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y+ and u+ values with low-Re RANS turbulence models: utility + testcase |
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February 14, 2013, 09:28 |
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#81 | |
New Member
Sha Huang
Join Date: Dec 2012
Posts: 22
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Quote:
Hi: I saw your results of yPlus, the value seems very big, and how can we judg the y+ is in the proper range? |
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April 5, 2013, 13:48 |
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#82 |
Member
Dan Kokron
Join Date: Dec 2012
Posts: 33
Rep Power: 14 |
@post 71.
I posting here as I have not found any other source for the yPlus utility from Daniel WEI. I have attached a patch to allow yPlus.C to be compiled under OpenFOAM-2.2.x. Runs fine in my environment. Please check my work. |
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May 27, 2013, 09:33 |
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#83 | |
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Phillip
Join Date: Mar 2012
Location: Germany
Posts: 27
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Quote:
Hi foamers, i have change the source code of the "plusPostRANS" tool for the usage in OpenFOAM 2.2.0 (see the attached file) Just compile it and it works @romant: i hope this helps.. |
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May 28, 2013, 12:22 |
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#84 | |
Senior Member
Daniel WEI (老魏)
Join Date: Mar 2009
Location: Beijing, China
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Quote:
Sorry, I was too busy. Thanks a lot for your contribution.
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~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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May 29, 2013, 07:47 |
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#85 | |
New Member
Phillip
Join Date: Mar 2012
Location: Germany
Posts: 27
Rep Power: 14 |
Quote:
Hi foamers, firstly thanks for the nice tool. I want to compile the yPlus.C under OpenFoam 2.2.0 and have some errors due to a new header file: they change the name from "basicThermo.H" to "fluidThermo.H" (OpenFoam 2.1.x --> OpenFoam 2.2.x). This is why i change all entries in the source code of "yPlus.C" and it works fine, now. I have attached the new files for OpenFoam 2.2.x: |
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May 29, 2013, 07:56 |
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#86 | |
New Member
Phillip
Join Date: Mar 2012
Location: Germany
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Quote:
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June 5, 2013, 17:44 |
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#87 |
Senior Member
Ehsan
Join Date: Oct 2012
Location: Iran
Posts: 2,208
Rep Power: 27 |
Hi
is this useful tool appropriate for low-Re turbulent models only or is general? also I have found another tool for yPlus calculating. could someone have a look into it to see if its correct too and what are the differences and which is more suitable for compressible unsteady cases? and also could someone suggest some turbulent methods for compressible unsteady internal flow cases with low-Re mesh(y+<=1) and with wall function(30<=y+<60 or 100 in some unsteady cases) thanks. ---------------------------------------------------------- complement: in the file I have attached the fomula of yPlus is: Code:
yPlus.boundaryField()[patchi] = y[patchi] * sqrt ( mut.boundaryField()[patchi] * mag(U.boundaryField()[patchi].snGrad()) / rho.boundaryField()[patchi] ) / (RASModel->mu().boundaryField()[patchi]/rho.boundaryField()[patchi]); Code:
yPlus.boundaryField()[patchi] = d[patchi] *sqrt ( rho.boundaryField()[patchi] *muEff.boundaryField()[patchi] *mag(U.boundaryField()[patchi].snGrad()) ) /muLam.boundaryField()[patchi]; (if there are other differences anyone notices please let me know)
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Injustice Anywhere is a Threat for Justice Everywhere.Martin Luther King. To Be or Not To Be,Thats the Question! The Only Stupid Question Is the One that Goes Unasked. |
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July 19, 2013, 12:03 |
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#88 |
Senior Member
Join Date: Mar 2010
Posts: 181
Rep Power: 17 |
Hi Dan,
just a heads up to say thanks for the x2 tools - worked great for me and i thought well distributed functionality (i.e. in terms of separating yStar / yPlus / refinedWallLayer etc). much appreciated Jon |
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August 5, 2013, 03:48 |
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#89 |
Member
Glenn Carlson, PE, PhD (ret)
Join Date: Oct 2012
Location: US
Posts: 49
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I'm having trouble building yPlus with wmake. I have no problem running OF 2.2.1 in Ubuntu 12.04 64-bit.
