problem with timeVaryingMappedFixedValue

Lorenzo92 · April 23, 2016, 04:17

Hello everyone,

I'm trying to solve a problem in which an inlet patch, called "throat", is defined.
On this patch I would like to impose a time varying boundary condition on pressure, through timeVaryingMappedFixedValue.
I followed the tutorial pitzDailyExptInlet but still I have doubts about the meaning of the files "points" ( under constant/boundaryData/Inlet) and the time directory "0" (under constant/boundaryData). In that case unstedy BC where on U field, here on pressure but that should not be an issue.

So my questions are :
1) what does the file "points" stand for? ( maybe the location in terms of xyz coordinates of points , where time-varying BC is to be applied?)

2)what do I have to specify in constant/boundaryData/throat/0 directory ? ( I thought initially the value at different times of my pressure profile )

I'm rather new to this BC so presumably I am wrong in several points, any help would be very appreciated.

Thanks

laurentD · October 11, 2016, 06:47

Hi Lorenzo,

Quote:

1) what does the file "points" stand for?

the file "points" include the coordinates of alle the points of the patch concerned. I use to obtain it by a paraview command (include sets, save data, .csv....).

Quote:

what do I have to specify in constant/boundaryData/throat/0 directory ?

you have to write the correct data (pressure in your case) for each point of the patch. If you don't have the datas on points, but on cells, this is not the correct BC to use.

Hope it has helped you a little.
Laurent

Lorenzo92 · October 12, 2016, 03:41

Thank you very much laurentD for your clear answer, it helps a lot.
To be sure I understood your explanation correctly: when you refer to point you don't think about cell's centroid, they are just the vertex point of a particular boundary face. Is this correct?

laurentD · November 18, 2016, 09:15

Sorry i haven't seen your answer.

Yes it refers to the vertex points related to the patch concerned. It is used by OF to associate a value (so the pressure in your case) with the correct position.

I'm not sure (maybe someone will read our conversation and confirm it) but i think that the word ...mapped... is used to indicate that the values are plotted on points instead of faces.

But what i'm sure is the signification of points ;-)

Have a good day.

L.

April 23, 2016, 04:17	problem with timeVaryingMappedFixedValue	#1
Lorenzo92 Member Lorenzo Join Date: Oct 2015 Location: Graz Posts: 49 Rep Power: 10	Hello everyone, I'm trying to solve a problem in which an inlet patch, called "throat", is defined. On this patch I would like to impose a time varying boundary condition on pressure, through timeVaryingMappedFixedValue. I followed the tutorial pitzDailyExptInlet but still I have doubts about the meaning of the files "points" ( under constant/boundaryData/Inlet) and the time directory "0" (under constant/boundaryData). In that case unstedy BC where on U field, here on pressure but that should not be an issue. So my questions are : 1) what does the file "points" stand for? ( maybe the location in terms of xyz coordinates of points , where time-varying BC is to be applied?) 2)what do I have to specify in constant/boundaryData/throat/0 directory ? ( I thought initially the value at different times of my pressure profile ) I'm rather new to this BC so presumably I am wrong in several points, any help would be very appreciated. Thanks

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October 12, 2016, 03:41		#3
Lorenzo92 Member Lorenzo Join Date: Oct 2015 Location: Graz Posts: 49 Rep Power: 10	Thank you very much laurentD for your clear answer, it helps a lot. To be sure I understood your explanation correctly: when you refer to point you don't think about cell's centroid, they are just the vertex point of a particular boundary face. Is this correct?

November 18, 2016, 09:15		#4
laurentD Senior Member Laurent DASTUGUE Join Date: May 2014 Location: Chartres, France Posts: 122 Rep Power: 11	Sorry i haven't seen your answer. Yes it refers to the vertex points related to the patch concerned. It is used by OF to associate a value (so the pressure in your case) with the correct position. I'm not sure (maybe someone will read our conversation and confirm it) but i think that the word ...mapped... is used to indicate that the values are plotted on points instead of faces. But what i'm sure is the signification of points ;-) Have a good day. L.