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I wrote a UDF to return the maximum velocity within 2 inches of a specified surface.

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Old   September 21, 2022, 21:36
Default I wrote a UDF to return the maximum velocity within 2 inches of a specified surface.
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Chris N.
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I wrote a UDF to return the maximum velocity within 2 inches of a specified surface. To accomplish this, I defined a cell register to get all cells within 2 inches of that specified surface. I then used the register to separate out a new cell zone. The UDF loops over all cells within that new cell zone and returns the max velocity and cell centroid of where the max velocity occurs. I separated out the new cell zone for two reasons: 1) to reduce the number of cells to loop through and 2) to limit the cells to the surface of interest (ie, I wanted to exclude all other surfaces/walls other than the one I am interested in). Without separating out the cell zone, I would have had to loop over all cells in the entire domain and all face cells of the surface of interest to determine if the volume cell was within 2 inches.

I believe the above can be accomplished via expressions. However, I believe I can only return the maximum velocity within the cell register and not the location of that velocity using expressions.

Is there a way to accomplish the whole UDF (ie, find max velocity and location within 2 inches of desired surface) using expressions? Is there a better was to accomplish this via UDF? Is there a function that will calculate the distance between a face zone ID and cell or does that have to be programmed manually as described above (ie, looping over all cells and face cells)?

Can you give C_WALL_DIST(c,cell_thread) a face_thread instead of a cell_thread, where the face_thread would be the id a wall?
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Old   September 26, 2022, 01:30
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Alexander
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AlexanderZ will become famous soon enoughAlexanderZ will become famous soon enough
the way you explained your case makes me doubting you have working code,
show your code if you need help
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Old   September 26, 2022, 16:28
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AlexanderZ - The attached UDF code does work for my applications. Was just wondering if there was a better way.
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File Type: c getMaxVelocityAndLocation_v2.0.c (4.6 KB, 2 views)
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