Search found 4110 matches

by Jason.Jonkman
Mon Jun 24, 2019 9:46 am
Forum: Computer-Aided Engineering Software Tools
Topic: NREL 5MW Baseline Offshore Monopile Simulation
Replies: 3
Views: 176

Re: NREL 5MW Baseline Offshore Monopile Simulation

Dear Eduardo,

I can't speak to other output-related errors, but in your example from AeroDyn, I could foresee that you would get an invalid error for output TwN1VUndx if NTwOuts is not set to 1 or greater. What do you have NTwOuts set to in the primary AeroDyn input file?

Best regards,
by Jason.Jonkman
Mon Jun 24, 2019 9:06 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 214
Views: 24200

Re: FAST theory manual

Sent.
by Jason.Jonkman
Fri Jun 21, 2019 9:58 am
Forum: Controls
Topic: Super Controller for Farm Power Curtailment in Region 2
Replies: 1
Views: 49

Re: Super Controller for Farm Power Curtailment in Region 2

Dear Jordan, While the wind-farm super-controller implementation in FAST.FAST is nearly complete, it is still not yet functional in the current version. We intend to publicly release FAST.Farm after (1) the super controller has been fully implemented; (2) the user documentation has been finalized; a...
by Jason.Jonkman
Thu Jun 20, 2019 3:57 pm
Forum: Computer-Aided Engineering Software Tools
Topic: On generator power drop and pitch controller
Replies: 2
Views: 58

Re: On generator power drop and pitch controller

Dear Aditya, Yes, these dips in torque and power are associated with dips in the wind speed and result from the Region 3 to Region 2 transition of the controller. Presumably you are modeling the NREL 5-MW turbine. The baseline controller of this turbine is described in the NREL 5-MW specifications r...
by Jason.Jonkman
Wed Jun 19, 2019 9:28 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 214
Views: 24200

Re: FAST theory manual

Sent.
by Jason.Jonkman
Wed Jun 19, 2019 9:17 am
Forum: Controls
Topic: questions about reference control input
Replies: 52
Views: 10794

Re: questions about reference control input

Dear Behnam, In general, I would expect the linear and nonlinear system should have similar behavior for small perturbations about the operating point for models that are set up the same. I don't see any problem with the approach from your overview, but the devil is in the details. I would recommend...
by Jason.Jonkman
Wed Jun 19, 2019 6:50 am
Forum: Controls
Topic: questions about reference control input
Replies: 52
Views: 10794

Re: questions about reference control input

Dear Behnam, Yes, I can't comment on your specific results, but I would expect some small differences in the steady-state pitch angle associated with a given mean wind speed and rotor speed between FAST v8 and FAST v7 due to differences in the BEM solution between AeroDyn v15 in FAST v8 and AeroDyn ...
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: 76

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: 90

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: 210

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: 214
Views: 24200

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: 150

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: 5705

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: 323

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: 5705

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 ...

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