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

Wind turbine torque calculation is less than expected

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 20, 2015, 08:21
Unhappy Wind turbine torque calculation is less than expected
  #1
New Member
 
Ahmed
Join Date: Dec 2014
Posts: 2
Rep Power: 0
AhmedMaklid is on a distinguished road
Hi !! help is needed
I am simulating a HAWT but the tesults seems to deviate from the experimental results ( Torque and drag are the main focus of my study)

The case is as follows
Velocity inlet, Pressure outlet
the control volume consists of three zones upper-stream, Moving Zone and Down-stream
V=-10 m/s in the x direction
Moving Zone is MRF around x axis X=1 , Y=0, Z=0 and
w= -133 rad/s which corresponds to the optimum tip speed ratio of 6.
turbine blade wall moving 0 rad/s with relative to adjacent zone
CFD algorithm SIMPLE (default option)
Turbulent model K-epsilon standard near wall function
Interpolating scheme for the first 10 iteration 1st order upwind were used then for 1000 iteration followed 2nd order were used
Pressure (Standard)
Density (Second Order Upwind)
Momentum (Second Order Upwind)
Modified Turbulent Viscosity (Second Order Upwind)
can anyone tells me why the torque value is very low its 13 N.M while in real case its around 85 N.M
Attached Images
File Type: jpg FFF 5.jpg (27.2 KB, 36 views)
File Type: jpg streamlines.jpg (36.3 KB, 39 views)
File Type: jpg case.jpg (25.8 KB, 35 views)
File Type: jpg case2.jpg (24.2 KB, 30 views)
File Type: jpg casesetup.jpg (59.0 KB, 33 views)
AhmedMaklid is offline   Reply With Quote

Old   February 20, 2015, 14:56
Default
  #2
New Member
 
Ahmed
Join Date: Dec 2014
Posts: 2
Rep Power: 0
AhmedMaklid is on a distinguished road
I did something that seems to enhance the torque but it is still lower than expected what i did is as described in the thread (Impact of pressure on the blades with MRF?) @maverick90 which i recommend you to read its very helpful i the case as @ghost82 stated to set the walls of the zones as absolute with 0 rad/s but he also stated to take into account the boundary condition at the inlet which i think is the problem here because when i set the velocity to be normal to boundary condition it gives me components value in all direction in x, y, z
that`s why i choose the velocity in absolute in x-components to be 10 m/sec i don`t whats wrong but when i computed the maximum velocity from the gradient and it reached only 3.6 m/sec.
can anyone tells me what to do to solve this problem.

Attached Images
File Type: jpg trial withno interfaces.jpg (38.0 KB, 21 views)
File Type: jpg blade.jpg (26.3 KB, 12 views)
AhmedMaklid is offline   Reply With Quote

Reply

Tags
case set-up, drag force, hawt wind turbine, mrf. moving wall, torque


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
error compiling modified applications yvyan OpenFOAM Programming & Development 21 March 1, 2016 04:53
CFD analysis on wind turbine rotor Ken (Wind Turbine CFD Super Rookie) Main CFD Forum 45 February 9, 2016 14:07
Torque calculation of 2D VAWT Wind Turbine Anonymized_JL1 FLUENT 14 September 26, 2013 03:35
how to find wind turbine torque from CFD ? siripon Main CFD Forum 1 August 27, 2012 00:41
ParaView for OF-1.6-ext Chrisi1984 OpenFOAM Installation 0 December 31, 2010 06:42


All times are GMT -4. The time now is 05:50.