I extracted yPlus.c and the Make folder to /opt/openfoam221/src. It seems that, according to http://www.openfoam.org/docs/user/co...0-720003.2.2.1, all I need to do is run wmake (no arguments, no directory) from /opt/openfoam221/src/yPlus. But when I run wmake, I get the following errors. gac@gac-vm01:/opt/openfoam221/src/yPlus$ wmake mkdir: cannot create directory `linuxGccDPOpt': Permission denied /bin/sh: 1: cannot create linuxGccDPOpt/options: Directory nonexistent make: *** [linuxGccDPOpt/options] Error 2 /opt/openfoam221/wmake/MakefileFiles:40: linuxGccDPOpt/options: No such file or directory make: *** No rule to make target `linuxGccDPOpt/options'. Stop. wmake error: file 'Make/linuxGccDPOpt/objectFiles' could not be created in /opt/openfoam221/src/yPlus Thanks for any assistance. Regards, Glenn |
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August 5, 2013, 03:58 |
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#90 |
Senior Member
Bernhard
Join Date: Sep 2009
Location: Delft
Posts: 790
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Try either "sudo wmake" if you have root privileges, or compile it from a directory where you do have write access, e.g. "cd $WM_PROJECT_USER_DIR"
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August 5, 2013, 04:27 |
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#91 |
Member
Glenn Carlson, PE, PhD (ret)
Join Date: Oct 2012
Location: US
Posts: 49
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Thanks for quick reply.
Extracting yPlus.c and Make folder to $WM_PROJECT_USER_DIR/yPlus helped (proper permissions), but I get another permission error when I run wmake from there: gac@gac-vm01:~/OpenFOAM/gac-2.2.1/yPlus$ wmake Making dependency list for source file yPlus.C SOURCE=yPlus.C ; g++ -m32 -Dlinux -DWM_DP -Wall -Wextra -Wno-unused-parameter -Wold-style-cast -O3 -DNoRepository -ftemplate-depth-100 -I/opt/openfoam221/src/meshTools/lnInclude -I/opt/openfoam221/src/turbulenceModels -I/opt/openfoam221/src/transportModels -I/opt/openfoam221/src/thermophysicalModels/basic/lnInclude -I/opt/openfoam221/src/finiteVolume/lnInclude -IlnInclude -I. -I/opt/openfoam221/src/OpenFOAM/lnInclude -I/opt/openfoam221/src/OSspecific/POSIX/lnInclude -fPIC -c $SOURCE -o Make/linuxGccDPOpt/yPlus.o g++ -m32 -Dlinux -DWM_DP -Wall -Wextra -Wno-unused-parameter -Wold-style-cast -O3 -DNoRepository -ftemplate-depth-100 -I/opt/openfoam221/src/meshTools/lnInclude -I/opt/openfoam221/src/turbulenceModels -I/opt/openfoam221/src/transportModels -I/opt/openfoam221/src/thermophysicalModels/basic/lnInclude -I/opt/openfoam221/src/finiteVolume/lnInclude -IlnInclude -I. -I/opt/openfoam221/src/OpenFOAM/lnInclude -I/opt/openfoam221/src/OSspecific/POSIX/lnInclude -fPIC -Xlinker --add-needed -Xlinker --no-as-needed Make/linuxGccDPOpt/yPlus.o -L/opt/openfoam221/platforms/linuxGccDPOpt/lib \ -lcompressibleTurbulenceModel -lcompressibleRASModels -lcompressibleLESModels -lincompressibleTurbulenceModel -lincompressibleTransportModels -lincompressibleRASModels -lincompressibleLESModels -lfiniteVolume -lgenericPatchFields -lOpenFOAM -ldl -lm -o /opt/openfoam221/platforms/linuxGccDPOpt/bin/yPlus /usr/bin/ld: cannot open output file /opt/openfoam221/platforms/linuxGccDPOpt/bin/yPlus: Permission denied collect2: ld returned 1 exit status When I run 'sudo wmake', I get the error 'sudo: wmake: command not found'. Perhaps next time I will not install OpenFOAM as root. Thanks again. |
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August 5, 2013, 05:08 |
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#92 |
Member
Glenn Carlson, PE, PhD (ret)
Join Date: Oct 2012
Location: US
Posts: 49
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I successfully built yPlus by changing 'FOAM_APPBIN' in Make/files to 'FOAM_USER_APPBIN'.
