About rho fluid on Steady Rel_perm about mplbm-ut

[je-santos]

That is interesting. Could you check the resulting fluid configurations and check if there's anything weird going on?
Visualizing them with paraview is probably the easiest way.

[azzahrapajaaa]

i use synthetic 3D single fracture as my Geometry. I already check the geometry input in the output file (tmp), from the vtkgeometry.vti 2_phase_sim, the geometry is correct and there is nothing strange. But when calculating the relative, the geometry becomes strange, seen from PorousMedium.vti in the "relperm/4relperm" folder. I assume there was an error while forming the geometry for running relative permeability. But i still don't have any clue where and how to fix it. Thank you

[je-santos]

Can you plot density ?

[azzahrapajaaa]

i try to visualize the density from The rho_f1_000_iteration.vti in each domain. Here's the result between domain 1 and the last domain , there's no siginificant differences only the red color getting bold and more obvious. My geometry has 11 domain and all the simulation 2_phase are converge at the same iteration, 4000, only domain 8 and 9 at iteration 5000. Could that be the cause of the problem I'm having?

[je-santos]

That looks wrong. It seems that all the domain is saturated.

I just re-read your initial question. The density parameter should not be changed. The prescribed density is for numerical stability, and it's not representative of the fluid properties.

The density does not play a role in viscous flows unless there is gravity.

[azzahrapajaaa]

Ohh i see, at first i thought it's Multiphase flow simulation so i can change the density of fluid to vary it. Thank you very much for your answer, it helps me a lot.

[je-santos]

Don't worry about the density, the viscosity is the one that has a strong impact. Beware that the model used here (Shan-Chen) is notoriously unstable at high viscosity ratios.

[azzahrapajaaa]

can i ask again?

[azzahrapajaaa]

how to set the viscosity in the code?

[je-santos]

Move omega_f1 and omega_f2 slowly away from 1

[azzahrapajaaa]

Okayyy Thank You:)

[dreamofzhouxin]

i use synthetic 3D single fracture as my Geometry. I already check the geometry input in the output file (tmp), from the vtkgeometry.vti 2_phase_sim, the geometry is correct and there is nothing strange. But when calculating the relative, the geometry becomes strange, seen from PorousMedium.vti in the "relperm/4relperm" folder. I assume there was an error while forming the geometry for running relative permeability. But i still don't have any clue where and how to fix it. Thank you

hi azzahrapajaaa:

 I am new to LBM simulation, and I also want to simulate two phase flow in single rock fracture. I tried the useful code written by je-santos like you, but I don't know how to input a 3D fracture geometry that is in the folder (/domain_construction/fractures/). Yes, I have gotten fracture_Df_2*.dat file int the output folder by Create_rough_fractures.m code, can i input it to the simulation directly or how can i input my fracture geometry like Df_25.fre?  Please give me some advises, thanks a lot in advance, waiting for your reply!

zhouxin

[azzahrapajaaa]

@dreamofzhouxin Hi zhouxin. I'm sorry but the geometries was generated by other code. I only use je-santos code for the LBM two phase flow simulation. I don't know what is the certain type of your output file, but you can save your geometry as .raw file and upload it on google drive, and copy the download link to the code.