Blade for a 20 mw owt

Wind & Water Computer-Aided Engineering Software Tools
1

Hello,

May somebody tell me why i receive this error in the cmd when i run a simulation for a 20 MW WT?

image
image894×194 8.13 KB

Hereafter i show the image related to Elastodyn_blade. Probably the mistake comes from the values BldFlDmp1,BldFlDmp2 and BldEdDmp1? However, i have tried modifying these, but still i get Openfast aborted.

The values have been upscaled according to linear geometrical scaling, and as you can see this file has the same values (as the blade for the 15 MW WT), but with the blade distributed properties varying:

------- ELASTODYN V1.00.* INDIVIDUAL BLADE INPUT FILE --------------------------
20 MW WIND TURBINE
---------------------- BLADE PARAMETERS ----------------------------------------
50 NBlInpSt - Number of blade input stations (-)
0.48 BldFlDmp1 - Blade flap mode #1 structural damping in percent of critical (%)
0.48 BldFlDmp2 - Blade flap mode #2 structural damping in percent of critical (%)
0.48 BldEdDmp1 - Blade edge mode #1 structural damping in percent of critical (%)
---------------------- BLADE ADJUSTMENT FACTORS --------------------------------
1.0 FlStTunr1 - Blade flapwise modal stiffness tuner, 1st mode (-)
1.0 FlStTunr2 - Blade flapwise modal stiffness tuner, 2nd mode (-)
1.0 AdjBlMs - Factor to adjust blade mass density (-)
1.0 AdjFlSt - Factor to adjust blade flap stiffness (-)
1.0 AdjEdSt - Factor to adjust blade edge stiffness (-)
---------------------- DISTRIBUTED BLADE PROPERTIES ----------------------------
BlFract PitchAxis StrcTwst BMassDen FlpStff EdgStff
(-) (-) (deg) (kg/m) (Nm^2) (Nm^2)
0.000000E+00 5.045455E-01 1.559455E+01 4.252194E+03 2.711714E+11 2.710742E+11
2.040816E-02 4.900187E-01 1.558774E+01 3.797989E+03 2.467589E+11 2.446931E+11
4.081633E-02 4.727002E-01 1.541083E+01 3.341756E+03 2.173912E+11 2.188522E+11
6.122449E-02 4.540148E-01 1.494856E+01 2.835103E+03 1.728254E+11 1.831180E+11
8.163265E-02 4.346478E-01 1.425845E+01 2.365697E+03 1.328566E+11 1.496074E+11
1.020408E-01 4.156279E-01 1.339714E+01 2.233887E+03 1.008127E+11 1.333393E+11
1.224490E-01 3.979379E-01 1.242202E+01 1.833829E+03 7.703324E+10 1.135444E+11
1.428571E-01 3.812996E-01 1.139457E+01 1.502503E+03 6.201119E+10 9.933422E+10
1.632653E-01 3.654921E-01 1.037098E+01 1.222262E+03 5.465001E+10 8.623010E+10
1.836735E-01 3.516078E-01 9.404000E+00 1.010817E+03 4.923247E+10 7.518965E+10
2.040816E-01 3.400844E-01 8.551522E+00 8.664269E+02 4.376832E+10 6.718185E+10
2.244898E-01 3.310671E-01 7.833153E+00 7.755464E+02 3.802726E+10 6.152070E+10
2.448980E-01 3.241031E-01 7.191355E+00 7.184147E+02 3.323100E+10 5.729493E+10
2.653061E-01 3.188473E-01 6.551629E+00 6.791847E+02 2.900063E+10 5.390431E+10
2.857143E-01 3.146896E-01 5.933996E+00 6.570456E+02 2.629584E+10 5.096680E+10
