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September 21, 2012, 14:54 |
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#41 | |
Member
Tayo
Join Date: Aug 2012
Posts: 94
Rep Power: 14 |
Quote:
Last edited by tayo; September 22, 2012 at 01:45. |
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October 10, 2013, 15:45 |
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#42 |
Member
Hrushikesh Khadamkar
Join Date: Jul 2010
Location: Mumbai
Posts: 68
Rep Power: 16 |
Hi,
Here is the updated version of baryCenter (for OF-2.2.1) baryCenter221.zip utility. I have tested it on OpenFOAM-2.2.1. Enjoy! |
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November 16, 2013, 13:27 |
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#43 |
Senior Member
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Dear Sebastian,
i want to compute the rise velocity. After you got your center file and you use it in Matlab, how do you compute exactely the rise velocity for each time step? v(n-time) = ( barycentre(n) -barycentre (n-1) )/ deltaT or v(n-time) = ( barycentre(n) -barycentre (0) ) / ( t(n)- t (0) ) ?? Thanks in advance Marco |
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January 6, 2014, 02:30 |
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#44 | |
New Member
Nazanin
Join Date: Sep 2013
Posts: 22
Rep Power: 13 |
Quote:
Thank you for provide baryCenter.. But,how I can use this?I simulate rising bubble and I want calculate rising velocity,bubble diameter and surface area..but I don't know how define these?? can You help me?? Best |
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May 21, 2016, 14:02 |
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#45 |
Member
Arsalan
Join Date: Jul 2014
Posts: 74
Rep Power: 12 |
Dear Foamers,
Is there a way to compute two or three bubbles center position an velocity with swak4Foam?! I used a swakEpression as follows for calculating a single bubble center of position, but for two bubble, I don't have any idea! Code:
bubbleCentreY { type swakExpression; valueType internalField; verbose true; variables ( "Vol= sum (alpha1 < 0.5 ? vol() : 0);" "VolY= sum (alpha1 < 0.5 ? pos().y*vol() : 0);" ); expression "VolY/Vol"; accumulations ( min ); } Regards. |
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May 31, 2017, 05:41 |
How to make 2D bubble region in openfoam?
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#46 | |
New Member
David
Join Date: May 2017
Posts: 2
Rep Power: 0 |
Quote:
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March 8, 2022, 02:54 |
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#47 |
Member
sadra mahmoudi
Join Date: Feb 2021
Location: Austria
Posts: 39
Rep Power: 5 |
Hello Sebastian,
Thank you for the info you provided here. I am also working on the terminal velocity of bubbles. Using the paraView, I measure the center of a bubble location in two successive time step, then by deviding the displacement of the center of bubble to the time difference, I wannt to calculate the velocity. The problem is, the value that I gain is 50 % lower than the reported values in the literature. I am using a 2D mesh in openFoam 8 using interFoam. The contents of my 0 folder are: U file: dimensions [0 1 -1 0 0 0 0]; internalField uniform (0 0 0); boundaryField { bottom { type noSlip; } outlet { type noSlip; } walls { type slip; } defaultFaces { type empty; } } p_rgh file: dimensions [1 -1 -2 0 0 0 0]; internalField uniform 0; boundaryField { bottom { type zeroGradient; } outlet { type zeroGradient; } walls { type zeroGradient; } defaultFaces { type empty; } } alpha file: dimensions [0 0 0 0 0 0 0]; internalField uniform 0; boundaryField { bottom { type zeroGradient; } outlet { type zeroGradient; } walls { type zeroGradient; } defaultFaces { type empty; } } transportProperties file: phases (air water); air { transportModel Newtonian; nu nu [ 0 2 -1 0 0 0 0 ] 1.5E-5; rho rho [ 1 -3 0 0 0 0 0 ] 1.18; } water { transportModel Newtonian; nu nu [ 0 2 -1 0 0 0 0 ] 7.22E-7; rho rho [ 1 -3 0 0 0 0 0 ] 995.7; } Thanks a lot. |
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March 12, 2022, 06:19 |
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#48 |
Senior Member
Uwe Pilz
Join Date: Feb 2017
Location: Leipzig, Germany
Posts: 744
Rep Power: 15 |
I simulated a similar case a few years agao. I did not look at the velocity but at they y value of the center of gravity, which is more or less the same. I get decent values only with veryl low values of maxCo, around 0.01.
__________________
Uwe Pilz -- Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950) |
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March 7, 2024, 17:57 |
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#49 | |
Member
sajad
Join Date: Aug 2013
Posts: 71
Rep Power: 13 |
Quote:
You can see test cases and validations of different bubble regimes in this post: Validation of Bubble Regime in Openfoam #openFoam #bubble_velocity #validation #interFoam |
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