sampleDict: automatically sample all neighboring cells of a line

Knusper · January 31, 2017, 08:10

Dear OpenFoamers,

I want to sample data around an axis using sampleDict.

In order to get values of cells that are actually intersected by the axis (see illustration below), I can just use the keyword "midPoint", which requires the axis and then chooses the cells accordingly.

Now, what is the easiest way to also get the values in the neighboring cells of that axis, in order to compute finite differences?

Unfortunately, my grid has several refinement levels, which is why I cannot just specify 3 different axes. It would be a lot of work to manually specify all points where samples should be written. However, my axis points straight into z-direction, which could make it easy.

Is there a way to get these values automatically using uniform, face, midPoint, midPointAndFace etc. or will I have to edit the code of libsampling.so and write it myself?

Knusper · March 16, 2017, 09:19

Since a quick solution is not in sight and I did not want to dive in too deep into the C++ code, I have specified every single point that needs to be sampled individually. This was done by a script in bash that outputs a textfile with all sample locations.

January 31, 2017, 08:10	sampleDict: automatically sample all neighboring cells of a line	#1
Knusper New Member Michael Hoss Join Date: Sep 2016 Posts: 8 Rep Power: 9	Dear OpenFoamers, I want to sample data around an axis using sampleDict. In order to get values of cells that are actually intersected by the axis (see illustration below), I can just use the keyword "midPoint", which requires the axis and then chooses the cells accordingly. Now, what is the easiest way to also get the values in the neighboring cells of that axis, in order to compute finite differences? Unfortunately, my grid has several refinement levels, which is why I cannot just specify 3 different axes. It would be a lot of work to manually specify all points where samples should be written. However, my axis points straight into z-direction, which could make it easy. Is there a way to get these values automatically using uniform, face, midPoint, midPointAndFace etc. or will I have to edit the code of libsampling.so and write it myself?

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March 16, 2017, 09:19		#2
Knusper New Member Michael Hoss Join Date: Sep 2016 Posts: 8 Rep Power: 9	Since a quick solution is not in sight and I did not want to dive in too deep into the C++ code, I have specified every single point that needs to be sampled individually. This was done by a script in bash that outputs a textfile with all sample locations.