3.061224E-01 3.114889E-01 5.346090E+00 6.490394E+02 2.503391E+10 4.834154E+10
3.265306E-01 3.088429E-01 4.796334E+00 6.429729E+02 2.383146E+10 4.555648E+10
3.469388E-01 3.066054E-01 4.296594E+00 6.349123E+02 2.156469E+10 4.278735E+10
3.673469E-01 3.043613E-01 3.846955E+00 6.237217E+02 1.880115E+10 4.023144E+10
3.877551E-01 3.018757E-01 3.445342E+00 6.121729E+02 1.676256E+10 3.805666E+10
4.081633E-01 2.992018E-01 3.076914E+00 6.011172E+02 1.543000E+10 3.609875E+10
4.285714E-01 2.964858E-01 2.733562E+00 5.895998E+02 1.438363E+10 3.423939E+10
4.489796E-01 2.939712E-01 2.412235E+00 5.768011E+02 1.321017E+10 3.236039E+10
4.693878E-01 2.918572E-01 2.111691E+00 5.626365E+02 1.161407E+10 3.051851E+10
4.897959E-01 2.901099E-01 1.828396E+00 5.483379E+02 1.001859E+10 2.874322E+10
5.102041E-01 2.888066E-01 1.558783E+00 5.349965E+02 8.755075E+09 2.706285E+10
5.306122E-01 2.880263E-01 1.302437E+00 5.227293E+02 7.825503E+09 2.548815E+10
5.510204E-01 2.878415E-01 1.064427E+00 5.102234E+02 7.006358E+09 2.390217E+10
5.714286E-01 2.879425E-01 8.434462E-01 4.816882E+02 6.091259E+09 2.023290E+10
5.918367E-01 2.885226E-01 6.365642E-01 4.531546E+02 5.274099E+09 1.683850E+10
6.122449E-01 2.895769E-01 4.370289E-01 4.230997E+02 4.620396E+09 1.350768E+10
6.326531E-01 2.911108E-01 2.396568E-01 3.921532E+02 4.088185E+09 1.032116E+10
6.530612E-01 2.930139E-01 3.967769E-02 3.625762E+02 3.602590E+09 7.619052E+09
6.734694E-01 2.952412E-01 -1.728281E-01 3.417526E+02 3.111990E+09 6.292691E+09
6.938776E-01 2.977841E-01 -4.070838E-01 3.191689E+02 2.632239E+09 5.081496E+09
7.142857E-01 3.005653E-01 -6.803776E-01 2.962087E+02 2.179121E+09 4.287019E+09
7.346939E-01 3.035754E-01 -9.992936E-01 2.695170E+02 1.762776E+09 3.660930E+09
7.551020E-01 3.067045E-01 -1.320525E+00 2.407392E+02 1.416021E+09 3.042763E+09
7.755102E-01 3.098825E-01 -1.623299E+00 2.102142E+02 1.134125E+09 2.389471E+09
7.959184E-01 3.130107E-01 -1.884368E+00 1.806453E+02 8.917388E+08 1.802308E+09
8.163265E-01 3.163904E-01 -2.086230E+00 1.494422E+02 6.822885E+08 1.389915E+09
8.367347E-01 3.202111E-01 -2.163998E+00 1.257162E+02 5.194938E+08 1.112419E+09
8.571429E-01 3.246231E-01 -2.175841E+00 1.040127E+02 3.972301E+08 8.627715E+08
8.775510E-01 3.294542E-01 -2.155304E+00 8.577216E+01 2.943008E+08 6.671407E+08
8.979592E-01 3.346331E-01 -2.102910E+00 7.125587E+01 2.095118E+08 5.189273E+08
9.183673E-01 3.401190E-01 -2.018403E+00 5.933780E+01 1.407404E+08 3.982165E+08
9.387755E-01 3.460556E-01 -1.896743E+00 4.892906E+01 8.750209E+07 2.900786E+08
9.591837E-01 3.527212E-01 -1.724326E+00 3.583154E+01 4.876947E+07 1.892122E+08
9.795918E-01 3.600890E-01 -1.508125E+00 2.876268E+01 2.305204E+07 1.193844E+08
1.000000E+00 3.681818E-01 -1.242388E+00 7.689843E+00 3.310242E+05 2.957002E+06

