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February 13, 2010, 08:53 |
reference area
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#1 |
Senior Member
Andrea Pasquali
Join Date: Sep 2009
Location: Germany
Posts: 142
Rep Power: 17 |
Hi,
Is there in OF a code to calculate the frontal area "Aref" (for example the car frontal area) to calculate Cx and Cz using "forceCoeffs" function? Thanks, Andrea
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Andrea Pasquali |
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February 14, 2010, 10:33 |
liftDrag
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#2 |
Senior Member
Andrea Pasquali
Join Date: Sep 2009
Location: Germany
Posts: 142
Rep Power: 17 |
Hello,
I found "liftDrag" application for OF1.4. I try to compile it on my OF 1.6.x without success... Does any version exist for OF1.6 or 1.6.x ? Does this application calculate the frontal area "Aref" ? Thanks for any help! Andrea
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Andrea Pasquali |
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May 5, 2010, 11:41 |
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#3 |
Senior Member
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Hi Andrea,
I am also looking for a way to easily calculate the frontal area of a complex 3D body. So far, it seems the only way to do it would be to sum the (area vectors dot the normal vector) on a whole physical surface and ignore negative values (to avoid having a zero total area!). The code involved would look something like Code:
mesh.Sf().boundaryField() and a loop like Code:
forAllConstIter(labelHashSet, patchSet_, iter) Best regards, -Louis |
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May 17, 2010, 21:13 |
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#4 |
Senior Member
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I have looked into it some more and here's the exact command that will give you the frontal area (in x-direction)...
Code:
Info << "***********" << ( sumMag(Sfb[patchi].component(vector::X))/2 ) << "***************" << endl; -Louis EDIT: that formula only works if the part has no concavity (ie: holes inside) because this would count areas that should not be counted... Last edited by louisgag; May 18, 2010 at 17:19. |
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June 10, 2010, 03:20 |
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#5 |
Member
Björn Bergqvist
Join Date: Mar 2009
Location: Gothenburg, Västra Götaland, Sweden
Posts: 43
Rep Power: 17 |
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________________________________________ Björn Bergqvist, creator of Discretizer, a free mesh generator for OpenFOAM _________http://www.discretizer.org_____________
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August 4, 2010, 17:55 |
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#6 |
Senior Member
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thanks for this very useful link. Just a note, if your shape contains some concavities you need to select cells through (or actually skip the extract selection step) and then divide the final result by two.
Cheers, -Louis |
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August 5, 2010, 05:31 |
reference area
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#7 |
Senior Member
NAVEEN.K.M
Join Date: Mar 2009
Location: Bangalore, Karnataka, india
Posts: 114
Rep Power: 17 |
hi louisgag,
Total area can be calculated using the liftdrag utility in OpenFOAM 1.4.1 by running liftDrag and put the same area at the end of controlDict of OpenFOAM 1.6.... Regards, Naveen |
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August 5, 2010, 14:00 |
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#8 |
Senior Member
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Thanks Naveen.
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