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### Re: Movable trailing edge flaps implementation

Posted: **Fri Sep 09, 2016 6:23 am**

by **Jason.Jonkman**

Dear Chaitanya,

I can't comment on the XFLR5 tool, but you should be aware that the airfoil polars for the blades of the NREL 5-MW turbine in the FAST archive include the influence of 3D corrections, including corrections for rotational augmentation (stall delay) and deep-stall drag (Viterna). Please see Section 3 of the NREL 5-MW specifications report for more information:

http://www.nrel.gov/docs/fy09osti/38060.pdf.

Best regards,

### Re: Movable trailing edge flaps implementation

Posted: **Fri Sep 09, 2016 8:41 am**

by **Xiao.Sun**

Dear Majjari,

The XFOIL is based on the planar flow theory if I remember correctly.

The accuracy is limited. For a more accurate estimation, I would use CFD.

It is also good to start with a clean airfoil to calibrate your flow simulation model.

For XFLR5, you can play with different Reynolds number, Mach number and Ncrit. Then adjust it with AirfoilPrep to account for 3D effects.

Finally compare with the provided reference data.

Thanks.

Xiao

### Re: Movable trailing edge flaps implementation

Posted: **Thu Sep 15, 2016 3:40 am**

by **Srinivasa.Sudharsan**

Hi xiao,

To generate airfoil data ,using Xflr5 i have designed a foil and flap angle as 1,2,3,4,5 degrees. Using the XY coordinates , i have substituted in airfoilprep.But there no much change in the output CL and CD values.please brief the steps to generate the airfoil data using these two softwares. For what the Xflr5 is used and for what the airfoilprep is used????? Kindly explain the steps!!

### Re: Movable trailing edge flaps implementation

Posted: **Thu Sep 15, 2016 8:27 am**

by **Xiao.Sun**

Hello Srinvasa,

For the XFLR5, you design the airfoil with flap by defining the profile coordinates. Then you perform a XFOIL direct analysis by changing the angle of attack, you will get a series of aerodynamic coefficients, which are purely 2D.

Here is an example for XFLR5 analysis:

https://www.youtube.com/watch?v=IFCL8IJlYnIFor airfoilprep, it is a correction for 3D effects. The initially aerodynamic coefficients should be obtained from XFLR5. After you get the coefficient, you paste them into airfoilprep, do the interpolate for the angle of attack, correction for the 3D effects, etc. The first README file explains the procedure.

### Re: Movable trailing edge flaps implementation

Posted: **Wed Sep 21, 2016 4:11 am**

by **Srinivasa.Sudharsan**

hi Xioa sir;

Everything is ok sir. But where to get the XY coordinates of the blades used in the NREL wind turbine and also how to check the flap action(ie) the airfoil switching in FAST-MATLAB interface. I have designed the airfoil for different flap angles -5 to 5 degrees,

### Re: Movable trailing edge flaps implementation

Posted: **Wed Sep 21, 2016 7:44 am**

by **Jason.Jonkman**

Dear Srinivasa,

Regarding the airfoil geometry of the NREL 5-MW baseline turbine, please see my post dated Jun 04, 2012 in the following forum topic:

viewtopic.php?f=2&t=440&p=1551.

Best regards,

### Re: Movable trailing edge flaps implementation

Posted: **Wed Sep 21, 2016 8:45 am**

by **Xiao.Sun**

Hello Srinvasa,

I suppose you are designing a feedback control scheme.

In order to check the flap angle, what I did is to add a scope module before I feed the flap angle signal back to the FAST module .

(To find it, you can search scope in Simulink library).

Best,

Xiao

### Re: Movable trailing edge flaps implementation

Posted: **Wed Sep 21, 2016 9:05 am**

by **Srinivasa.Sudharsan**

Hi xiao,

I am asking about the impact of the flap angle input in FAST outputs!!not while inputting the flap angle??? is there any way to display the switching of airfoil data based on the flap deflection outside ???

### Re: Movable trailing edge flaps implementation

Posted: **Wed Sep 21, 2016 9:18 am**

by **Xiao.Sun**

You can export the aerodyn data of the blade-flap section.

In aerodyn input file, switch NOPRINT to PRINT.

### Re: Movable trailing edge flaps implementation

Posted: **Wed Sep 21, 2016 10:02 am**

by **Srinivasa.Sudharsan**

thank you xiao;

sir i have another query that , i have chosen number of foil as 10 If i try to use flap at 70% of radius of the blade then is it enough to use the xfoil designed data for last 3 airfoil file ?? i have attached the aerodyn input file with the data you have sent with flap -5,0 and 5 degree. is my ideology is correct???

### Re: Movable trailing edge flaps implementation

Posted: **Tue Oct 16, 2018 7:49 am**

by **Majid.Ebr**

Hello everyone

I did the changes to source code and follow the instructions, Dr.Xiao Sun presented. but the flap angle input signal doesn't work apparently.

I doubt that doing the compiling instruction correctly, so I write the steps I did.

I used "open project" in "Intel parallel studio XE 2013 with vs2010" compiler and open "Simulink\VisualStudio, FAST_Library.vfproj" file. then I debugged that file without any errors and with 28 warnings.

after that I do the rest of instructions, such as altering "s_function parameters".

if I did not compile correctly, Let me know.

Thank you

### Re: Movable trailing edge flaps implementation

Posted: **Tue Aug 13, 2019 2:24 am**

by **Ning.Wang**

Srinivasa.Sudharsan wrote:hi Xiao.Sun;

i am trying the alter the source code as per your instructions. The doubt is in FAST_subs.f90 file in how many place should we insert the code:

" IF ( p_FAST%CompAero == Module_AD14 ) THEN

!Xiao Sun: add m_FAST

CALL AD14_InputSolve_NoIfW( p_FAST, m_FAST, AD14%Input(1), ED%Output(1), MeshMapData, ErrStat2, ErrMsg2 )

CALL SetErrStat( ErrStat2, ErrMsg2, ErrStat, ErrMsg, RoutineName ) ".

you have given the same code twice in the previous post, whether we have to edit the exiting code or insert below. And also what about AD14

, is it enough to mention as "AD" alone or is there any special reason behind mentioning it as "AD14". kindly reply thank you!!!

Dear Srinivasa.Sudharsan，

I want to ask you how to solve the problem mentioned above. I've met the same question,Could you help me,thanks!

### Re: Movable trailing edge flaps implementation

Posted: **Tue Aug 13, 2019 2:28 am**

by **Ning.Wang**

Majid.Ebr wrote:Hello everyone

I did the changes to source code and follow the instructions, Dr.Xiao Sun presented. but the flap angle input signal doesn't work apparently.

I doubt that doing the compiling instruction correctly, so I write the steps I did.

I used "open project" in "Intel parallel studio XE 2013 with vs2010" compiler and open "Simulink\VisualStudio, FAST_Library.vfproj" file. then I debugged that file wihout any errors and with 28 warnings.

after that I do the rest of instructions, such as altering "s_function parameters".

if I did not compile correctly, Let me know.

Thank you

Dear Majid.Ebr,

Could you help me how you solevd the problem later,thank you!