Search found 14 matches

by Vahid.Jahangiri
Tue Mar 02, 2021 8:12 pm
Forum: Structural Analysis
Topic: Wind turbine blade sectional moment of area
Replies: 1
Views: 574

Wind turbine blade sectional moment of area

Dear Jason, I am doing a structural analysis on wind turbine blades and I need some information regarding the blade dimensions. I was wondering what is the value for sectional moment of area at the root of wind turbine blade for an NREL 5MW. Also, having the outer and inner radius can help(Cylinder1...
by Vahid.Jahangiri
Sun Jul 26, 2020 1:45 am
Forum: Structural Analysis
Topic: Spar heave frequency spectrum
Replies: 6
Views: 1813

Re: Spar heave frequency spectrum

Dear Jason, Following up with my question, to ensure that my developed model is valid. I run FAST for OC3 Hywind with Moordyn. The attached picture shows my heave response in frequency domain and as you can see the natural frequency of the Spar in heave direction is the dominant frequency (0.034 Hz)...
by Vahid.Jahangiri
Thu Jul 23, 2020 10:41 am
Forum: Structural Analysis
Topic: Spar heave frequency spectrum
Replies: 6
Views: 1813

Re: Spar heave frequency spectrum

Dear Jason,

Thank you so much for your clear explanation.
FYI, my spar model design is the OC3 Hywind.
by Vahid.Jahangiri
Thu Jul 23, 2020 9:34 am
Forum: Structural Analysis
Topic: Spar heave frequency spectrum
Replies: 6
Views: 1813

Re: Spar heave frequency spectrum

Dear Jason, Thank you so much for your quick response, it really helps. What about the dominant natural frequency? As you can see the frequency of the surge is more dominant than heave natural frequency itself. Is this OK? Also, are we expecting to see wave frequency in heave direction? I don't see ...
by Vahid.Jahangiri
Wed Jul 22, 2020 7:53 pm
Forum: Structural Analysis
Topic: Spar heave frequency spectrum
Replies: 6
Views: 1813

Spar heave frequency spectrum

Dear Jason, I have developed a MATLAB code to numerically model a spar type floating wind turbine. I am trying to understand its dynamic responses. When I take the FFT of my time domain responses, I clearly see that the natural frequency of the structure in Surge and tower fore-aft direction can be ...
by Vahid.Jahangiri
Tue Jul 24, 2018 5:44 pm
Forum: Structural Analysis
Topic: OC3 Hywind Structural Properties
Replies: 4
Views: 4500

Re: OC3 Hywind Structural Properties

Dear Jason,

Thank you for your response, probably there should be a mistake in another place and I need to check and see why my frequency in pitch and roll DOFs do not agree with the ones in literature.
thank you
by Vahid.Jahangiri
Mon Jul 23, 2018 5:34 pm
Forum: Structural Analysis
Topic: OC3 Hywind Structural Properties
Replies: 4
Views: 4500

Re: OC3 Hywind Structural Properties

Dear Jason, Thanks for your complete response. Yes ^2 for M_t is a typo in my equations and I have mistakenly considered the system CG to be located at -89.9155. Even, changing the h value to 78 m does not help me find the correct frequencies in roll and pitch directions. I believe my calculations f...
by Vahid.Jahangiri
Fri Jul 20, 2018 4:20 pm
Forum: Structural Analysis
Topic: OC3 Hywind Structural Properties
Replies: 4
Views: 4500

OC3 Hywind Structural Properties

Hi, I am trying to model OC3 Spar FWT with 14 DOFs (6DOF for blades, 2 for tower, 6 for platform). The frequencies of the translational motion agrees with frequencies provided in literature (Surge= Sway = 0.008, Heave = 0.0324). However, I don't get the correct frequencies in roll and pitch degrees ...
by Vahid.Jahangiri
Mon Jun 27, 2016 3:50 am
Forum: Computer-Aided Engineering Software Tools
Topic: Installing FAST
Replies: 3
Views: 4463

Re: Installing FAST

Thanks for your reply. I did all the things written there but still I get this error!

Fast encountered an error during module initialization.
Simulation error level: FATAL ERROR
Aborting FAST
by Vahid.Jahangiri
Fri Jun 24, 2016 5:07 am
Forum: Computer-Aided Engineering Software Tools
Topic: Installing FAST
Replies: 3
Views: 4463

Installing FAST

Hello I read most of the topics created here. But I couldn't find my answer. The questions were more complicated and I have problem in my first step. I have downloaded FAST8 from this link: https://nwtc.nrel.gov/FAST8 Then I have read the tutorial from here: https://nwtc.nrel.gov/system/files/Setup_...
by Vahid.Jahangiri
Wed Jan 28, 2015 12:47 pm
Forum: Structural Analysis
Topic: Spring controllers in the joint between tower and nacelle
Replies: 7
Views: 5447

Re: Spring controllers in the joint between tower and nacell

Dear Jason
Thanks for your guidance. It is NREL TLP supporting 5MW NREL turbine. The one mentioned in the attached file. but only the properties are the same and my model is a new model with large amplitude motion. I want the natural frequency of the tower-bending mode to validate my work
by Vahid.Jahangiri
Wed Jan 28, 2015 2:40 am
Forum: Structural Analysis
Topic: Spring controllers in the joint between tower and nacelle
Replies: 7
Views: 5447

Re: Spring controllers in the joint between tower and nacell

Dear Jason

I have searched through various papers to find the natural frequency of Nrel 5 MW nacelle and I couldn't find it. Do you know what are the frequencies of the nacelle?
by Vahid.Jahangiri
Mon Dec 22, 2014 1:04 pm
Forum: Structural Analysis
Topic: Spring controllers in the joint between tower and nacelle
Replies: 7
Views: 5447

Re: Spring controllers in the joint between tower and nacell

Dear Jason

I have uploaded an image that is for Gireesh paper which I have taken from "http://www.iwwwfb.org/Abstracts/iwwwfb26/iwwwfb26_37.pdf" . My model is something like this but not exactly this type. I hope this could help.

Thank you
Vahid Jahangiri
by Vahid.Jahangiri
Mon Dec 22, 2014 9:47 am
Forum: Structural Analysis
Topic: Spring controllers in the joint between tower and nacelle
Replies: 7
Views: 5447

Spring controllers in the joint between tower and nacelle

Hello I have modeled a Floating wind turbine in matlab with multibody dynamics formulas. In the joint where the tower and nacelle are connected to each other I have modeled some control equations with spring-damper in the roll and pitch rotations of nacelle(yaw direction is free and has no control e...

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