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-   -   Porous media properties - waterground modeling (https://www.cfd-online.com/Forums/fluent/187892-porous-media-properties-waterground-modeling.html)

michal.s May 17, 2017 15:26

Porous media properties - waterground modeling
 
Hello there!

I am modeling a geothermal well at depth around 2km and the soil around.
The zone, where the ground is should be set as porous media and the water should be drained through the well.
I have a problem because I have no idea how to find values for viscous resistance and inertial resistance.
a) In papers I've found permeability for the soil which is 10e-15 m^2 so viscous resistance is 10e15 m^-2
b) According Fluent User Guide I've found a way how to calculate those values for packed bed based on average diameter of particle and porosity.
As the porosity is known - 0.1. The only problem is inertial resistance.

Questions:
a) Am I right about that values? Is viscous resistance = 1/permeability ?
b) Can I apply that approximation (for packed bed) And can I calculate avarage diameter of particle using formula for alpha (according to User Guide) which is alpha= (Dp^2*eps^2)/(150*(1-eps^2))

I am not familiar in geology and porous media problem, so I am a little bit confused.

I also tried to find problems like that here but It looks like it is the first time.

I would appriciate your comments on that.

Thank you!

Kushal Puri May 18, 2017 05:26

You are correct about the your viscous resistance that
viscous resistance = 1/permeability

but you cant directly find the inertial resistance from here, if you have pressure drop data then we can easily find this.

michal.s May 18, 2017 06:37

1 Attachment(s)
The only data I got about pressure is that Figure 4.
But I'm afraid it's just about conditions for specific depth, not about pressure drop due to fluid flow through the porous media

From the other hand those values were changing during well operation - so because of the water flow through the ground.

Thank you!


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