Gravitational acceleration component in local blade sectional accelerations - Feature request

[IAbda]

Is your feature request related to a problem? Please describe.
Gravitational acceleration component is not included in the local blade flapwise and edgewise accelerations (e.g. Spn9ALxb1 , Spn9ALyb1). The blade (structural) accelerations are computed relative to the inertial frame; they do not include the gravity effect. This true for both Elastodyn and BeamDyn.

When comparing measured accelerometer data from wind turbine blades to OpenFAST simulations, it would necessary to include the graviational acceleration component as they are physically present in the field measurements.

Describe the solution you'd like
As an option, output the accelerations including gravity.

Describe alternatives you've considered
Let the user define the frame of reference overwhich they desire to output the blades acceleration signals.

Additional context
N/A

[jjonkman]

Dear @IAbda,

Thanks for posting this feature request. I agree that this feature is needed. I'm envisioning a flag added to the input file of each structural module of OpenFAST indicating whether the gravitational acceleration should be added to the translational acceleration-related write outputs.

Best regards,

[IAbda]

Dear @jjonkman,

may I please come back to this issue. Do you know the timeline when this might be implemented?

thanks a lot and best regards,
Imad

[andrew-platt]

There is a pull request in the queue as of this morning to add these channels to ElastoDyn: #1760. I'm not sure at the moment which channels have been added as I have not had a chance to review it.

[andrew-platt]

This is addressed in the v4.0.0 release (#2586)

[jjonkman]

I'm reopening this issue. It looks like the acceleration outputs with gravity were added to ElastoDyn in OpenFAST v4, but not to BeamDyn or SubDyn yet.

[gatosardina]

sorry for the comment, i'm following the development of OF eagerly awaiting the 5.0 release, I reckon this issue should be re-tagged to milestone 4.0.1 or 5.0 as to not let it fall into oblivion