# Tower shadow effect in FAST (1.5MW, test13) **URL:** \ **Category:** Computer-Aided Engineering Software Tools\ **Created:** [May 20, 2011, 9:15pm UTC](https://forums.nlr.gov/t/tower-shadow-effect-in-fast-1-5mw-test13/364 "2011-05-20T21:15:51Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Yunqian.Zhang](https://avatars.discourse-cdn.com/v4/letter/y/58f4c7/32.png) [@Yunqian.Zhang](https://forums.nlr.gov/u/Yunqian.Zhang)\ **Post date:** [May 20, 2011, 9:15pm UTC](https://forums.nlr.gov/t/tower-shadow-effect-in-fast-1-5mw-test13/364/1 "2011-05-20T21:15:51Z")
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](http://forums.nlr.gov/t/tower-shadow-model-in-aerodyn/85/7) 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 ---
**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\ **Post date:** [May 20, 2011, 11:54pm UTC](https://forums.nlr.gov/t/tower-shadow-effect-in-fast-1-5mw-test13/364/2 "2011-05-20T23:54:40Z")
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, ---
**Author:** ![Yunqian.Zhang](https://avatars.discourse-cdn.com/v4/letter/y/58f4c7/32.png) [@Yunqian.Zhang](https://forums.nlr.gov/u/Yunqian.Zhang)\ **Post date:** [May 21, 2011, 11:44am UTC](https://forums.nlr.gov/t/tower-shadow-effect-in-fast-1-5mw-test13/364/3 "2011-05-21T11:44:19Z")
Dear Jason, Thank you for your help. Best regards, Yunqian Zhang