Is positive Yaw error clockwise?

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Alec.Mackendrick
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Is positive Yaw error clockwise?

Postby Alec.Mackendrick » Mon Sep 10, 2012 2:11 am

Hi

It seems like the industrial standard approach to yaw misalignment is that if the wind is approaching your turbine from a slightly clockwise direction (when viewed from above) to where your turbine is facing then you have a positive yaw error. To correct the error, you would yaw clockwise, in a positive direction.

Sadly this doesn't tie up with maths, which likes anti clockwise to be positive. I guess following the industrial standard, positive yaw moments would cause negative movements. I've had a quick rummage through the FAST manual, and it doesn't explicitly say which approach is followed (maths vs industrial standard).

Please could you let me know which way is positive when yawing and would you consider adding a top down view of a turbine to the manual in the section where the coordinate systems are described?

Thanks

Alec
Alec MacKendrick
Senior Control Specialist, EMEA
Lloyd's Register Group Limited

Jason.Jonkman
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Re: Is positive Yaw error clockwise?

Postby Jason.Jonkman » Mon Sep 10, 2012 7:16 am

Dear Alec,

In FAST, the wind direction output (HorWndDir), nacelle yaw angle input/ouput (NacYaw) and nacelle yaw error output (NacYawErr) are all defined counter-clockwise when looking from above (this is a positive rotation about the z-axis, which points vertically upwards). In AeroDyn, the wind direction input (WindDir) is defined clockwise when looking from above (which is opposite to that of FAST). For example, in Test01 from the FAST CertTest, NacYaw = -15 degrees and WindDir = -HorWindDir = 30 degrees, which equals NacYawErr = -15 degrees.

I hope that helps.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Alec.Mackendrick
Posts: 40
Joined: Thu Jun 28, 2012 10:37 am
Organization: Lloyd's Register
Location: UK

Re: Is positive Yaw error clockwise?

Postby Alec.Mackendrick » Mon Sep 10, 2012 9:36 am

Thanks Jason, yes it does.
Alec
Alec MacKendrick
Senior Control Specialist, EMEA
Lloyd's Register Group Limited

Julia.Hahn
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Organization: EnBW Energie Baden-Württemberg AG
Location: Germany

Re: Is positive Yaw error clockwise?

Postby Julia.Hahn » Fri Jul 17, 2015 2:39 am

Hi everyone,

I just want to make sure that I understood the explanation concerning FAST’s yaw convention right.
Would you be so kind to confirm that the picture I created is correct?
It’s supposed to show the turbine viewed from above. The black arrows point out the rotation direction of the blades.

Thanks – and kind regards,
Julia
Attachments
Yaw Direction.jpg
Yaw Direction.jpg (61.03 KiB) Viewed 5877 times

Jason.Jonkman
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Re: Is positive Yaw error clockwise?

Postby Jason.Jonkman » Fri Jul 17, 2015 6:30 am

Dear Julia,

Yes, your image is correct.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Julia.Hahn
Posts: 6
Joined: Wed Jun 10, 2015 12:59 am
Organization: EnBW Energie Baden-Württemberg AG
Location: Germany

Re: Is positive Yaw error clockwise?

Postby Julia.Hahn » Mon Jul 20, 2015 3:58 am

Dear Jason,

thanks a lot for the quick response!

Best regards,
Julia

Mark.Capellaro
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Re: Is positive Yaw error clockwise?

Postby Mark.Capellaro » Mon Feb 20, 2017 5:30 am

RE: FASTV8.16
Are any of the yaw options possible with the newest versions of FAST?
Mark C

Jason.Jonkman
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Re: Is positive Yaw error clockwise?

Postby Jason.Jonkman » Mon Feb 20, 2017 6:32 am

Dear Mark,

What yaw options are you referring to?

Regardless, the yaw functionality is virtually unchanged between FAST v8.16 and earlier versions.

Best regards,
Jason Jonkman, Ph.D.
Senior Engineer | National Wind Technology Center (NWTC)

National Renewable Energy Laboratory (NREL)
15013 Denver West Parkway | Golden, CO 80401
+1 (303) 384 – 7026 | Fax: +1 (303) 384 – 6901
nwtc.nrel.gov

Mark.Capellaro
Posts: 12
Joined: Wed Aug 10, 2016 7:50 am
Organization: Disgruntled Goat GmbH
Location: Bavaria

Re: Is positive Yaw error clockwise?

Postby Mark.Capellaro » Mon Feb 20, 2017 6:51 am

forgot to look under elastodyn inputs. thanks. M


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