.wikipedia.org/wiki/Law_of_the_wall
Accounting for wall roughness effects in turbulence models : a wall function approach
https://www.eucass.eu/doi/EUCASS2017-372.pdf
The sand grain height hs is an estimate of surface roughness.
How does this relate to the surface roughness (epsilon) in moody chart?
To correlate both, we can see the Nikuradse paper
https://ntrs.nasa.gov/search.jsp?R=19930093938
https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19930093938.pdf
Moody Chart Engineering Toolbox
https://www.engineeringtoolbox.com/moody-diagram-d_618.html
Surface Roughness Typical Value Engineering Toolbox
https://www.engineeringtoolbox.com/surface-roughness-ventilation-ducts-d_209.html
Get this (trivia):
Nikuradse was Ludwig Prandtl’s PhD student, both were Germans
And Prandtl was involved in Nazi Germany’s Regime, and there was quite some political involvement. Yes the same guy with which we get our Prandtl number. He was involved with Nazi Germany’s air force (Luftwaffe) research, can u believe it???
Here’s the paper in case you’re interested
https://www.sciencedirect.com/science/article/pii/S1631072117300815