Learning Forum

[mohammedlaminemekhalfia]

Dear Ansys users.

I hope that this post will find you well.

well I am working on one way fsi problem and I would like to know please.

How to set the data transfer in system coupling

[Stephen Orlando]

Are you wanting to transfer displacement from Mechanical to Fluent, or pressure force from Fluent to Mechanical.
If you want to transfer displacement from Mechanical to Fluent, you'll only need the data transfer shown in the second image.
If you want to transfer pressure force from Fluent to Mechanical it would be better to use a direct connection and not use System Coupling:

[mohammedlaminemekhalfia]

Thanks steve, I am using ANSYS 2021 and the transfer of solution tab to setup can not be performed, I tried several time

[UniversityofQLD]

Are you using Workbench or stand-alone systems? What systems are you using? You would usually use ANSYS Mechanical and CFX or Fluent. Define a System Coupling region in Mechanical (usually a surface) and allow for mesh motion via System Coupling in your fluid solver. You can then create the data transfer in System Coupling.

[mohammedlaminemekhalfia]

Thanks so much for your feedback it was really very very helpfull and I could find the solution to run the SC to resolve the problem
yet I tried two way FSI, to plot displacement of this blade tip per time.
The Fluent has a transient pressure inlet with a step function where at 0.3 s I used Static structural.
the step time was 0.001, the full time was 2 s and the relaxation factor =0.55 for both side.
I used Ensight to visualize the results
I have two questions:
I expected that the result (picture below) should be a step function not a ramp in the interval between 0.3 and 0.9 ? what would be the reason for that? I performed one way FSI using external data transfer and it seem that the feedback was a step function so why there is this divergence in results between the two methods?
How to make System coupling GUI work with more than 2 solvers? it is so so low and I need it faster to run for different Pressure inlet functions

[UniversityofQLD]

@Mohammedlamine
Where are you measuring your pressure? If you impose a step function at the inlet, areas downstream need to build up to that pressure over time so you will see a ramp. Can you post pictures of your inlet condition, your measurement and where you measure it?

You can increase processing speed by changing your solver settings in Mechanical and Fluent. In Mechanical, select "Analysis Settings" and set number of cores to the desired number. In Fluent, select "Processing Options: Parallel" and input the number of cores. You can set them both to the maximum number of cores you have available. This depends on your machine and how many cores your license allows.

[mohammedlaminemekhalfia]

Thanks again for the feedback.
for the pressure, I am measuring the pressure at the boundary (Blade surface) and the Inlet, The pressure evolution shows a step function.
My inlet function is shown in the below picture.
The Domain is as follows: The inlet is the pipe Inlet



For the Displacement, I am measuring that on the Blade tip. and this was the problem why the result is showing a ramp at the top
for the Solvers, I already changed the number of cores in both mechanical and fluent, I have enough licenses, yet when I launch the simulation using system coupling GUI, it works only with 2 solvers from fluent and mechanical. ( I checked the Licence monitoring and I changed several core numbers yet the problem remains).