[my101]

Hello Foamers,

I am doing a simulation for heat transfer in a CPU cooler using laplacianFoam. I want to calculate the integral of a field (e.g. gradTz) over a boundary/patch.

In OF-2.1.1, patchIntegrate utility <patchIntegrate -latestTime gradTz EXCHANGE_SURFACE> gives the output:

Time = 240
Area vector of patch EXCHANGE_SURFACE[0] = (-1.10854e-17 1.18664e-19 0.0013702)
Area magnitude of patch EXCHANGE_SURFACE[0] = 0.0188973
Reading volScalarField gradTz
Integral of gradTz over vector area of patch EXCHANGE_SURFACE[0] = (1.0814e-08 -7.43949e-08 -0.00792159)
Integral of gradTz over area magnitude of patch EXCHANGE_SURFACE[0] = -2.36515
End


In OF-6, patchIntegrate utility is replaced by a postProcess function <postProcess -latestTime -func 'patchIntegrate(name=EXCHANGE_SURFACE,gradTz)'> which gives the following output:

surfaceFieldValue patchIntegrate(name=EXCHANGE_SURFACE,gradTz):
total faces = 52131
total area = 0.0188973
Time = 240
Reading fields:
volScalarFields: gradTz
Executing functionObjects
surfaceFieldValue patchIntegrate(name=EXCHANGE_SURFACE,gradTz) write:
areaIntegrate(EXCHANGE_SURFACE) of gradTz = -2.36514
End


My queries are:
1) How can I get integral-over-vector-area (xValue yValue zValue) along with the magnitude in OF-6 as it shows in OF-2.1.1?
2) Integral-over-area magnitude is not the magnitude of integral-over-vector-area vector. What is the relation b/w integral over vector area and integral over area magnitude?

[rodrigo_barret0]

Hello,


I am having the same trouble. Did you find the solution?

[otaolafr]

Originally Posted by rodrigo_barret0

Hello,


I am having the same trouble. Did you find the solution?

hello, I am facing a similar issue (without the experience of using past versions)
I am using OF v7. and I can not succesfully achive to have integrate a field in a patch.... I have done a research in the forum and finish with this (averaged pressure over the boundary and this New Documentation: Field Function Objects) but I can not make them work, maybe because it is for 1912v? i dont know.... and I could not find any documentation in OF v7 to solve this...
have any of you succesfully done it?
I only want to extract the average T from a scalarTransport simulation for each time, and the mass flow average in inlet/outlet and pressure inlet at the last time in a simpleFoam simulation. I wanted to add them to the controlDict so they are all together in the same file . I have sepend at least two days looking only how to do this, without succes...
best regards

[HPE]

Hi

- Various functionalities do not exist within all the OpenFOAM variants. Therefore, one functionality may exist only in a single variant. Yet it is usually manageable to transfer them across. But the easiest solution is to install all variants at the same time.
- You can use `fieldAverage` FO on `T` to obtain time-averaged T?
- Or if you want to sample `T`, you can use various `sample` functionalities.
- To monitor the mass flow through given patches, you can use various functionalities. One can be surfaceFieldValue function object.

Hope this helps.

[otaolafr]

Originally Posted by HPE

Hi

- Various functionalities do not exist within all the OpenFOAM variants. Therefore, one functionality may exist only in a single variant. Yet it is usually manageable to transfer them across. But the easiest solution is to install all variants at the same time.
- You can use `fieldAverage` FO on `T` to obtain time-averaged T?
- Or if you want to sample `T`, you can use various `sample` functionalities.
- To monitor the mass flow through given patches, you can use various functionalities. One can be surfaceFieldValue function object.

Hope this helps.

hi HPE,
postProcess -latestTime -func 'patchIntegrate(name=inlet,p)' gived me the average as i was looking for, and also i can used with U but at least from my pre test it was not the correct answer as postProcess -latestTime -func 'patchIntegrate(name=inlet,U)' did not gave me the same value that i fixed in the inlet patch (was a fixed value in U file).
I assume that postProcess -func 'patchIntegrate(name=inlet,T)' and postProcess -func 'patchIntegrate(name=outlet,T)' will give me what i am looking for (average T at inlet and outlet, as i am trying to measure an RTD and not temperature...). but this is for post process so I can use it only in the stocked writenTimes, when if I could use it at the same time as the solver, i could stock only this average T in the inlet and oultet at all times even if I decide not to write the rest of the information.
And this https://www.openfoam.com/documentati...ieldValue.html was exactly what i was trying to do, i saw your original post, and find the field function, read it, but when i tried in V7. it didnot work, i found some surfacesFieldValue in etc folder, but it was quiet cryptic, and non information at all in the V7 guide user. sadly i need to develop in this version as we have a small server to run it and i can not install the other vr. but yes, surfaceFieldValue was exactly what i was trying to do....

[HPE]

Hi,

Can't you compile these function objects of OF1912 into OF7?

[otaolafr]

Originally Posted by HPE

Hi,

Can't you compile these function objects of OF1912 into OF7?

hello, just to clarify, I found the function objects in OF7 the issue is that the "writeControl" options are differents and OF7 does not recognize the options from 1912.

best regards, franco