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

Vertical Axis Wind Turbine (VAWT) simulation

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   July 5, 2016, 22:15
Default Vertical Axis Wind Turbine (VAWT) simulation
  #1
New Member
 
Join Date: Jun 2016
Posts: 3
Rep Power: 6
Jorge22 is on a distinguished road
I have done a steady state simulation of a vertical axis wind turbine. The solution has converged to a max residual of 1e-5 but i get an excessive torque value so I'm having my doubts on the physics setup.

The steps i have followed are:

1.- Draw the wind turbine blades
2.- Draw a cylinder around the blades (rotating fluid)
3.- Draw a large frustum around the blades
4.- Substract the cylinder from the frustum to obtain the outer volume shown in the image.
5.- Subtract the blades from the cylinder to obtain the inner volume shown in the image.



* The cylinder containing the blades is set as a rotating domain with the design rotational speed of the turbine and Z rotation axis (turbine axis).
* The frustum is a stationary domain.

The boundary conditions i have used are:

- Inlet the left and lateral faces of the frustum, with a velocity component in the X axis (free stream of air).
- Outlet at the right face of the frustum.
- Interfaces between the frustum and cylinder common faces, with frozen rotor frame change
- Wall at the blades.

My questions are:
1.- Is the physics setup correct?

2.- The real torque in the turbine oscillates with time due to the angular rotation and different angles of attack. The torque obtained by CFX is the average over time?

3.- What is the physical effect of increasing the volume of the cylinder around the blades (with rotating fluid) ? It currently contains the blades tightly (cylinder height = 1.2x blade height)

Last edited by Jorge22; July 5, 2016 at 22:21. Reason: image upload
Jorge22 is offline   Reply With Quote

Old   July 5, 2016, 22:35
Default
  #2
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 16,539
Rep Power: 128
ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
Q1 - probably not. But you should do the first level of investigation yourself. Have a look in the post processor - do the streamlines look reasonable? Is the rotor rotating in the correct direction? Are you getting attached flow where you expect, and separations where you expect?

Q2 - If you modelled this as frozen rotor the torque returned is the instantaneous torque at this angle in the rotation.

Q3 - It should be no effect. If this has an effect it shows there is a problem in your setup.
ghorrocks is offline   Reply With Quote

Old   November 16, 2017, 07:44
Default jorge..how did you get an excessive torque value
  #3
New Member
 
Fenil Modi
Join Date: Sep 2017
Posts: 2
Rep Power: 0
fenil modi is on a distinguished road
i have followed same procedure which you have done.
i had make mesh in ICEM CFD 16.2 and run simulation in fluent 16.2 but i never got torque (moment) above 0.
i have give the rotating zone to frame motion and my aerofoils are stationary wall.
i have almost try all model like k-e (std and realizable), k-w(SST), S-A etc.

please any one give me some idea. why this is happening with me.
fenil modi is offline   Reply With Quote

Old   November 16, 2017, 17:22
Default
  #4
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 16,539
Rep Power: 128
ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
Try the fluent forum.
ghorrocks is offline   Reply With Quote

Old   November 17, 2017, 09:47
Default
  #5
New Member
 
Fenil Modi
Join Date: Sep 2017
Posts: 2
Rep Power: 0
fenil modi is on a distinguished road
hi ghorrocks;
thanks for your reply.but i dont know whats this fluent forum?
fenil modi is offline   Reply With Quote

Old   November 18, 2017, 06:18
Default
  #6
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 16,539
Rep Power: 128
ghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the roughghorrocks is a jewel in the rough
https://www.cfd-online.com/Forums/fluent/
ghorrocks is offline   Reply With Quote

Reply

Tags
vertical axis, wind turbine

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
High torque coefficient Cm for Vertical Axis Wind Turbine (VAWT) tony00 FLUENT 11 July 23, 2018 07:13
[ICEM] Boundary conditions in copy-rotate 3-bladed vertical axis wind turbine pollenhavy ANSYS Meshing & Geometry 2 February 17, 2017 18:01
CFD analysis on wind turbine rotor Ken (Wind Turbine CFD Super Rookie) Main CFD Forum 45 February 9, 2016 15:07
Airflow over Vertical Axis Wind TUrbine sthoms78 ANSYS 8 April 10, 2013 03:31
Vertical Axis Wind Turbine courtjester140 ANSYS 2 June 22, 2010 11:27


All times are GMT -4. The time now is 16:32.