## Search found 37 matches

Fri Nov 13, 2020 7:14 am
Forum: General
Topic: Wind turbine initial conditions
Replies: 2
Views: 324

### Re: Wind turbine initial conditions

Dear Jason,

Once again thankful for your time and valuable insights.
Fri Nov 13, 2020 4:17 am
Forum: General
Topic: Wind turbine initial conditions
Replies: 2
Views: 324

### Wind turbine initial conditions

Dear Jason and all, Please correct me, if I'm wrong. According to my understanding, for every DLC the user assigns initial conditions (here mainly, Blade pitch and RPM ) to reduce the transient period of the simulations and to help the the controller find the stability earlier as possible. For the s...
Mon Sep 28, 2020 3:25 am
Forum: Computer-Aided Engineering Software Tools
Topic: Free decay analysis and natural frequency
Replies: 49
Views: 10612

### Re: Free decay analysis and natural frequency

Dear Akheel,

Addressing your first question: In the ElastoDyn input file you can find initial platform displacements (6DOF's). Give an offset value onetime for each DOF and then can verify how the system decays before it finds a new equilibrium position. Hope this helps

Kind regards
Thu Sep 24, 2020 12:17 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, Thanks for the detailed explanations. I verified the NREL_5MW example files with standalone beamdyn driver and the solution converges for 0.25s (smallest). As explained in the previous post, my model with very less DOFs converges at 0.04s. I am assuming it is the result of high frequenci...
Wed Sep 23, 2020 6:52 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, Maybe I wasn't explaining my self very well. Standalone beamdyn + order_elem 4 = 0.04s time step (the smallest verified) Standalone beamdyn + order_elem 33 = 0.002s time step Coupled to OpenFAST + order_elem 4 = 0.0001s time step My aim is to reduce the time step so that the total simula...
Wed Sep 23, 2020 2:24 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, Once again thanks for the informative insights. I am able to compile the standalone BeamDyn driver. The balde structure with lesser order_elem say 4, the solution converges even for a time step of 0.01s. As you explained, with the increase in mesh elements (through iterations I verified ...
Tue Sep 22, 2020 7:29 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, Thanks for the info. I have shared the issue on github. I will recompile the driver myself. As you mentioned old NWTC library is really old (last updated 4 years ago) When recompiling can I use BeamDyn source file and directories from OpenFAST library, instead of old NWTC ones? What I me...
Tue Sep 22, 2020 7:10 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason,

Outside the old NWTC library, is there any repository for BeamDyn standalone direct binaries or source code for recompilation? Myself, I wasn't able to find any other sources.

Thanks and kind regards
Tue Sep 22, 2020 2:52 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason and Bonnie, The following question is off-topic from this thread. But I haven't found any relevant threads for standalone BeamDyn driver. From the github repository (https://github.com/old-NWTC/BeamDyn) downloaded the data. It doesn't contain any BeamDyn driver binaries directly to use. I...
Mon Sep 21, 2020 8:14 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, Thanks for the informative insights. I kept total number of members to 1 with 34 key points. (Hoping that the number of key points doesn't effect the simulation time-step. I made sure that the curve is smoother) Order_elem as 4 initially. In the OpenFAST guide section 4.5.3.4, there is c...
Mon Sep 21, 2020 12:05 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, As you mentioned, I used member_total 4 in the previous simulations with 34 key points (kp_total). After your comment, I tired with member_total 1, and the simulation runs with 0.0003s (previously it was 0.0001). What could be the possible reason for such very high frequencies? Blade str...
Thu Sep 17, 2020 2:36 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, The attached natural frequencies are in Hz. With your suggestion, using the runCampbell script I did linearization for 4 operating points. (LinearizationPoints_Servo file considered from example directory) The Campbell plot script is running but not producing any results. Here in the fol...
Wed Sep 16, 2020 3:48 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, With the insights from previous threads on Natural frequencies, using MBC3 script I have calculated the natural frequencies. Parked DLC with exclusion of Aero and Inflow(Only Elasto, Beam and Servo activated), and the linearization performed for debug (all inputs, outputs & inclusion...
Tue Sep 15, 2020 3:44 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, I am facing exactly the same issue of convergence for some simulations, with OpenFASTv2.3.0 and a time step of 0.0001s ''FAST_Solution:FAST_AdvanceStates:B1:BD_GA2:BD_DynamicSolutionGA2:Solution does not converge after the maximum number of iterations FAST encountered an error at simulat...
Mon Sep 14, 2020 12:11 am
Forum: Computer-Aided Engineering Software Tools
Topic: The prebent blade and aerodyn15
Replies: 33
Views: 4679

### Re: The prebent blade and aerodyn15

Dear Jason, Thanks for the insights. I will use caution while working with BeamDyn. Could you please explain or guide me to a thread where I can learn more about this bug that you mentioned. My present aim is to work with a prebent blade. The Stiffness matrix of the blade sections are well defined a...