Hi,
I am modelling the IEA 22MW turbine with a fixed base and running a range of turbulent wind cases similar to Orcina’s setup in IEA 22 MW RWT validation study - Orcina for load case 3.5 (full-field, IEC 61400-1IB ETM). I’m running this setup for mean wind speeds from 3 - 25 m/s to get statistics, for OpenFAST I’ve had no issues apart from 11 m/s & 13 m/s are aborting due to this error message:
Figure 1: Error message from my initial 13 m/s run:
Figure 2: Results from the final 100s of the total 400s simulation, compared to OrcaFlex:
I tried 11 & 13 m/s for a second time in OpenFAST and got a similar result - both failing around 200s without any obvious reasons from looking at the results.
I know that these are the wind speeds near the maximum rotor thrust and flapwise deflections but I can’t quite understand why they are failing when 10,12,14 m/s etc run without any problems.
Figure 3: Full timehistory for 11 m/s:
Figure 4: Full timehistory for 12 m/s:
For other information: the same turbsim .bts files are used in both OpenFAST & OrcaFlex and the simulations are ran with an initial rotor speed of 3 rpm. And the only changes to the setup between speeds is the URef in the turbsim input file.
Can anyone here suggest anything that might be causing these failures?
Thanks,
Barry Britton
University of Galway, Ireland