|
[Sponsors] |
November 21, 2023, 06:23 |
How to make my simulation converge?
|
#1 |
New Member
Join Date: Nov 2023
Posts: 3
Rep Power: 3 |
Hello everyone,
I'm a master's student and relatively new to Ansys Fluent. Since September, I have been learning how to use it from scratch by myself. I'm writing this post because I'm struggling to let my simulation for an abrupt expansion pipe converge. The geometry of my abrupt expansion pipe is like this: abrupt expansion pipe.png Mesh qualities: - Minimum Orthogonal Quality: 0.16 - Maximum skewness: 0.39 (According to the manual, these qualities seem to be okay, though it's not that good.) The setup in Fluent that I did is the following: Solver setting in General: - Type: Pressure-Based - Velocity Formulation: Absolute - Time: Steady Since the flow is laminar(Re for the thin pipe = 2000, Re for the thick pipe = 666), I choose the Laminar model. Boundary conditions: - Inlet velocity = 0.172 m/s - Outlet pressure: Gauge pressure = 0 Pa When I set smaller inlet velocity (0.001 m/s, 0.003 m/s, 0.005 m/s, 0.011 m/s, 0.021 m/s, 0.043 m/s), the simulation successfully converged. However, with a larger inlet velocity like this time (0.172 m/s), the simulation no longer converges... I tried the following solutions, but none worked well: - Increase the number of iterations - Change fluid time scale - Change relaxation factors I have been trying my best to think about possible solutions by myself, but unfortunately, I have not succeeded. I would appreciate it if some of you could give me possible suggestions. |
|
November 21, 2023, 16:11 |
|
#2 |
Senior Member
Lorenzo Galieti
Join Date: Mar 2018
Posts: 375
Rep Power: 12 |
Do you have flow separation when the pipe area increases?
|
|
November 21, 2023, 22:41 |
|
#3 |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34 |
get converged solution for 0.043 case
don't reinitialize, increase inlet speed and run simulation again increase inlet speed gradually
__________________
best regards ****************************** press LIKE if this message was helpful |
|
November 27, 2023, 12:18 |
|
#4 |
New Member
Join Date: Nov 2023
Posts: 3
Rep Power: 3 |
Hi LoGal,
Some eddies were observed. I did meshing again and then my simulation successfully converged. Anyway, I really appreciate that you kindly gave me a prompt reply. Thank you for your help. Best regards, Hanako |
|
November 27, 2023, 12:23 |
|
#5 |
New Member
Join Date: Nov 2023
Posts: 3
Rep Power: 3 |
Hi AlexanderZ,
Thank you very much for your suggestion. After re-meshing, my simulation successfully converged. But I'll try your suggestion later as well for my learning. Best regards, Hanako |
|
Tags |
converge case setup, converge error, laminar, laminar flow in pipe |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
somaFoam - And plasma goes weee | Destouches | OpenFOAM Running, Solving & CFD | 11 | July 17, 2024 07:55 |
[blastFoam] BlastFoam Question | alimea | OpenFOAM Community Contributions | 17 | January 28, 2023 11:50 |
Help to make LES simulation faster | Pj. | OpenFOAM Running, Solving & CFD | 14 | December 10, 2019 05:13 |
[waves2Foam] Waves2Foam Related Topics | ngj | OpenFOAM Community Contributions | 660 | August 20, 2018 13:39 |
OpenFOAM with IBM AIX | matthias | OpenFOAM Installation | 20 | March 25, 2008 03:36 |