Hello,
I am working on a simulation of a pipe with shrinkage and I am really having a problem to get good results. I’ve tried several mesh configurations and I’ve changed the numerical settings but none of these tries worked. The pipe has the following dimensions:
Diameter 1: 40 mm; Diameter 2: 20mm; Length of the 1st section: 1000 mm; Length of the 2nd section: 500 mm. Total length: 1500 mm.
This is the link of my last simulation try:
Someone would have a solution or a tip to help me solving this problem? Do you think the sharp corners/edges would be an issue?
I thank you for your attention!
All the best!
Hi @bertrand,
have you had a look at the shrink fit analysis by my colleague @ahmedhussain18? You can use this as an inspiration.
Shrink Fit Analysis of Tool Holder
Let me know if that helps.
Best,
Jousef
Hi @jousefm,
Thank you for your answer.
I think I cannot use your colleague simulation as an inspiration because it is a FEA analysis and in my case it is a CFD simulation.
Hi @bertrand,
thanks for pointing this out. Did not have a look at the project you posted. Will have a look at it as soon as I have time and come back to you.
Could you explain what kind of result you would expect from the simulation as you are talking about “good results”.
Cheers!
Jousef
Hi @jousefm ,
When I say “good results” I would like to say coherent to reality. The velocity and pressure field that I have got as answer are clearly false. In the velocity fields, for example, one cannot see the fluid recirculation zones; The pressure fields are almost constants (Almost all the results are constants according to the field charts). I expect to see at least a pressure drop due to losses between the inlet and the outlet of the fluid domain.
The residuals charts do not descend to at least 10^-4 as well, but for that I need to check the convergence criteria of this solver.
Thank you very much for you attention!
All the best
Hi @bertrand,
I get you now. Let me check that out as soon as I have time. Feel free to try some adaptions in the boundary conditions if you have time. If you do not want to use own core hours you can contact me and I can run the simulations for you. No worries about that!
Cheers and all the best!
Jousef
OK @jousefm, thank you very much!
Best wishes!
Sorry for the small delay @bertrand!
Some things I would recommend to you:
1. Could you try using the standard wall boundary condition and not the customizable one?
2. The simulation has to run for a longer period of time - only 20 timesteps are performed in your simulation. An incompressible flow case requires something more than approx. 200 to get to steady-state. An ideal number will be 1000 to 2000.
See if these changes have a significant impact on your simulation and let me know how things go!
Good luck!
Jousef