Search found 66 matches

by Cheng.Zhang
Thu Apr 02, 2020 4:16 pm
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason, I used individual blade pitch (IBP) control reduced the 1p load of blade root flap-wise moment, and plotted its PSD as you see in Figure 1 and Figure 2. The simulations are made by FAST OC3Hywind model with all DOFs enabled, Figure 1 shows the PSD results of constant wind and no wave; Fi...
by Cheng.Zhang
Wed Mar 18, 2020 3:02 pm
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason,

Thank you very much for your patience and answers, it is very helpful for me!

Best regards,
Cheng
by Cheng.Zhang
Wed Mar 18, 2020 1:12 pm
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason, I used the NRELOffshrBsline5MW_OC3Hywind model. The _MAP.dat file is as following ---------------------- LINE DICTIONARY --------------------------------------- LineType Diam MassDenInAir EA CB CIntDamp Ca Cdn Cdt (-) (m) (kg/m) (N) (-) (Pa-s) (-) (-) (-) Material 0.09 77.7066 384.243E6 ...
by Cheng.Zhang
Wed Mar 18, 2020 12:06 pm
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason, Thank you. From Figure 2. How to explain that the STD of mooring line fair-lead force and anchor force reduced with increased roll and yaw rate. What kind of motions affects the force of mooring lines? I didn't find the analysis of mooring lines in the literature, but my colleague in the...
by Cheng.Zhang
Wed Mar 18, 2020 11:35 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason,

Figure 1 and Figure 5 show the conclusions as you said.
Sorry, I still don't know if the DEL of the tower base is reasonable or not... :oops:

Best regards,
Cheng
by Cheng.Zhang
Wed Mar 18, 2020 10:56 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason, Thank you for your FAST reply. Yes, I agree with you that IBP increase the platform roll and yaw motion However, what I am not sure of is that the tower base side-to-side DEL is decreased even the roll motion increased. Yaw motion increased significantly, but the torsional DEL increased ...
by Cheng.Zhang
Wed Mar 18, 2020 9:50 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason, I made some simulations using IBP control, I check the RMS of platform motion, DEL of tower base bending moment and DEL of blade flap-wise bending moment, but I'm not sure my simulation results are reasonable. You can find the results in the closed file, and I made some comparisons betwe...
by Cheng.Zhang
Thu Nov 21, 2019 6:44 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST8 Build Model problems
Replies: 3
Views: 1069

Re: FAST8 Build Model problems

Dear Bonnie, Thank you for your reply. I didn't make any change the include path of creat_FAST_SFunc.c. I know that I can use creat_FAST_SFunc.c to generate the .mexw64 file. I don't know if I well understand what you said, my understanding is: If I want to use the creat_FAST_SFunc.c to built model ...
by Cheng.Zhang
Wed Nov 20, 2019 5:49 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST8 Build Model problems
Replies: 3
Views: 1069

FAST8 Build Model problems

Dear all, I want to make a connection between the SIMULINK FAST nonlinear model and DSpace. I need to Build Model in the SIMULINK, but when I went to this step, the following errors appear. COMPILING "..\FAST_SFunc.c" In file included from C:/PROGRA~1/Matlab/R2012b/extern/include/mex.h:58,...
by Cheng.Zhang
Wed Oct 30, 2019 7:29 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason,

I appreciate your help, my last question is, is there any link between the FlapDOF1 and blade root flap-wise bending moment?

Best regards,
Cheng
by Cheng.Zhang
Wed Oct 30, 2019 3:49 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason. Thank you. Actually, no matter which index I use. I think the inputs of IBP controller have the following options, I don't know which one is better 1. The variation (with respect to an operating point) of the blade root moments; the control objective is to reduce such variation to zero ....
by Cheng.Zhang
Tue Oct 29, 2019 11:01 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Re: Fatigue load reduction of bldae

Dear Jason, Thank you for your fast reply. I remembered I asked you a similar question about the fatigue load evaluation in this forum https://wind.nrel.gov/forum/wind/viewtopic.php?f=30&t=2004&start=45 . I only have a single time series of results, you recommend me to use STD or RMS of mome...
by Cheng.Zhang
Tue Oct 29, 2019 7:01 am
Forum: Controls
Topic: Fatigue load reduction of bldae
Replies: 20
Views: 2276

Fatigue load reduction of bldae

Dear all, I have a question about the reduction of blade fatigue load. As far as I know, I can use individual blade pitch control to reduce the blade load. In order to design the controller, I need the information of blade flap-wise root moments. The question is, if I want to reduce the fatigue load...
by Cheng.Zhang
Thu Sep 26, 2019 3:12 am
Forum: Structural Analysis
Topic: load of mooring line
Replies: 2
Views: 1254

Re: load of mooring line

Dear Jason,

Thank you!
I found that T and T_a in the outlist represent fairlead force and anchor force respectively. It is always there, but I never take notice of them... :oops:

Best regards,
Cheng
by Cheng.Zhang
Wed Sep 25, 2019 10:44 am
Forum: Structural Analysis
Topic: load of mooring line
Replies: 2
Views: 1254

load of mooring line

Hello,

Could anyone tell me how to get loads of the mooring lines from FAST 8 ?
The model I used is OC3Hywind, I didn't find any information about the mooring line load from the User's Guide.

Many thanks,
Cheng

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