Particle tracking unstable

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dionvandeijl
Posts: 2
Joined: Wed Jun 19, 2019 9:09 am
Location: Netherlands

Particle tracking unstable

Post by dionvandeijl » Wed Jun 19, 2019 12:50 pm

I have two questions concerning particle tracking in hydrus 3.01.1490.
Q1
I have a model where the water flow simulation is stable. However, when I add some particles in the domain the model crashes without any error notification. Only on some specific locations the model can solve the problem without crashing. I have enclosed two models, one with particles on locations which the model can handle and one model where the particles are located on locations where the model crashes.
I have tried:
• Refine the grid in the whole domain
• Decrease the initial time step
• Locate the particles on the mesh and not on the geometry
• Change the soil parameters to a uniform soil profile
Q2
I think that there is a bug in the conversion of the particle.out file to ASCII. When I have a model where particle tracking works and I export the particle.out to ASCII the ASCII file only shows data of one particle copied in all columns (in this case I used more than 5 particles and the paths are correctly displayed in the user interface for each print time). The values of column 2 and 3 are equal to column 4 and 5, 6 and 7, etc.
Attachments
ascii.png
ASCII conversion particle.out
ascii.png (23.27 KiB) Viewed 248 times
Hydrus_particle_OK.zip
(587.05 KiB) Downloaded 14 times
Hydrus_Particle_Error.zip
(318.6 KiB) Downloaded 18 times

Mirek
Posts: 408
Joined: Sat Mar 16, 2002 4:00 pm
Location: Czech Republic
Contact:

Re: Particle tracking unstable

Post by Mirek » Wed Jun 19, 2019 1:15 pm

We will have a look at the mentioned issues, just two questions:
A/ Do you use the standard solver or HYPAR?
B/ Do you use 32-bit or 64-bit version?
Thanks M.

dionvandeijl
Posts: 2
Joined: Wed Jun 19, 2019 9:09 am
Location: Netherlands

Re: Particle tracking unstable

Post by dionvandeijl » Wed Jun 19, 2019 1:24 pm

Okay thank you,
I run a 64bit version with the normal solver
Hydrus.png
Hydrus.png (69.39 KiB) Viewed 244 times

Jirka
Posts: 4760
Joined: Sat Mar 16, 2002 3:47 pm
Location: USA
Location: Riverside, CA

Re: Particle tracking unstable

Post by Jirka » Wed Jun 19, 2019 3:19 pm

The particle tracking algorithm fails because of the initial location of particles near the vicinity of the drain with extremely small elements (which abruptly change into large elements). When I deleted particles 47 and 48, the problem ran quite well. J.

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