---------------------- BLADE MODE SHAPES ---------------------------------------
-0.0752915102669993 BldFl1Sh(2) - Flap mode 1, coeff of x^2
2.826459690437861 BldFl1Sh(3) - , coeff of x^3
-3.2702836497367604 BldFl1Sh(4) - , coeff of x^4
2.252110669909933 BldFl1Sh(5) - , coeff of x^5
-0.7329952003440339 BldFl1Sh(6) - , coeff of x^6
-0.5285519130664843 BldFl2Sh(2) - Flap mode 2, coeff of x^2
0.7090455925619575 BldFl2Sh(3) - , coeff of x^3
-7.795036256009813 BldFl2Sh(4) - , coeff of x^4
15.797380956455061 BldFl2Sh(5) - , coeff of x^5
-7.182838379940722 BldFl2Sh(6) - , coeff of x^6
-0.02913195484596477 BldEdgSh(2) - Edge mode 1, coeff of x^2
5.270503361982258 BldEdgSh(3) - , coeff of x^3
-11.024746168421133 BldEdgSh(4) - , coeff of x^4
10.34151438983642 BldEdgSh(5) - , coeff of x^5
-3.5581396285515794 BldEdgSh(6) - , coeff of x^6

Apart from this, i would like to know one potential question. I have the DISCON file for a wind turbine (supported in a monopile) in order to give 20 MW under certain wind speeds . I wanted to ask if it is possible to have the DISCON file modified for a wind turbine (BUT supported in a semi-submersible) in order to give 20 MW. If so, how? Because there are a lot of of parameters in the DISCON file and i Dont know which ones i shall modify in order to get the 20 MW of power for the semissub UMAINE.

Thanks

2

Dear @Alberto.Utrera,

As with any input-file processing error, I would enable the Echo option to debug issues assaciated with input file formatting. I’m not sure if this is a result of how you pasted in the data into this forum post, but I do see an extra line after the table of distributed blade properties that could be the problem.

Regarding the DISCON controller, if you are using ROSCO, you can use the ROSCO Toolbox to set many of the controller parameters for different wind turbines and support structures.

Best regards,

3

Hello @Jason.Jonkman , i am taking care of the ROSCO dilemma with the contributors, so thank you for referring me to them. I would like to ask you why this mistake comes up:

image
image1703×630 201 KB

If you need that i share any file with you , let me know

4

Dear @Alberto.Utrera,

The warning about high angle of attack is not necessarily a concern if it only happens inboard, where the rotation-induced translational velocity is small. But I would ensure that you are using proper initial conditions of rotor speed and blade-pitch for each mean wind speed based on their expected (mean) values conditioned on the mean hub-height wind speed.

The warning about high skew is problematic if you are not expecting large skew for this case, i.e., if you were expecting that the rotor is more or less aligned with the wind.

The last error about wind array boundaries violated in the Z direction is typically triggered by not extending the TurbSim wind domain low enough to cover the tower aerodynamic analysis nodes, when enabled.

Best regards,

5

Hello, @Jason.Jonkman , I am using the following initial conditions for a 20 MW wind turbine supported on a semisubmersible. This is a simulation for 11 m/s. The values for the blade pitch are 1.1759 because it is an interpolation made from 10.86 m/s and 11.17 m/s (from the “Rotor performance” page from the IEA tabular excel file). I have been slightly modifying the values for the initial blade pitch, and it does not seem to be the problem. Regarding the rotor speed, i have noted 6.5 rpm (the IEA tabular excel sheet has 7,5 rpm for a wind speed 11 m/s) because of an inverse scaling on rotor speed and rotor diameter (6.5=7.5*242/279). This does not seem to be the problem neither.

image
image1118×392 189 KB

About the problem with TurbSim i have an idea how to fix it, but how would you recommend to fix the problem with the warning about high skew?

Thanks. BR

6

Dear @Alberto.Utrera,

If I understand correctly, you upscaled the properties of the IEA Wind 15-MW RWT and made an OpenFAST model based on these upscaled properties. Did you upscale all properties (geometry, mass, stiffness) consistently and update the controller?

Regarding high skew, if you are not expecting it because you don’t believe there should be a large yaw misalignment, I would first figure if there are numerical issues with the solution (numerically instability induced large motion can trigger this warning).

Best regards,