How to Properly Change Different Wind Directions

[axxyyyyyyyy378]

Hi everyone,

Recently I wanted to test the turbine's response to different wind directions. In the "5MW_OC4Semi_WSt_WavesWN" case, the default wind propagation direction is 0° (aligned with the positive X-axis, PropagationDir = 0°), and the turbine rotor and nacelle are directly facing the incoming wind (NacYaw = 0°, aligned with the negative X-axis).

I generated a turbulent wind field using TurbSim and changed the wind propagation direction in InflowWind to 90° (PropagationDir = 90°). Then I encountered some issues: Do I need to adjust other parameters? Should I set NacYaw to 90° in ElastoDyn to ensure the turbine faces the wind directly?
I tried this approach, but the program failed to run due to aerodynamic errors (see the first figure below). However, if I keep NacYaw = 0°, the program runs but still shows some warnings (see the second figure below). What adjustments should I make?

Thanks in advance.

[jjonkman]

Dear @axxyyyyyyyy378,

To minimize yaw error/misalignment, you should change the yaw angle when you change the wind direction.

However, PropagationDir in InflowWind uses meteorological convention (positive PropagationDir is clockwise when viewed from above) whereas the yaw angle in OpenFAST uses right-hand rule convention (positive NacYaw is counterclockwise when viewed from above). Thus, to minimize yaw error/misalignment, you should set NacYaw = -PropagationDir.

Note that if you change NacYaw and the nacelle-yaw degree of freedom of ElastoDyn is enabled (YawDOF = TRUE), you should also set YawNeut in the ServoDyn module equal to NacYaw or the nacelle will quickly snap from NacYaw back to YawNeut due to the nacelle-yaw spring in ServoDyn.

Best regards,

[axxyyyyyyyy378]

Dear @jjonkman,

Thank you for your professional response. My issue has been resolved.

Best regards,