
[Sponsors] 
October 2, 2008, 15:49 
Dear all,
About the 1st que

#41 
Senior Member

Dear all,
About the 1st question my post on Sep 21, that is: The three point coordinates are (4.41226e05,5.79779e05), (4.71079e05,6.24456e05), (4.2272e05,5.92143e05); The circle center coordinate is:(4.469e05,6.083e05)this is correct, I have compared with gmsh geo file The diamter of the circle is:5.81612e06however, the diameter should be 5.93 micrometer (I am sure the equation to calculate diameter is right: 2*sqrt(....)). In order to check why, I plot the following pictures, Pic 1 from Gmsh geometry, Pic 2 with the output information. Pic 1 Pic 2 Finding: I need to check if the one point coordinate of three points are the point on the circle? I could not find them in the file constant/polyMesh/points!!! is the point the middle of the circle points? (I guess) I have two png figures. I find point 1143 coordinate is: (4.25934e05 5.87334e05 0) while our one point output (the one near point 12) is: (4.41226e05,5.79779e05,5e06), while point 12 is: (4.469e05 5.7865e05 0) The way I get these three points: const vectorField & pp = patch().Cf(); vector p0, p1, p2; if (pp.size() >= 3) { p0 = pp[0]; p1 = pp[1]; p2 = pp[2]; } I could not fully understand this numerical discrepancy. would you please give me any hint? Thank you for your attention. Bin 

October 3, 2008, 04:26 
After test, I know that my way

#42 
Senior Member

After test, I know that my way to get the point coordinate is wrong,
const vectorField & pp = patch().Cf(); I must find a way out. 

October 4, 2008, 12:12 
Today I compared the Gmsh poin

#43 
Senior Member

Today I compared the Gmsh points coordinates with the file "points", at last I am sure:
const vectorField & pp = patch().Cf(); could return the middle point of each mesh face. Then I think since the function Cf() could get the point coordinate, I many use the way it used. I find "makeFaceCentresAndAreas" in "primitiveMeshFaceCentresAndAreas.C", Then I use the way it used:  vector p0, p1, p2; const pointField& p=points(); const faceList& fs = faces(); forAll (fs, facei) { const labelList& f = fs[facei]; p0=p[f[0]]; p1=p[f[1]]; p2=p[f[2]]; }  when I compile, I get:  error: 'points' was not declared in this scope error: 'faces' was not declared in this scope Since we are already in the "circleSlip" type, I do not want to use label patchID = mesh.boundaryMesh().findPatchID("circle"); to specify the patch.Otherwise we need many findPatchID("circle1"), findPatchID("circle2")....; This is not what I want, just like the slip already in OpenFOAM, whenever sb want circleSlip boundary, it could get the points on the circle. If you have any hints about this, i.e. how to get the point coordinates, I would like to thank you in advance. I must conquer this even though I may not good at OpenFOAM. Thank you for attention. Best regards, bin 

October 5, 2008, 15:38 
Could I ask in OpenFOAM, which

#44 
Senior Member

Could I ask in OpenFOAM, which plane we are using for the 2D models? Is it in the front(z=0)? in the back(z=1e5)? or in the middle plane(5e6)?
Best regards, Bin 

October 6, 2008, 06:12 
It is solved about how to get

#45 
Senior Member

It is solved about how to get the diameter for a circle patch.
If anyone needs this, just write to me: zhoubinwx@hotmail.com let me go on with the boundary condition setting, and hope to finish soon and correctly. Bin 

October 9, 2008, 12:49 
Dear foamers,
After I imple

#46 
Senior Member

Dear foamers,
After I implement my boundary, the simulation goes on for several minutes, but then I get an error, please allow me to post it here, to see if some friends have experience dealing with this. The error is: #0 Foam::error::printStack(Foam:stream&) in "/home/zhou/OpenFOAM/OpenFOAM1.5/lib/linuxGccDPOpt/libOpenFOAM.so" #1 Foam::sigFpe::sigFpeHandler(int) in "/home/zhou/OpenFOAM/OpenFOAM1.5/lib/linuxGccDPOpt/libOpenFOAM.so" #2 Uninterpreted: [0xffffe420] #3 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/home/zhou/OpenFOAM/OpenFOAM1.5/lib/linuxGccDPOpt/libOpenFOAM.so" #4 Foam::fvMatrix<foam::vector<double> >::solve(Foam::Istream&) in "/home/zhou/OpenFOAM/OpenFOAM1.5/applications/bin/linuxGccDPOpt/simpleFoam" #5 Foam::lduMatrix::solverPerformance Foam::solve<foam::vector<double> >(Foam::tmp<foam::fvmatrix<foam::vector<double> > > const&) in "/home/zhou/OpenFOAM/OpenFOAM1.5/applications/bin/linuxGccDPOpt/simpleFoam" #6 main in "/home/zhou/OpenFOAM/OpenFOAM1.5/applications/bin/linuxGccDPOpt/simpleFoam" #7 __libc_start_main in "/lib/libc.so.6" #8 Foam::regIOobject::readIfModified() in "/home/zhou/OpenFOAM/OpenFOAM1.5/applications/bin/linuxGccDPOpt/simpleFoam" If you know, please let me know. Really appreciate your attention. Best regards, Bin 

June 29, 2011, 17:39 
volVectorField_Tangential Component

#47 
New Member
Kelvin
Join Date: Jan 2011
Posts: 5
Rep Power: 7 
Dear Zhou Bin,
I try to find tangential component of gradient. I read all of your posts. Did you define tangential components of any vector as a volVectorField. You wrote previous post, volVectorField U_t=U_n*(n&U) How can you define it??? This thread is very old maybe you got it so I want to ask you? Thank you for your helping. 

March 1, 2013, 07:49 

#48 
New Member
Mussie
Join Date: Feb 2011
Posts: 7
Rep Power: 7 
Hi,
as we all know all of us learn from mistakes others committed while dealing with CFD. That is why we visit the site to get ideas and to learn from others mistakes and to share our mistakes and ideas. Hence, I would like you to post how you solve your problem as I encounter the same error flag message with s similar act to implement a rampedFixedValue BC. Cheers! 

March 1, 2013, 07:55 

#49  
New Member
Mussie
Join Date: Feb 2011
Posts: 7
Rep Power: 7 
Quote:
Thanks! 

March 1, 2013, 07:59 

#50  
New Member
Mussie
Join Date: Feb 2011
Posts: 7
Rep Power: 7 
Quote:
I think you make a mistake in writing the boundary type you just created as rampedFixValue rather than rampedFixedValue , hopefully that may be one cause from what can be sen from the displayed code. Cheers! 

March 2, 2013, 07:59 

#51  
New Member
Mussie
Join Date: Feb 2011
Posts: 7
Rep Power: 7 
Quote:
what was the problem and how did you solve it? 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Boundary details, free slip or no slip?  Tiago  CFX  5  August 20, 2013 22:54 
Circle of circles  Andore  Main CFD Forum  1  February 8, 2008 15:45 
Modelling with many circles in a rectangle  gdbaldw  OpenFOAM PreProcessing  37  November 27, 2007 05:30 
Slip Boundary Condition for Moving Boundary  Shukla  Main CFD Forum  3  November 11, 2005 16:02 
Slip boundary for N.S.  Rasmus  Main CFD Forum  0  June 6, 2002 08:49 