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October 15, 2013, 18:12 |
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#93 |
Senior Member
Daniel WEI (老魏)
Join Date: Mar 2009
Location: Beijing, China
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Hey guys,
1. I found calculate wall distance twice is unnecessary, so I disable it. 2. Here are the two utilities doing the same job as before, with small changes. Tested on OpenFOAM-2.2.x 3. I have also added a few write-out control. Please use "-help" to find more info. yPlus: yPlus.tar.gz yStar: yStar.tar.gz
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~ Daniel WEI ------------- Boeing Research & Technology - China Beijing, China |
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November 24, 2013, 21:42 |
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#95 |
New Member
borhan
Join Date: May 2011
Posts: 5
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Dear all,
This issue was already discussed in some length in various threads. Therefore I finally reviewed and attached my plusPostRANS utility. It calculates y+ and u+ values when using one of the available low-Re RANS turbulence models. I hope the code as well as the output will be self-explaining I also attached a case. It is a straight pipe (wedge) with periodic inlet/outlet boundary conditions. The Reynolds number based on the mean axial velocity is Re=5300. You can run the case using pisoFoam. I would appreciate any feedback, it might be still improved at some point! Best regards, Florian |
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November 24, 2013, 21:50 |
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#96 |
New Member
borhan
Join Date: May 2011
Posts: 5
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Dear all,
This issue was already discussed in some length in various threads. Therefore I finally reviewed and attached my plusPostRANS utility. It calculates y+ and u+ values when using one of the available low-Re RANS turbulence models. I hope the code as well as the output will be self-explaining I also attached a case. It is a straight pipe (wedge) with periodic inlet/outlet boundary conditions. The Reynolds number based on the mean axial velocity is Re=5300. You can run the case using pisoFoam. I would appreciate any feedback, it might be still improved at some point! Best regards, Florian Dear Florian, I guess you have been discussing about y+. I have a series of experimental data (u as velocity and y as normal distance+ u free stream+ characteristic length) and I would like to u* and then y+ as well as u+...I was wondering if you or any friend can help me in this respect. |
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February 25, 2014, 17:14 |
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#97 | |
Senior Member
Join Date: Nov 2012
Location: Bavaria
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Dear borhanalhoseini,
is there a working version of yPlusUplus (or plusPostRANS) for OF.2.2.2 for LES simulations (NWR) that calculates the fields - as originally intended by florian_krause - to be able to create plots u+ vs. y+? Quote:
Thank you ! Aylalisa Last edited by aylalisa; February 26, 2014 at 04:10. |
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April 28, 2014, 06:11 |
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#98 |
Senior Member
ArathoN
Join Date: Jul 2011
Posts: 137
Rep Power: 16 |
The best way is to simulate the case then use the wallshearstress to calculate tau or the yplus (you'll have yplus and y so you can derive utau). At this point you have all the needed data to calculate uplus.
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April 29, 2014, 04:48 |
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#99 |
Senior Member
Join Date: Nov 2012
Location: Bavaria
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Hello ArathoN,
documentation for wallShearStress utility says: 'Calculates and writes the wall shear stress, for the specified times when using RAS turbulence models. ' This description prevented me to use it. The computation of stress is 'stress tensor * vector', that is what wallShearStress utility does. Why does the documentation insist on RAS turbulence models Aylalisa |
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April 29, 2014, 07:09 |
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#100 | |
Senior Member
ArathoN
Join Date: Jul 2011
Posts: 137
Rep Power: 16 |
Quote:
Never noticed that part, unfortunately my C++ knowledge is almost null so i can't delve into the appropriate code. If you have the yPlus, y and the cinematic viscosity you can calculate the friction velocity (utau) and from it you can compute the uPlus. My only problem here would be how to consider the utau, because I'm certain it is variable on the domain so it's better to averag it (in my opinion) but I'm not certain about this. P.S Another doubt what section would you consider when you want to compare the simulated data with the experimental data for example in a channel? |
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Tags |
low-re rans, y* value, y+ value |
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