Generating Turbsim wind file from 0m upwards

Hello,

I am trying to run a turbulent downwind simulation with the tower shadow effect turned on but I am getting the error “FF wind array boundaries violated”.

I followed the comments in [url]http://forums.nrel.gov/t/aerodyn-v15-convergence-issues/1305/13] which says[i] “Looking at the AWT27/Test04_AD15.ipt file, I see that the downwind tower shadow model is enabled (TwrShadow = True), with tower analysis nodes starting at ground level (TwrElev = 0). To run this model, you must use wind with data starting at the ground level.”

[/i] However, I am unable to generate wind files from 0m upwards using Turbsim. When I try to do this with a hub height of 200m and grid height & width of 400m, I get an error stating “The lowest grid point (0 m) must be above the ground. Adjust the appropriate values in the input file.” If I use a hub height of 200m and grid height & width of 390m, it generates wind files of heights 5m to 395m.

How do you recommend I go about solving this issue?

Thanks,
Tinu

Hi Tinu,

You are correct that TurbSim will not allow the main rectangular domain to extend down to ground level. However, you can generate wind in TurbSim down to ground level if you output the tower points below the main grid (WrADTWR = True). Another solution is to shift the lowest tower aerodynamic node in AeroDyn upward slightly, so, it is not at ground level.

Best regards,