Search found 4103 matches

by Jason.Jonkman
Tue Jun 18, 2019 12:36 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Problem with Crunch - column reference
Replies: 2
Views: 31

Re: Problem with Crunch - column reference

Dear Carol, Regarding the "invalid data column reference" error, a similar question has been asked and answered in the following forum topic: https://wind.nrel.gov/forum/wind/viewtopic.php?f=4&t=2271&p=12859. Yes, time is the first column and Wind1VelX is the second column in your ...
by Jason.Jonkman
Tue Jun 18, 2019 12:28 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Surface visualization of DTU-10 MW
Replies: 2
Views: 41

Re: Surface visualization of DTU-10 MW

Dear Ghaith,

This issue was fixed in December, 2018 with the following pull request into OpenFAST dev: https://github.com/OpenFAST/openfast/pull/212, which has now been released in OpenFAST v2.1.

Best regards,
by Jason.Jonkman
Tue Jun 18, 2019 12:23 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Parameter access in user subroutines
Replies: 7
Views: 157

Re: Parameter access in user subroutines

Dear Matthias,

It was possible in FAST v7 to directly control the yaw angle without enabling the YawDOF. However, this capability was removed from FAST v8 and OpenFAST. Yaw control is only possible in FAST v8 and OpenFAST when YawDOF is enabled.

Best regards,
by Jason.Jonkman
Tue Jun 18, 2019 6:30 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 210
Views: 23717

Re: FAST theory manual

Sent.
by Jason.Jonkman
Mon Jun 17, 2019 5:21 pm
Forum: Computer-Aided Engineering Software Tools
Topic: AeroDyn v 13 ERROR in time integration
Replies: 1
Views: 105

Re: AeroDyn v 13 ERROR in time integration

Dear Daniel,

I'm not familiar with this error message, so, I assume it is generated by SIMPACK rather than by AeroDyn. I would reach out to SIMIPACK technical support for help.

Best regards,
by Jason.Jonkman
Mon Jun 17, 2019 5:19 pm
Forum: Structural Analysis
Topic: Definition of parameters
Replies: 15
Views: 5589

Re: Definition of parameters

Hi Rocío, What I said is that ElastoDyn assumes the neutral axis and pitch axis are coincident. ElastoDyn also assumes the center of gravity of each cross section is coincident with the pitch axis. Obviously, the blade structural model of ElastoDyn is quite limited (bending only, no offsets of the m...
by Jason.Jonkman
Mon Jun 17, 2019 5:13 pm
Forum: General
Topic: Current modeling in Hydrodyn
Replies: 5
Views: 236

Re: Current modeling in Hydrodyn

Dear Tomas, If you only want to eliminate viscous effects, you should set all viscous drag coefficients (Cd) to zero in your HydroDyn input file. If you want to eliminate the strip-theory solution altogether (resulting in potential-flow-only model), you should eliminate all joints and members from y...
by Jason.Jonkman
Thu Jun 13, 2019 2:09 pm
Forum: Structural Analysis
Topic: Definition of parameters
Replies: 15
Views: 5589

Re: Definition of parameters

Dear Rocío, BlCrvAC and BlSwpAC input parameters in AeroDyn define the aerodynamic center of each airfoil cross section with respect to the blade coordinate system, as distances from the pitch axis. The actual location of the leading edge is not defined or used by AeroDyn (but often the aerodynamic ...
by Jason.Jonkman
Thu Jun 13, 2019 2:04 pm
Forum: General
Topic: Current modeling in Hydrodyn
Replies: 5
Views: 236

Re: Current modeling in Hydrodyn

Dear Tomas,

The PropPot flag disables all terms in the strip theory formulation, except for viscous drag, which is not otherwise accounted for in the potential-flow solution. So, your model does have viscous drag, which is why it is effected by current.

Best regards,
by Jason.Jonkman
Thu Jun 13, 2019 1:27 pm
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 210
Views: 23717

Re: FAST theory manual

Sent.
by Jason.Jonkman
Thu Jun 13, 2019 3:01 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 210
Views: 23717

Re: FAST theory manual

Sent.
by Jason.Jonkman
Wed Jun 12, 2019 10:46 am
Forum: Computer-Aided Engineering Software Tools
Topic: Parameter access in user subroutines
Replies: 7
Views: 157

Re: Parameter access in user subroutines

Dear Matthias, I would simply add LSS_Spd as an input argument to routine UserYawCont(). Routine CalculateStandardYaw, which calls routine UserYawCont(), already has access to the current value of the LSS_Spd in the input data structure, so, all you need do is add u%LSS_Spd to the argument list of U...
by Jason.Jonkman
Wed Jun 12, 2019 12:52 am
Forum: Computer-Aided Engineering Software Tools
Topic: Parameter access in user subroutines
Replies: 7
Views: 157

Re: Parameter access in user subroutines

Dear Matthias, That comment was added for an older version of FAST, when all data was global and accessible from any routine. The FAST modularization framework used in FAST v8 and OpenFAST supports data encapsulation, so that specific data is not available to a given routine unless that data is made...
by Jason.Jonkman
Tue Jun 11, 2019 2:39 pm
Forum: Rotor Aerodynamics
Topic: AeroDyn V15 standalone forces compared to coupled Aerodyne Openfast forces ( RtAeroFxh RtAeroFyh RtAeroFzh)
Replies: 2
Views: 163

Re: AeroDyn V15 standalone forces compared to coupled Aerodyne Openfast forces ( RtAeroFxh RtAeroFyh RtAeroFzh)

Dear Benjamin, You haven't stated how your OpenFAST model is set up, but I would guess you have structural degrees of freedom enabled, whose oscillations are causing oscillations in the aerodynamic loads. I would suggest disabling all of the structural DOFs in the OpenFAST (in which case the OpenFAS...
by Jason.Jonkman
Tue Jun 11, 2019 2:28 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Parameter access in user subroutines
Replies: 7
Views: 157

Re: Parameter access in user subroutines

Dear Matthias,

Are you using FAST v7 or FAST v8 / OpenFAST? The source code implementation is quite different between these forms of FAST.

Best regards,

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