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UDF not applied at specified location

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Old   August 4, 2023, 18:05
Default UDF not applied at specified location
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Hello,

I am applying a source of mass and momentum near a wall in a FLUENT simulation. The point I am specifying as the mean of the gaussian is within the first cell from the wall, shown as the circular point in the figure. The gaussian however is being centered around a point that is a distance off the wall. I am using the transition SST model which doesnt have wall functions. I have also tested the logic of having a gaussian sitting at/near the wall on a simple square domain (image include). In the case of the square domain the gaussian is able to sit at the wall but when applied to a curved wall the gaussian is some distance away from the wall. I have even tried forcing the mean of the gaussian to be outside of the domain (inside the wall) and the gaussian is still being forced some distance away from the wall! Why does the gaussian not want to sit on the curved wall when it is able to on a flat wall?
Gaussian_on_wall.jpg

Gaussian_in_wall.jpg

Gaussian_on_wall_simple.jpg
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Old   August 6, 2023, 11:36
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I am guessing, it must be about how you calculate from cell-centroid or the first cell distance from the wall.
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Old   August 7, 2023, 19:06
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I am calculating from cell centroid, I have made it so the desired mean of the gaussian sits in the first cell from the wall. When applied on a trivial flat plate it works as intended. The mean is at the specified point, however, on a curved surface the mean is no longer at the specified point. Even when the desired mean of the gaussian is moved outside of the domain, the source is still appearing some distance off the surface (as shown in the figures on the original post).

The code for it is relatively simple, I can attach it if desired, the jist of the code is to go through all the cell centroids and apply a source based on a gaussian distribution.

Im not sure if that helps clarify anything. This problem is something I have approached others about and we are all stumped on the behavior we are seeing.
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