Learning Forum

[Atif Ismail]

Dear Seniors, 
I am working on hydraulic fracturing simulation by coupling of Ansys fluent and transient structural. 
The work flow (2 way coupling) is: exporting the pore pressure data from ansys fluent to mechanical for the calculation of displacements and stresses (with change in fracture) and again exporting the results to ansys fluent. 
My goal is to study the fracture attributes on the basis of injected fluid pressure and other related parameters. 
Case: A cylinder with a hole in the center upto the 90% depth having a elliptical fracture at the bottom. 
I have some confusions, if you may assist.
1) Do I need to take the injection point at the borehole and fracture boundary as outlet in the fluent for this case (as shown in the below image)? 

2) Do I need to add any hydrostatic pressure in the ansys transient apart from the inlet and outlet pressure ranges in the fluent? 
3) Is this possible to run the hydraulic fracturing case without any pre-existing fracture? 
4) What should be the fixed support in this case (for the sample in the image)? As per my understanding, I am going to consider the top and bottom face of the cylinder as a fixed one. 

Thank you, 
Regards.

[Luca B.]

Hi, 

It is not totally clear to me how the application is? Do the fluids generate the fracture? Can you describe better the application?

Generally speaking you need to add hydrostatic pressure. By default it is not computed in Fluent so then you can export it to mechanical.

You can add fixed support on both top or bottom accoridng to your application

Luca

[Atif Ismail]

Thanks a lot for your reply Luca. 
I am working on hydraulic fracturing in which fractures and generated by injection of highly pressurized fluid. 
My goal is to export the porepressure information to transient mechanical for recalculation of the stresses and new displacments will be exported to fluent for remeshing. 
Since I was unable to find any mechanism that may help me to generate fracture at high pressure, so I considered the preexisting fractures as shown in the center of the cylindrical sample. 
How to visualize the considered preexisting fracture in the ansys fluent? 
Is this possible to create fractures in the model on the basis of pressurized fluid (with consideration of preexisting fractures)?
How to find the width and length of fracture for any specific injection pressure? 

Kindly if you may comment. 

Regards,

[Atif Ismail]

Hi Mr. Luca B.
I am trying to do the similar work done in the below mentioned link.
Numerical analysis of fluid-rock interactions in hydraulic fracturing (core.ac.uk)

if you may have a brief look. 
Regards,