CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > Siemens > STAR-CCM+

High divergence in cfd-dem model

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By Cassian

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 24, 2022, 16:57
Default High divergence in cfd-dem model
  #1
New Member
 
Cassian
Join Date: May 2022
Posts: 5
Rep Power: 3
Cassian is on a distinguished road
I'm simulating fluid (water) flow through a packed dem particle bed in a cylindrical shaped domain.

When I set BCs to either a velocity inlet or stagnation inlet with very small velocity/ pressure values with a pressure outlet of 0 psi, I notice very high flow velocities and particle velocities with correspondingly high momentum divergence.
Even if I set a stagnation inlet of 0 psi pressure and pressure outlet of 0 psi (no gravity), instead of having no fluid flow (0 velocity), I end up with super high velocities and divergence.

I'm using Coupled flow model with the Implicit unsteady solver. Flow is of constant density.
I've not found any improvements by using the Segregated flow model.
I have Two-Way coupling for Lagrangian models turned on.
My timestep is 1e-7.

I've attached screenshots of what happens during my runs, if anyone has any suggestions or insights, I would be super grateful.
Attached Images
File Type: png forum3.PNG (77.4 KB, 3 views)
File Type: png forum4.PNG (38.3 KB, 12 views)
File Type: png forum1.png (28.0 KB, 10 views)
File Type: png forum2.PNG (151.6 KB, 7 views)
File Type: jpg forum5.jpg (62.4 KB, 6 views)
Mahmoud Abbaszadeh likes this.

Last edited by Cassian; June 24, 2022 at 17:13. Reason: Adding important information
Cassian is offline   Reply With Quote

Old   March 1, 2023, 10:08
Default
  #2
Member
 
Mahmoud
Join Date: Nov 2020
Location: United Kingdom
Posts: 43
Rep Power: 5
Mahmoud Abbaszadeh is on a distinguished road
Hi Cassian,

Hope you are doing well.
I wonder if you can share with us the details of your simulation. I am currently simulating something similar. I want to create a packed bed and run water flow through it.

Best Regards,
Mahmoud
Mahmoud Abbaszadeh is offline   Reply With Quote

Reply

Tags
cfd-dem, divergence issues, starccm+


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Divergence detected in AMG solver. VOF. Mr.Mister Fluent Multiphase 4 September 25, 2023 07:10
Fail to converge when solving with a fabricated solution zizhou FLUENT 0 March 22, 2021 06:33
Two Phase Flow In Vertical Pipe stonepreston FLUENT 2 October 31, 2017 08:35
Dry cooler - simplified cfd model mech_01 FLUENT 0 September 23, 2017 15:00
Where do we go from here? CFD in 2001 John C. Chien Main CFD Forum 36 January 24, 2001 21:10


All times are GMT -4. The time now is 10:42.