# Changing TMax to 600s simulation time

**URL:** <https://forums.nlr.gov/t/changing-tmax-to-600s-simulation-time/2285>\
**Category:** Computer-Aided Engineering Software Tools\
**Created:** [July 7, 2020, 9:40pm UTC](https://forums.nlr.gov/t/changing-tmax-to-600s-simulation-time/2285 "2020-07-07T21:40:41Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Julius.Scherf](https://avatars.discourse-cdn.com/v4/letter/j/ecc23a/32.png) [@Julius.Scherf](https://forums.nlr.gov/u/Julius.Scherf)\
**Post date:** [July 7, 2020, 9:40pm UTC](https://forums.nlr.gov/t/changing-tmax-to-600s-simulation-time/2285/1 "2020-07-07T21:40:41Z")

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Dear all,

Im trying to do a 600s simulation on the 5MW NREL onshore turbine, as needed for the IEC-61400 standard.  
I’m currently running test 18 with TMAX=60s. If I changed it to 600s the following error occurs(see attachments).  
Do I have to change some other mode or parameters to perform a 600s simulation?

Best wishes,  
Julius

 ![Screen Shot 2020-07-07 at 11.37.05 PM.png](https://europe1.discourse-cdn.com/nrel/original/2X/c/ca620d708f1a875b754883ea371231ce100235d9.png)

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**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:** [July 7, 2020, 11:11pm UTC](https://forums.nlr.gov/t/changing-tmax-to-600s-simulation-time/2285/2 "2020-07-07T23:11:38Z")

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Dear Julius,

The wind field generated by TurbSim must encompass the entire rotor for the entire simulation, including any structural displacement that might occur, or else you will get such errors. For a land-based wind turbine, I would typically set the grid size to be about 10% more than the rotor diameter in the horizontal and vertical directions. For a floating offshore wind turbine, I would set the grid size much larger. Please see the the forum topic linked here for an example TurbSim input file we’ve used for the NREL 5-MW baseline turbine: [Updated NWTC Design Codes Available on Our Web Site - #8 by Jason.Jonkman](http://forums.nlr.gov/t/updated-nwtc-design-codes-available-on-our-web-site/237/8).

Best regards,

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**Author:** ![Bonnie.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/bonnie.jonkman/32/3230_2.png) [@Bonnie.Jonkman](https://forums.nlr.gov/u/Bonnie.Jonkman)\
**Post date:** [July 8, 2020, 11:37pm UTC](https://forums.nlr.gov/t/changing-tmax-to-600s-simulation-time/2285/3 "2020-07-08T23:37:59Z")

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One other comment: The wind file distributed with the sample test cases contains is only about 60 seconds long. We did this to keep the size of the archives a reasonable size. If you want to run a longer simulation, you’ll have to use a different wind file.

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**Author:** ![Julius.Scherf](https://avatars.discourse-cdn.com/v4/letter/j/ecc23a/32.png) [@Julius.Scherf](https://forums.nlr.gov/u/Julius.Scherf)\
**Post date:** [July 10, 2020, 10:15am UTC](https://forums.nlr.gov/t/changing-tmax-to-600s-simulation-time/2285/4 "2020-07-10T10:15:53Z")

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Dear Jason,

thank you a lot. I changed the wind file and I could run the simulation for 600s. 🙂

Best wishes,  
Julius