Tower shadow effect in FAST (1.5MW, test13)

Wind & Water Computer-Aided Engineering Software Tools
1

Hello everyone,

I have a problem about tower shadow in Aerodyn, could you help me?

In FAST, I use test13-1.5MW wind turbine, but in the FASTCertTestCases.xls, I find in the wind model, tower shadow has not been taken into account, shown below. (I think mainly because it’s upwind turbine).

Tower Shadow Yaw Error (deg) Shear Exponent Turbulence

  No                         0.0                    0.2                     Yes

I wanna take tower shadow into account, so I looked through the forum, and found Bonnie’s suggestion Tower shadow model in Aerodyn - #7 by Bonnie.Jonkman
so in the test13.ipt, I made the following change as the suggestion.
NEWTOWER TwrShad
True TwrPotent - Calculate tower potential flow (flag) INSTEAD OF 9999.9 ShadHWid - Tower-shadow half width (m)
True TwrShadow - Calculate tower shadow (flag) INSTEAD OF 9999.9 T_Shad_Refpt- Tower-shadow reference point (m)
“AeroDyn_Tower.dat” TwrFile - Tower drag file name (quoted string)

But I don’t know how to get the Aerodyn_Tower.dat, can I make the data (the TwrWid is taken from the sample of 5MW), shown as follows:

NREL 1.5 MW baseline aerodynamic tower CD input properties.
Used with AeroDyn 13.00.00 hidden tower influence feature.
10 NTwrHt - Number of tower input height stations listed (-)
1 NTwrRe - Number of tower Re values (-)
1 NTwrCD - Number of tower CD columns (-)
0.1 Tower_Wake_Constant - Tower wake constant (-) {0.0: full potential flow, 0.1: Bak model}
---------------------- DISTRIBUTED TOWER PROPERTIES ----------------------------
TwrHtFr TwrWid NTwrCDCol
0.1 5.574 1
0.2 5.361 1
0.3 5.148 1
0.4 4.935 1
0.5 4.722 1
0.6 4.509 1
0.7 4.296 1
0.8 4.083 1
0.9 3.870 1
1.0 3.870 1
---------------------- Re v CD PROPERTIES --------------------------------------
TwrRe TwrCD1 TwrCD2 TwrCD2 …
1.0 0.0

Question 1: Is there any problem doing so?
Question 2: If the Aerodyn_Tower.date is the correct, does it mean the Test13 in FAST can take tower shadow into account?
Hope you can give me some suggestions. Thanks a million!
Looking forward to your reply!

Best regards,
Yunqian Zhang

2

Dear Yunqian,

Yes, you can add the new upwind tower influence available in AeroDyn v13.00.00a-bjj to the 1.5-MW turbine simulated in FAST’s Test13 by enabling the appropriate settings in AeroDyn. There is a sample AeroDyn_Tower.dat file included in the “Samples” folder of the archive for AeroDyn v13.00.00a-bjj. This sample is for the NREL 5-MW baseline wind turbine. You will, of course, need to modify the inputs in this file (especially the tower width, TwrWid), so that they are appropriate for the 1.5-MW turbine.

I hope that helps.

Best regards,

3

Dear Jason,

Thank you for your help.

Best regards,
Yunqian Zhang