Yawed inflow
1 Test description
In this test, the aerodynamic thrust on the NREL 5-MW reference wind turbine is measured for different wind speed and different inflow angles. The results from Ashes are compared to data produced by OpenFAST v4.0.2
2 Model
This test uses the Onshore template.
The simulation is run in Loads only and tower shadow is deactivated. The initial conditions (blade pitch and RPM) correspond to the steady-state values for the considered wind speed (at 0 degrees inflow) found in Jonkman et al. (2009o).
The wind speed is uniform.
3 Benchmarked solution
The thrust time series obtained from Ashes are compared to data produced by OpenFAST v4.0.2. In OpenFAST, 60-second long simulations were run with all degrees of freedom disabled and the skew momentum correction (SkewMomCorr = True in the AeroDyn input file). This allows OpenFAST to use the correction for skewed inflow developed by Branlard et al. (2024). The last 10 seconds of each simulations were averaged and used for comparison.
Simulations are run for wind speeds ranging from 3 to 17 m/s and inflow angles from 0 to 50 degrees, in steps of 10.
4 Results
A simulation of 20 seconds is run for each load case and the average . The test is considered passed if the results from Ashes are within 10% of those from OpenFAST, with the exception of the four load cases defined as {wind speed, angle} = {17,40}, {15,50}, {16,50}, {17,50}. This is likely to be a difference in the dynamic stall model. This will be analised in future tests.
The figure below presents the results from Ashes and from OpenFAST. This figure was produced on an instance where the test is passing. The tests are run every night, so the figure is valid (within the 10% error) if the test has passed.
The report for this test can be found on the following link: