Search found 23 matches

by Florian.Stache
Tue Jul 11, 2017 1:23 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Generator Short-circuit simulation: FAST
Replies: 5
Views: 1256

Re: Generator Short-circuit simulation: FAST

Hi,

we implement short circuit events into our BLADED-Style DLL using matlab/simulink.

Regards,
Florian
by Florian.Stache
Tue May 09, 2017 1:57 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Subdyn with Full FE option
Replies: 3
Views: 666

Re: Subdyn with Full FE option

Dear Jason, thank you for the response. I tried also with smaller NDiv. I wanted to run only one short time serie with FE and this particular offshore structure as it is not fully symmetric I wanted to see if there is some difference to the CB reduced model. Particularly the effect of oblique bendin...
by Florian.Stache
Tue May 09, 2017 1:26 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Compiling FAST using GNU gfortran compiler for fast execution
Replies: 1
Views: 870

Re: Compiling FAST using GNU gfortran compiler for fast execution

Hi,
we have made the same experience. Gfortran results in slower executable compared to intel fortran compiler. We tried many settings but could not really improve the poor performance.

Regards,
Florian Stache

morewind engineering solutions
by Florian.Stache
Tue May 09, 2017 1:22 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Subdyn with Full FE option
Replies: 3
Views: 666

Subdyn with Full FE option

Hello, does anybody have experience with full FE calculation using subdyn. We have a model of a tripod/tripile structure which runs stable and with plausible reuslts using the modal reduction (CM) but crashes if we switch it to full FE. The whole setup including aerodynamics, bladed DLL ... runs as ...
by Florian.Stache
Tue May 09, 2017 1:15 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Questions about Parallel Computing
Replies: 2
Views: 553

Re: Questions about Parallel Computing

Hello, we are doing parallel computing by distributing thousands of single load cases (single FAST instances) into our network with several workstations using HTCondor. Condor is open source and manages the jobs within your cluster. Each load case does not run so long. The problem is indeed more the...
by Florian.Stache
Thu Apr 06, 2017 3:55 am
Forum: Computer-Aided Engineering Software Tools
Topic: Stand-Alone AeroDyn
Replies: 5
Views: 1075

Re: Stand-Alone AeroDyn

Dear FAST community, we are looking for a setup using Aerodyn and inflowwind as stand alone and where we would ideally input at each time step only the rotor speed/position and pitch angle (blades and tower are stiff). Ideally it should run with turbulent wind fields. Does anyone has some hints on h...
by Florian.Stache
Wed Nov 23, 2016 6:08 am
Forum: Computer-Aided Engineering Software Tools
Topic: numerical spikes in pitch moment
Replies: 3
Views: 607

Re: numerical spikes in pitch moment

Dear Jason, Thank you for your prompt reply. I tested the same load case with Beddoes switched to steady in aerodyn and indeed it removes the spikes, see fig (blue with beddoes / red without beddoes). spikes2.PNG Anyhow it changes also the behavior of the turbine in the normal operation part of the ...
by Florian.Stache
Mon Nov 21, 2016 6:43 am
Forum: Computer-Aided Engineering Software Tools
Topic: numerical spikes in pitch moment
Replies: 3
Views: 607

numerical spikes in pitch moment

Hello, does anyone observes some numerical spikes in the pitching moments as shown in the plot? Pitch_spikes.PNG It appears always when the turbine has already stopped. This is a simulation for a small wind turbine. accordingly we have already a relatively small step size. Here the general solver se...
by Florian.Stache
Wed Sep 07, 2016 6:18 am
Forum: Rotor Aerodynamics
Topic: Dynamic Stall models
Replies: 8
Views: 9668

Re: Dynamic Stall models

Here we see the dynamic stall effects during a DLC 1p4 at a inner profile. The blue line is the static lift curve from the airfoil file. The dots are aerodyn outputs: DynStall.JPG We see huge lift happening. I think this is not really realistic anymore and that is why in Bladed you disable the Dyn S...
by Florian.Stache
Wed Sep 07, 2016 5:46 am
Forum: Rotor Aerodynamics
Topic: Dynamic Stall models
Replies: 8
Views: 9668

Re: Dynamic Stall models

I just realised that the stall angle parameter in airfoils is no longer used since FAST8. 1 Number of airfoil tables in this file 0.00 Table ID parameter 12.50 Stall angle (deg) 0.00 No longer used, enter zero 0.00 No longer used, enter zero 0.00 No longer used, enter zero -5.31 Zero lift angle of a...
by Florian.Stache
Wed Sep 07, 2016 3:29 am
Forum: Rotor Aerodynamics
Topic: Dynamic Stall models
Replies: 8
Views: 9668

Re: Dynamic Stall models

Hello, We have been doing some comparisons BLADED vs FAST and other tools. I think one source for discrepency is the parametrisation of the stall modell. In FAST you can manipulate a lot the effect by setting the stall-angle in the airfoil file. Normally you estimate the value using the airfoilprep ...
by Florian.Stache
Tue Sep 06, 2016 7:55 am
Forum: Computer-Aided Engineering Software Tools
Topic: instability in tower at high wind idling with yaw error
Replies: 13
Views: 2363

Re: instability in tower at high wind idling with yaw error

Dear Jason, thank you for you reply. You wrote in the earlier post: Yes, I'm familiar with the problem, as explained in the report you mentioned. I have talked to other modelers in Europe and heard that this problem has been seen in many different turbines and with different aero-elastic software. I...
by Florian.Stache
Tue Sep 06, 2016 2:37 am
Forum: Computer-Aided Engineering Software Tools
Topic: instability in tower at high wind idling with yaw error
Replies: 13
Views: 2363

instability in tower at high wind idling with yaw error

Hi All, I observe some increasing tower side-side vibrations at higher wind speeds and yaw error (DLC 6p2), see plot. Tower_oscillations.JPG I m wondering if it is real or related to some numerical instability. What is your opinion on that? Did anyone experienced a similar case? Best Regards, Floria...
by Florian.Stache
Thu Jun 16, 2016 12:44 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Time serie Viewer for FAST outb
Replies: 0
Views: 4039

Time serie Viewer for FAST outb

Hello FAST users, we have uploaded the matlab files and GUI for a nice outb-File viewer on matlab central. http://de.mathworks.com/matlabcentral/fileexchange/57703-mwtsviewer It makes life easier when analysing large amounts of load cases and sensors. You can also plot sensors against each other ins...
by Florian.Stache
Fri Nov 27, 2015 2:04 pm
Forum: Computer-Aided Engineering Software Tools
Topic: FAST Computation Time and Improvement
Replies: 9
Views: 5130

Re: FAST Computation Time and Improvement

Hi, It appears that the computing time is very much depending on the compiler used. Our experience shows differences betwenn Linux Gfortran and intel fortran but also different versions of intel fortran have different speed. It is worth trying. Try increasing the time step of the solver if possible....

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