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yjhp1016 / taichi_LBM3D

A 3D sparse LBM solver implemented using Taichi
MIT License
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The Velocity is similar to the theory, but the permeability is far from the theory of the single phase. #29

Open xiangWu-WW opened 1 month ago

xiangWu-WW commented 1 month ago
39570dc3f729281517d01fd665536c0 eaaf639a75b60a029cb15997047dba2 ef6d4732ccdd544fc0dc17685a1a143

Hi, Dr. yang，I build a fracture(width=12px) to valid the poiseuille flow with the condition in your code, the fy = 1e-4 and niu = 1/6 . The result suggest that the Velocity is similar to the theory (I modified the coordinate), but the permeability is far from the theory (12*12/12=12),I wonder how to fix it. Thanks a lot!

xiangWu-WW commented 1 month ago

After increasing the number of iterations, the permeability increases, but it is also larger than the theoretical value and has a trend of increasing.

6b2bc91adad9e3ab01ae753f26d694c
yjhp1016 commented 1 month ago

It looks like the simulation doesn't reach equilibrium... You probably need to make the simulation longer, or use a larger viscosity which will help to reduce the iterations required to reach equilibrium...

On Tue, 23 Jul 2024 at 15:32, xiangWu-WW @.***> wrote:

After increasing the number of iterations, the permeability increases, but it is also larger than the theoretical value and has a trend of increasing. 6b2bc91adad9e3ab01ae753f26d694c.png (view on web) https://github.com/user-attachments/assets/8a1462c3-ca84-40a2-8f36-798557259cf0

— Reply to this email directly, view it on GitHub https://github.com/yjhp1016/taichi_LBM3D/issues/29#issuecomment-2245421046, or unsubscribe https://github.com/notifications/unsubscribe-auth/AJEDKQALW76NLK5WA7G4WZ3ZNZSOFAVCNFSM6AAAAABLKRMJ7GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENBVGQZDCMBUGY . You are receiving this because you are subscribed to this thread.Message ID: @.***>

xiangWu-WW commented 1 month ago

It looks like the simulation doesn't reach equilibrium... You probably need to make the simulation longer, or use a larger viscosity which will help to reduce the iterations required to reach equilibrium... … On Tue, 23 Jul 2024 at 15:32, xiangWu-WW @.> wrote: After increasing the number of iterations, the permeability increases, but it is also larger than the theoretical value and has a trend of increasing. 6b2bc91adad9e3ab01ae753f26d694c.png (view on web) https://github.com/user-attachments/assets/8a1462c3-ca84-40a2-8f36-798557259cf0 — Reply to this email directly, view it on GitHub <#29 (comment)>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AJEDKQALW76NLK5WA7G4WZ3ZNZSOFAVCNFSM6AAAAABLKRMJ7GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENBVGQZDCMBUGY . You are receiving this because you are subscribed to this thread.Message ID: @.>

Thank you for your timely reply. After increasing the number of iterations and modifying the viscosity, the permeability still does not converge and tends to continue to increase. Is this a problem of boundary conditions? But the most puzzling part is that the velocity seems to be consistent with the theory.

yjhp1016 commented 1 month ago

You might need to go into the code to check if there is some bug in permeability/velocity calculation. This is an open source project, all kinds of help are welcomed!

On Wed, 24 Jul 2024 at 02:46, xiangWu-WW @.***> wrote:

It looks like the simulation doesn't reach equilibrium... You probably need to make the simulation longer, or use a larger viscosity which will help to reduce the iterations required to reach equilibrium... … <#m1604760991681197934> On Tue, 23 Jul 2024 at 15:32, xiangWu-WW @.> wrote: After increasing the number of iterations, the permeability increases, but it is also larger than the theoretical value and has a trend of increasing. 6b2bc91adad9e3ab01ae753f26d694c.png (view on web) https://github.com/user-attachments/assets/8a1462c3-ca84-40a2-8f36-798557259cf0 https://github.com/user-attachments/assets/8a1462c3-ca84-40a2-8f36-798557259cf0 — Reply to this email directly, view it on GitHub <#29 (comment) https://github.com/yjhp1016/taichi_LBM3D/issues/29#issuecomment-2245421046>, or unsubscribe https://github.com/notifications/unsubscribe-auth/AJEDKQALW76NLK5WA7G4WZ3ZNZSOFAVCNFSM6AAAAABLKRMJ7GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENBVGQZDCMBUGY https://github.com/notifications/unsubscribe-auth/AJEDKQALW76NLK5WA7G4WZ3ZNZSOFAVCNFSM6AAAAABLKRMJ7GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENBVGQZDCMBUGY . You are receiving this because you are subscribed to this thread.Message ID: @.>

Thank you for your timely reply. After increasing the number of iterations and modifying the viscosity, the permeability still does not converge and tends to continue to increase. Is this a problem of boundary conditions? But the most puzzling part is that the velocity seems to be consistent with the theory.

— Reply to this email directly, view it on GitHub https://github.com/yjhp1016/taichi_LBM3D/issues/29#issuecomment-2246701969, or unsubscribe https://github.com/notifications/unsubscribe-auth/AJEDKQBXIUD5JM4QFEICQCDZN4BQXAVCNFSM6AAAAABLKRMJ7GVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZDENBWG4YDCOJWHE . You are receiving this because you commented.Message ID: @.***>