CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Torque of Savonius turbine is not convergent

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 4, 2012, 22:16
Default Torque of Savonius turbine is not convergent
  #1
Member
 
le
Join Date: Nov 2009
Location: seoul
Posts: 34
Rep Power: 16
fsifsi is on a distinguished road
Dear all,
I used Fluent 13 to simulate the Savonius turbine with obstacles was placed front of it as attached picture. k-w sst turbulence model and the second order discretisation were selected. However, I could not get convergence with time for Torque of turbine (Cm) while Cm is well convergent with time for the case of without obstacles.
Could you give me some advice, please.
Thanks.
Attached Images
File Type: jpg CM.jpg (72.9 KB, 50 views)
File Type: jpg MESH.jpg (56.7 KB, 55 views)
fsifsi is offline   Reply With Quote

Old   September 5, 2012, 04:04
Default
  #2
Member
 
Join Date: Mar 2009
Posts: 85
Rep Power: 17
husker is on a distinguished road
Hi,

Flow is unsteady, so Cm is supposed to be unsteady. You have to consider other scalars to judge convergence. Then you will have an idea about how Cm oscillates.

Regards,
husker is offline   Reply With Quote

Old   September 6, 2012, 01:29
Default
  #3
Member
 
le
Join Date: Nov 2009
Location: seoul
Posts: 34
Rep Power: 16
fsifsi is on a distinguished road
Thanks,
Yes, the flow is unsteady so Cm should be oscillated, however, it should be repeated over one cycle or periodic of time.
fsifsi is offline   Reply With Quote

Old   December 6, 2012, 07:22
Default
  #4
Senior Member
 
Andrea
Join Date: Feb 2012
Location: Leeds, UK
Posts: 179
Rep Power: 16
Andrea1984 is on a distinguished road
Hi fsifsi,

can I ask you how do you evaluate the turbine torque? Do you use the Cm value or the Momentum obtained from Result Reports?

Thanks,

Andrea
Andrea1984 is offline   Reply With Quote

Old   June 23, 2013, 21:52
Default
  #5
Member
 
le
Join Date: Nov 2009
Location: seoul
Posts: 34
Rep Power: 16
fsifsi is on a distinguished road
I used Cm value
fsifsi is offline   Reply With Quote

Old   June 24, 2013, 09:50
Default
  #6
Far
Super Moderator
 
Sijal
Join Date: Mar 2009
Location: Islamabad
Posts: 4,553
Blog Entries: 6
Rep Power: 54
Far has a spectacular aura aboutFar has a spectacular aura about
Send a message via Skype™ to Far
Lower the time step. how did you calculate the time step?
Far is offline   Reply With Quote

Reply

Tags
force monitor, savonius, torque

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Problem with torque output from a turbine simulation. pa-dundas FLUENT 5 July 17, 2022 06:27
Difficulty in calculating angular velocity of Savonius turbine simulation alfaruk CFX 14 March 17, 2017 07:08
Torque calculation of 2D VAWT Wind Turbine Anonymized_JL1 FLUENT 14 September 26, 2013 04:35
Turbulent dissipation rate effect turbine torque?? sedongjjang FLUENT 0 August 24, 2012 15:13
Turbulent dissipation rate effect turbine torque?? sedongjjang FLUENT 0 August 24, 2012 15:12


All times are GMT -4. The time now is 14:05.