[sabaeieng]

Hi all.
I want to simulate a vertical axis wind turbine in FLUENT6.3 but I have some problems about that.(I'm a rookie in CFD)
Could you please tell me: 1- How should I calculate power coefficient (cp) of turbine in fluent?????
2- I want to do my calculations while the turbine rotates, so in boundary conditions I chose a number(for example 26 rad/s) as a rotational speed for my blades, is this a proper method????
I must mention that my simulation is 2d and I use k-e method.
I would like to know if anyone has worked in a similar project and can help me now?
Thanks for your reply.

[CFDtoy]

Hi,
2D runs with sliding mesh or MRF methods are pretty straightforward with FLUENT and the results are pretty good - computing force effects, pressure coefficient, predicting wakes (velocity deficit) etc.

1.Once you complete the run - go to reporting results and take a surface and view pressure coefficient.
2. For the Bound cond..yes, this value goes into the rotating reference velocity

I will be posting some snapshots in my blog.

Regards,

CFDtoy

Originally Posted by sabaeieng

Hi all.
I want to simulate a vertical axis wind turbine in FLUENT6.3 but I have some problems about that.(I'm a rookie in CFD)
Could you please tell me: 1- How should I calculate power coefficient (cp) of turbine in fluent?????
2- I want to do my calculations while the turbine rotates, so in boundary conditions I chose a number(for example 26 rad/s) as a rotational speed for my blades, is this a proper method????
I must mention that my simulation is 2d and I use k-e method.
I would like to know if anyone has worked in a similar project and can help me now?
Thanks for your reply.

[sabaeieng]

Thank you very much CFDtoy, I gave the answer of my questions from your post but still I have some doubts about calculation of (cp)! How should I find that???
and may I have your weblog address pls??

[CFDtoy]

Create surface (blade surface) and extract pressure coefficient? FLUENT lets you do it pretty straightforward. You will then have distribution of Cp over the surface and you can even create co-ordinates over the surface to check the Cp distribution.

CFDtoy

Visit http://cfdtoy.blogspot.com

Originally Posted by sabaeieng

Thank you very much CFDtoy, I gave the answer of my questions from your post but still I have some doubts about calculation of (cp)! How should I find that???
and may I have your weblog address pls??

[sabaeieng]

Dear CFDtoy
I think my answer made you mistake!
Cp in wind turbines is completely different from Pressure coefficient, it's POWER coefficient, so if I can find power of turbine or even torque of turbine I can find that. Would you please tell me how to find these two parameters.
Thanks for your help very much.

[dhanish]

i am running a 3d simulation of vertical axis turbine.Te torque and the cp is not coming down and increasing over the tip speed ratios.Can some help me with this?

[venkateshaero]

Torque will oscillate in periodic form, check the BC , Domain size , interface etc.....

[dhanish]

Thankyou for the reply,But
my torque values are as follows
tipspeed ratio torque
1 4
2 6
3 8
4 13
5 17

[venkateshaero]

Take average for last 50 cycles.