Search found 15 matches

Fri Sep 23, 2011 9:26 am
Forum: Computer-Aided Engineering Software Tools
Topic: Resistant moment of the rotor and of the electric generator
Replies: 9
Views: 11240

Resistant moment of the rotor and of the electric generator

Hi, I'd like to know if you have the values of the rotational frequency of the rotor blades (rot_freq) in function of the mean wind speed at the hub (Um_hub) and of the aerogenerators that you test for exemples in FAST. Is it possible also to have the trend of the resistant angular momentum in funct...
Mon Sep 19, 2011 4:33 am
Forum: Computer-Aided Engineering Software Tools
Topic: Damping of the rotor blades
Replies: 14
Views: 7889

Re: Damping of the rotor blades

Dear Jason,

thanks for your help. Do the natural frequencies also come from the centrifugal force due the rotation of the blade (geometrical component of the blade stiffness) ?

Thanks a lot, best regards

Lorenzo
Fri Sep 16, 2011 3:40 am
Forum: Computer-Aided Engineering Software Tools
Topic: Damping of the rotor blades
Replies: 14
Views: 7889

Dear all, I'd like to know your opinio about the damping of the rotor ? In my model i build the damping matrix (C) through the Rayleigh's method for which the damping matrix C is function of the mass and stiffness matrices. Do you think that to evaluate C i have to consider also the geometric stiffn...
Thu Sep 08, 2011 11:59 am
Forum: Computer-Aided Engineering Software Tools
Topic: Normal aerodynamic forces on the tower
Replies: 15
Views: 9166

Re: Normal aerodynamic forces on the tower

Dear Jason, thanks for your support, best regards

Lorenzo
Thu Sep 08, 2011 4:12 am
Forum: Computer-Aided Engineering Software Tools
Topic: Normal aerodynamic forces on the tower
Replies: 15
Views: 9166

Re: Normal aerodynamic forces on the tower

Hi, thanks for your helps! To evaluate the along-wind wind loading, Frot/nac, acting on the hub/nacelle of a upwind wind turbine with rotor plane perpendicular to the wind direction, i think that can be used the formula: Frot/nac=0.5*Cd_rot*d_air*(Umean+Ufluct)^2*A where Cd_rot is the draf coefficie...
Fri Aug 26, 2011 10:31 am
Forum: Computer-Aided Engineering Software Tools
Replies: 2
Views: 1116

Dear Jason, i thank you for your help; You clarified me! Best regards,

Lorenzo Montanari
Fri Aug 26, 2011 2:41 am
Forum: Computer-Aided Engineering Software Tools
Replies: 2
Views: 1116

Hi all, I'd like to have this information. FAST takes in account the dynamic interaction between the dynamic responses of the blades and the tower ? In other words, the system Tower/Blades is coupled or uncoupled ? Again, in FAST, the dynamic response of the blades is function of the tower-top accel...
Tue Aug 09, 2011 9:05 am
Forum: Computer-Aided Engineering Software Tools
Topic: Normal aerodynamic forces on the tower
Replies: 15
Views: 9166

Re: Normal aerodynamic forces on the tower

Dears, In upwind conditions, do you know how modelling the influence of the blades passing in the wind loading acting on the tower ? I didn't find papers in literature. Should i use the same theory law that i consider to simulate the "tower shadow" effect on the blades (in upwind condition...
Tue Aug 09, 2011 8:51 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST Output
Replies: 3
Views: 1345

Re: FAST Output

Dear Buhl Marshall,

I thank for your response. I got wrong: the correct words are "eigenvalues matrices" and "eigenvectors matrices".

Thanks again.

Lorenzo
Fri Jul 22, 2011 10:19 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST Output
Replies: 3
Views: 1345

FAST Output

Dears, To compare the results that i get from my MATLAB model with FAST results I'd like to have other outputs. For exemples: - the blades element forces time history (e.g. at the tip); - the mass, stiffness, autovector matrices - autoval vector. Is possibile to know (stamp) these parameters ? I tha...
Fri Jul 15, 2011 10:35 am
Forum: Rotor Aerodynamics
Topic: BEM method Implementation
Replies: 3
Views: 13711

Re: BEM method Implementation

Dear Marshall Buhl, I have read the paper you suggest to me; and I have insert in my Matlab program the sine curve singularity transition model but still it doesn't converge? The problem is with low wind speed. If i have correctly understood with that modification now the your program converge alway...
Tue Jul 12, 2011 10:53 am
Forum: Rotor Aerodynamics
Topic: BEM method Implementation
Replies: 3
Views: 13711

BEM method Implementation

Dear, I'm writing a Wind Generators FE model in Matlab. I'm implementing the BEM model you suggest in the AaeroDyn Theory Manual. I use the Tip-Loss Model, the Hub-Loss Model and the Buhl Correction for evaluate the axial induction factor (a) when CT (thrust coefficient) >0.96*F. I don't consider th...
Thu Jul 07, 2011 12:23 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Normal aerodynamic forces on the tower
Replies: 15
Views: 9166

Re: Normal aerodynamic forces on the tower

Dear Marshall Buhl

i'm really grateful for your support, best regards

Lorenzo Montanari
Wed Jul 06, 2011 2:00 am
Forum: Computer-Aided Engineering Software Tools
Topic: Normal aerodynamic forces on the tower
Replies: 15
Views: 9166

Re: Normal aerodynamic forces on the tower

Dear Marshall Buhl, could you send me the geometrical and the mechanical data of the tower of the 1,5 MW wind turbine you modelled ? I'd need to know the radius at the nodal sections (if the section is circular) or the geometrical data (if the section has a polygonal shape) Usually, which drag coeff...
Tue Jul 05, 2011 10:17 am
Forum: Computer-Aided Engineering Software Tools
Topic: Normal aerodynamic forces on the tower
Replies: 15
Views: 9166

Normal aerodynamic forces on the tower

Hi all, I'm Lorenzo Montanari, a PhD student of the University of Parma (Italy). I'm checking the wind turbine model, i'm writing in MATLAB language, with FAST. I'm considering the data of the 1.5 MW wind turbine you used to verify FAST. I don't find the data file to insert the drag coefficient and ...