Search found 34 matches

by Yanhua.Liu
Wed Apr 04, 2018 11:03 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Nope, I think that the inverse MBC is right. I found something is wrong with my linearization results. I linearized the NREL 5MW wind model at 18m/s with two DOFs like Generator DOF and 1st blade flapwise bending DOF (using Test18.fst). The inputs used are three individual pitch angles a...
by Yanhua.Liu
Mon Apr 02, 2018 10:41 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Sorry for the delay. Yep, I have applied the inverse MBC to the individual blade bending moments and also the cosine and/or sine terms are nonzero. The blade bending moments did not show any periodicity in 1P after inverse MBC. I tried another linearization by adding tower DOFs. But the ...
by Yanhua.Liu
Wed Mar 28, 2018 8:51 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Thank you so much for your quick email response and answer. Actually, I have applied inverse MBC to the linear model. The figure is after inverse MBC transformation. Does this mean the linear model is not so exact and have some accuracy problem? Thank you again and all the best to you. Y...
by Yanhua.Liu
Wed Mar 28, 2018 4:43 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Thanks for your time. Actually, I found something wrong about the linearization result. If we eliminate the generator-azimuth state in the linearized state-space model, the flapwise bending moment from linearization will lose the periodicity just as the red line shown in the Fig. 1 I att...
by Yanhua.Liu
Tue Jan 23, 2018 12:42 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Confusions about Compiling FAST
Replies: 6
Views: 2276

Re: Confusions about Compiling FAST

Dear Jason,

Thanks a lot. It is much more clear to me.

All the best.

Yanhua
by Yanhua.Liu
Tue Jan 23, 2018 8:55 am
Forum: Computer-Aided Engineering Software Tools
Topic: Confusions about Compiling FAST
Replies: 6
Views: 2276

Re: Confusions about Compiling FAST

Dear Jason, Thanks a lot. It seems like SOWFA are better to me before FAST.Farm releases. I still have some confusions. Does SOWFA provide outputs of structural loads? Is it possible for us to change the individual wind turbine parameters in SOWFA? Does FLORIS, SOWFA or FAST.Farm provide interface t...
by Yanhua.Liu
Tue Jan 23, 2018 5:50 am
Forum: Computer-Aided Engineering Software Tools
Topic: Confusions about Compiling FAST
Replies: 6
Views: 2276

Re: Confusions about Compiling FAST

Dear Jason, Thanks for your timely answer. If I want to define a wind turbine model of 3.6MW, should I need to change the input parameters in Test18.fst and the related ElastoDyn.dat, BeamDyn.dat,InflowWind_12mps.dat,AeroDyn15.dat,ServoDyn.dat? Actually, I want to do some research about designing co...
by Yanhua.Liu
Mon Jan 22, 2018 8:16 am
Forum: Computer-Aided Engineering Software Tools
Topic: Confusions about Compiling FAST
Replies: 6
Views: 2276

Confusions about Compiling FAST

Hi all, I am trying to do some research on the wind farm. Firstly, I want to do research on a specific 3.6MW wind turbine. If I have all the data about the specific 3.6MW wind turbine, can I change the parameters of the NREL 5MW wind turbine into the wind turbine I wanted? Does compiling FAST realiz...
by Yanhua.Liu
Fri Sep 22, 2017 4:17 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Thanks a lot. When I eliminate the generator-azimuth state, it is exactly what I want. However, how to understand MBC_NaturalFrequency and MBC_DampingRatio? How to obtain the information of a rigid-body mode associated with the generator-aximuth state from MBC_NaturalFrequency and MBC_Da...
by Yanhua.Liu
Thu Sep 21, 2017 4:16 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Actually no. I tried both FAST V7 and FAST V8. I found they both have this problem. I attached the GetMats.m, mbc3.m, my linearization result (4 DOFs: generator DOF, 1st flapwise) and other related procedures. Can you spare me some time? Can you help me to check it, please? I changed mbc...
by Yanhua.Liu
Wed Sep 20, 2017 11:46 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Yes, It indeed has the above problem. Sorry for the faults. I changed them. It seems reasonable now for 3 DOFs. But the problem still exists for 4 DOFs including the generator DOF. I checked my simulation and I don't think something is wrong with it. linearmodel_4DOF.jpg But the state (r...
by Yanhua.Liu
Tue Sep 19, 2017 11:11 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Yes, I am really confused about this, but it is indeed unstable. This is what I used for the time-domain solution. Linearized model.jpg Linearized model 1.jpg I give "Pitch angle step" a step input then obtain the unstable results. Can you help me check it, please? Thank you so...
by Yanhua.Liu
Tue Sep 19, 2017 10:10 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Hi Jason, I tried only using three DOF (1st flapwise blade mode), but the result is not so good. The states xfl0, xflc,xfls are all unstable like this: xfl0.jpg I attached my linearized file, can you help me check it, please? I feel really desperate about my result. I really appreciate your kind hel...
by Yanhua.Liu
Mon Sep 18, 2017 11:06 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Your understanding is correct except that there 4 DOFs (Generator DOF and First flapwise blade mode DOF) and 4 outputs (rotor speed and 3 flapwise bending moments). I am using FAST V7 for linearization. My linearization is done under wind speed 18m/s without any vertical shear. In this o...
by Yanhua.Liu
Sat Sep 16, 2017 6:39 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST linearization V7
Replies: 25
Views: 6762

Re: FAST linearization V7

Dear Jason, Thanks for all your help. Actually, I still have the problem that the output of flapwise bending moment from the linearized model (after MBC) is increasing slowly with time. I tried using 3 DOFs only the first flapwise blade mode of each blade and the result is same. You know, the 3 outp...

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