November 1, 2017 at 7:03 pmomidFSISubscriber
I am simulating a simple flow over a cylinder with a circular domain shape in 3D with Fluent.
For continuity I am not getting a good convergence and the residual is close to 0.1 while I expect it to be much lower.
The drag coefficient is also not accurate especially for high Re. I have tried different RANS models , mesh is fine enough (O-type) though y+ getting from ANSYS is somehow high more than 100 which don't know why since my mesh is structured and very fine!
Transient solver with Time step~0.005-0.05 (s)
Any idea in this regard?
Thanks in advance!
November 2, 2017 at 8:28 amVishal GanoreAnsys Employee
How is your orientation of cylinder with respect to flow direction? Could you please show your geometry?
Are you doing similar to following tutorial but extending your domain to 3D? I would keep Y+ value close to 30 and use k-e standard wall function model.
November 2, 2017 at 5:10 pmomidFSISubscriber
Thanks for the reply!
I have a similar flow simulation where the cylinder is perpendicular to the fluid flow. The only difference is using circular fluid domain.
( diameter of cylinder, flow left to right, domain diameter:40D, domain depth=3D-5D)
My y+ as I calculated is good and around 5. I am using Spalart-Allmaras and SST- k-omega as later I wanna use these models for more complex geometry.
For high Re (like 88000) and domain depth of around 5D (D-diameter of cylinder), the values of drag coefficient I get is not accurate at all and for all the cases the continuity residual is around 0.1. My previous simulation for a coarser mesh or 2d case had really good result which I don't understand at all!
Any help is appreciated!
- You must be logged in to reply to this topic.
Earth Rescue – An Ansys Online Series
The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.
Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.
- Suppress Fluent to open with GUI while performing in journal file
- Floating point exception in Fluent
- What are the differences between CFX and Fluent?
- Heat transfer coefficient
- Getting graph and tabular data from result in workbench mechanical
- The solver failed with a non-zero exit code of : 2
- Difference between K-epsilon and K-omega Turbulence Model
- Time Step Size and Courant Number
- Mesh Interfaces in ANSYS FLUENT
- error in cfd post
© 2023 Copyright ANSYS, Inc. All rights reserved.