Search found 40 matches

by Danny.Sale
Tue Jul 24, 2018 6:27 pm
Forum: Computer-Aided Engineering Software Tools
Topic: SOWFA Tutorial
Replies: 4
Views: 1463

Re: SOWFA Tutorial

hi Guillaume, can you post your solution? I am sure it will be helpful for other people who encounter similar problems, thanks!
by Danny.Sale
Tue Jul 24, 2018 6:07 pm
Forum: Airfoils
Topic: help needed in airfoil prep
Replies: 7
Views: 4711

Re: help needed in airfoil prep

To address the question: how to find the local chord? ... it is up to interpretation but when using HARP_Opt the chord is considered an unknown variable; however, you should be able to estimate the approximate chord length based on your upper/lower bounds ... or run HARP_Opt to completion once and u...
by Danny.Sale
Tue Jul 24, 2018 5:55 pm
Forum: Airfoils
Topic: help needed in airfoil prep
Replies: 7
Views: 4711

Re: help needed in airfoil prep

I think an ideal solution would be to modify the NWTC Library (or inside the WT_Perf code) to calculate the 3D correction, and then re-compile WT_Perf so that 3D corrections are calculated completely within the "blade element momentum" part of code. This would eliminate the burden of creat...
by Danny.Sale
Tue Jul 24, 2018 5:36 pm
Forum: Airfoils
Topic: The airfoil of AWT-27
Replies: 3
Views: 4356

Re: The airfoil of AWT-27

agree with Jason and Hermann, the airfoil polar "AWT-27" is probably an interpolation of the polars (by Relative Thickness % between the master polars of SERI airfoils), and then it could possibly have rotational or stall-delay corrections applied (anything from the AirfoilPrep worksheet).
by Danny.Sale
Tue Jul 24, 2018 5:23 pm
Forum: Tidal Current
Topic: Help needed regarding Harp_opt
Replies: 2
Views: 5589

Re: Help needed regarding Harp_opt

The airfoil files should be in the same format as WT_Perf and FAST (NWTC Library format). Modify the airfoil text files to match similar to all other NREL codes. Or just open any of the airfoil files included with HARP_Opt and replace the data with your own airfoil data (text file editor, or copy-pa...
by Danny.Sale
Mon Mar 13, 2017 3:48 pm
Forum: Tidal Current
Topic: HARP_opt help on hydrokinetic turbine
Replies: 5
Views: 4159

Re: HARP_opt help on hydrokinetic turbine

hi Yao, I would check the content of the pUvars variable. This is related to the velocity probability distribution, maybe there is some mistake such that size of pUvars is incorrect. Or the V and PWR dimensions are not consistent for some reason. It's good you are running in Matlab, you can use the ...
by Danny.Sale
Wed Mar 08, 2017 9:37 am
Forum: Tidal Current
Topic: HARP_opt help on hydrokinetic turbine
Replies: 5
Views: 4159

Re: HARP_opt help on hydrokinetic turbine

hello Yao Wang, I think the difficulty is related to cavitation. First attempt to disable the cavitation option, and hopefully that works. But there are several ways to change the design so cavitation is less likely; there is some other discussion about cavitation on the forums here: https://wind.nr...
by Danny.Sale
Wed Mar 08, 2017 9:28 am
Forum: Tidal Current
Topic: Harp_opt help
Replies: 19
Views: 13159

Re: Harp_opt help

hi Rubén, The part of the error message that I suspect is important is: Error using .* Matrix dimensions must agree. Error in calcAEP (line 29) avgPwr = trapzf(VEL, pwr.*VEL_DIST); and I wonder if pwr and VEL_DIST are the same size. VEL_DIST is the velocity probability distribution, and is defined w...
by Danny.Sale
Wed Mar 08, 2017 8:57 am
Forum: Computer-Aided Engineering Software Tools
Topic: HARP Opt Error Troubleshooting
Replies: 1
Views: 612

Re: HARP Opt Error Troubleshooting

hi Gavin, Because you are designing a blade with circular root section, you should also give additional airfoil file for the "circle". And then set ThickVals = 100 14, where the 100 refers the 100 % thickness airfoil. The code is then going to blend between the circular airfoil and NACA 14...
by Danny.Sale
Fri Aug 12, 2016 5:37 pm
Forum: Tidal Current
Topic: Harp_opt help
Replies: 19
Views: 13159

Re: Harp_opt help

hello, did you manage to resolve this problem related to the errors in optAero.m and optFitness.m? I checked it today and uploaded a quick bugfix to GitHub, maybe this resolves the error you received. It sounds like you ran the 'test_VSFP.inp' example ... it worked for me now without error, let me k...
by Danny.Sale
Fri Aug 12, 2016 5:07 pm
Forum: Tidal Current
Topic: Harp_opt help
Replies: 19
Views: 13159

Re: Harp_opt help

hi Ruben,

Which optimization method did you use, and are you running the multiple objective mode (which adds the structural objective)? And are you saying that the data in the *.xls spreadsheet is different than the data in the corresponding WT_Perf input file?

thanks,
Danny
by Danny.Sale
Fri Aug 12, 2016 3:46 pm
Forum: Computer-Aided Engineering Software Tools
Topic: HARP_Opt help with structural optimization
Replies: 2
Views: 1015

Re: HARP_Opt help with structural optimization

hi Maria, were you able to figure this out? My first thought is to check the format of the *.prof files, which have the x-y coordinates of the airfoils. Check if the order of points goes clockwise or counter-clockwise around the airfoil (I think it should be clockwise). Also I think the first and la...
by Danny.Sale
Mon Nov 02, 2015 12:07 pm
Forum: Tidal Current
Topic: Harp_opt help
Replies: 19
Views: 13159

Re: Harp_opt help

Hi Mujahid,

it appears you are using directory names containing "spaces", Matlab has some trouble with this sometimes. Try renaming "Acer pc" to something like "Acer_pc", this is what the Matlab error is indicating.

~Danny
by Danny.Sale
Wed Oct 14, 2015 3:04 pm
Forum: Tidal Current
Topic: Harp_opt help
Replies: 19
Views: 13159

Re: Harp_opt help

Hi Mujahid, maybe first try decreasing tolerance and increasing maximum iterations (and next maybe change TI_SINGULARITY or other parameters) within the section labeled "BEMT Options" ... and if that cannot help then HARP_Opt v2 does not recognize the WT_Perf error. And then I suggest tryi...
by Danny.Sale
Wed Oct 14, 2015 2:46 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Announcing release of HARP_Opt code
Replies: 9
Views: 9550

Re: Announcing release of HARP_Opt code

Hi Monika, you are correct the error is probably about not having Excel installed. Fortunately, v3 of HARP_Opt alleviates many of the toolboxes and dependencies that v2 required. Hopefully you can try it and it solve your trouble, the newest Matlab version is here: https://github.com/NREL/HARP_Opt a...

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