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Implementation of trip in Boundary Layer flow |
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#1 |
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Pedro
Join Date: Feb 2016
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Hi All,
I am trying to implement a numerical tripping by applying a Gaussian force in the wall-normal direction in OpenFOAM. The reason for this implementation is that I'd like to force the transition to turbulence in flat plate boundary layer flow. This idea can be done by adding a term to the momentum equation of the solver. The volume force has been defined in Schlatter and Orlu (2012) "Schlatter, P., & Örlü, R. (2012). Turbulent boundary layers at moderate Reynolds numbers: inflow length and tripping effects. Journal of Fluid Mechanics, 710, 5-34." I am seeking help regarding implementation of this force defined in spectral domain (the ineverse Fourier) into the momentum equation in physical domain. Any help is greatly appreciated. Thanks, Pedram Last edited by pedramtx; August 30, 2018 at 18:43. |
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#2 |
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Michael Alletto
Join Date: Jun 2018
Location: Bremen
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Just from the picture you showed it seems that the force is a function of x,y,z,t. The random numbers h are function of z and t. Can you provide some more detail?
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#3 | |
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Pedro
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Quote:
You are right. The random force g is a function of z and t. I want to apply a 1D wavenumber in the spanwise direction. Then the whole term F is expressed by a local Gaussian distribution in z plane. |
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#4 |
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Michael Alletto
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Maybe I did not und understand correctly the question.
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#5 |
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Michael Alletto
Join Date: Jun 2018
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I found by accident this post of Schlatter where he explains how he generated the random harmonic signal: https://lists.mcs.anl.gov/pipermail/nek5000-users/2018-February/005087.html
in order to generate the random source term in order to simulate the boundary layer tipping. |
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#6 | |
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Pedro
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Quote:
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#7 |
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Michael Alletto
Join Date: Jun 2018
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You're welcome
![]() Let me know how it goes. I find the topic interesting |
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#8 |
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Agustín Villa
Join Date: Apr 2013
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Very interesting topic! I will follow it. It is also interesting for me. For the moment, what I do is to use swak4Foam and introduce some disturbances in the wall.
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#9 |
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Pedro
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#10 | |
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Syavash Asgari
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Quote:
Why not use a more sophisticated method like LeMOS or SEM at the inlet? Or a step further ahead, use the method introduced by Lund et al. (JCP 1998) in your simulation. Regards, Syavash |
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#11 | |
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Agustín Villa
Join Date: Apr 2013
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Hi Syavash, my case is a natural convection boundary layer, not a forced convection one. The boundary layer starts developing when the wall is heated. If I introduce an inlet flow, I'd have a mixed convection case. I will check later the different approaches you said, I have some colleagues who may be interested. Agustín |
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#12 | |
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Syavash Asgari
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Agustin, Having a naturally developing boundary-layer to turbulence should be very interesting, and challenging! Actually I got very interested in this problem. Could you please provide me a snapshot of your simulation? Also would you introduce me a paper dealing with the same problem using LES? Regards, Syavash |
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#13 | |
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Pedro
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Quote:
Thank you for your suggestion. We already captured the turbulent BL using Lund method, but the current simulation aims at resolving the transition behavior of BL. As you may know, rescaling procedure in Lund method necessitates equilibrium state (developed turbulent field) at recycling station. Thanks, Pedram Last edited by pedramtx; September 20, 2018 at 12:58. |
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#14 | |
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Jin Zhang
Join Date: May 2018
Location: Germany
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Quote:
I also find this numerical tripping quite interesting. Although it's been a long time since you last posted, I am still very curious about how this method is implemented in OpenFOAM. Have you already solved this problem? I would appreciate it if you could share your code or give me some clues on how to implement it. Thanks. kind regards, Jin |
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