Search found 11 matches

by Albert.Meseguer
Thu Aug 25, 2016 5:55 am
Forum: AeroDyn Development
Topic: Dynamic Stall Theory and Implementation
Replies: 18
Views: 19953

Re: Dynamic Stall Theory and Implementation

Hi everyone, I have been reading the theory behind the different dynamic stall parameters and I'm a little bit confused about the definiton of alpha0 for the NACA64_A17.dat of the 5MW reference turbine. The value defined in the provided airfoil is -4.432. However It does not match with the provided ...
by Albert.Meseguer
Wed Aug 24, 2016 2:40 am
Forum: Rotor Aerodynamics
Topic: Wake-Skewed Angle Model
Replies: 8
Views: 7322

Re: Wake-Skewed Angle Model

Dear Jason, Thank you for your fast reply. In both simulations the inflow-skew angle is 0 in all the simulation (as expected) . I took a look into the aerodynamic parameters you mentioned in your post , for nodes close to the root both induction factors (B1N1AxInd , B1N1TnInd) are the same. Therefor...
by Albert.Meseguer
Tue Aug 23, 2016 4:02 am
Forum: Rotor Aerodynamics
Topic: Wake-Skewed Angle Model
Replies: 8
Views: 7322

Wake-Skewed Angle Model

Hi everyone, I am running some simulations where I compare the effect of the two available skewed-wake correction model in Aerodyn v15.03 (Uncoupled and Pitt and Peters model) . My case presents a wind turbine with no tilt neither blade pre-cone. I use an uniform wind speed without shear effect. Equ...
by Albert.Meseguer
Mon Aug 22, 2016 12:31 am
Forum: Rotor Aerodynamics
Topic: Pure Aerodynamic Force Discrepancies
Replies: 8
Views: 4397

Re: Pure Aerodynamic Force Discrepancies

Dear Jason,

I reduced the time step to half of what I was having before ( I'm using now 0.005) and I get same magnitude of the error.
It seems I was using a big time step.

Thank you for your response and explanation.
by Albert.Meseguer
Fri Aug 19, 2016 12:20 am
Forum: Rotor Aerodynamics
Topic: Pure Aerodynamic Force Discrepancies
Replies: 8
Views: 4397

Re: Pure Aerodynamic Force Discrepancies

Dear Jason,

It randomly matches. I only post a part of the simulation.

I plot the complete time-series and the relative error now.

Error_RotThrust.png
Error_RotThrust.png (54.68 KiB) Viewed 4361 times



Thank you for your support.
by Albert.Meseguer
Thu Aug 18, 2016 7:09 am
Forum: Rotor Aerodynamics
Topic: Pure Aerodynamic Force Discrepancies
Replies: 8
Views: 4397

Re: Pure Aerodynamic Force Discrepancies

Hi again Jason , I ran now a turbulent time series ( same conditions as before ) and compare the two parameters. Turbulent_image.png Is there any dynamics involved between the two FAST outputs? I am a bit confused why they are not the same value considering there is not pre-cone neither tilt. Any id...
by Albert.Meseguer
Wed Aug 17, 2016 1:27 am
Forum: Rotor Aerodynamics
Topic: Pure Aerodynamic Force Discrepancies
Replies: 8
Views: 4397

Re: Pure Aerodynamic Force Discrepancies

Dear Jason,

I have upgraded to the new FAST version and run the same case :

new_fig_r.PNG
new_fig_r.PNG (38.38 KiB) Viewed 4380 times


It seems correct to me now !

Thank you for your support.
by Albert.Meseguer
Tue Aug 16, 2016 1:53 am
Forum: Rotor Aerodynamics
Topic: Pure Aerodynamic Force Discrepancies
Replies: 8
Views: 4397

Pure Aerodynamic Force Discrepancies

Hi everybody, I am facing some problems when comparing the thrust forces “RotThrust” and “RtAeroFxh” . My model is a simplification of the 5MW onshore reference wind turbine where no pre-cone neither tilt is applied (both set to zero). All my DOF of the turbine are FALSE except the generator DOF. I ...
by Albert.Meseguer
Wed Feb 24, 2016 9:52 am
Forum: Structural Analysis
Topic: 6x6 Stiffness Matrix of NREL5 MW Turbine
Replies: 25
Views: 9656

Re: 6x6 Stiffness Matrix of NREL5 MW Turbine

Dear Jason, I have read an old post where it is stated that ( in older versions) the blade assumes zero offset of elastic and shear center. Does the new BeamDyn module consider a possible offset of shear and elastic center? I do not see in the 5MW reference model any information about that. Thank yo...
by Albert.Meseguer
Wed Feb 24, 2016 3:39 am
Forum: Structural Analysis
Topic: 6x6 Stiffness Matrix of NREL5 MW Turbine
Replies: 25
Views: 9656

Re: 6x6 Stiffness Matrix of NREL5 MW Turbine

Hi Jason, Thank you for your response. Based on the link you attached , It is more clear the direction of the blade local coordinate system. However I am still a little bit confused how the center coordinate is defined in BeamDyn. Let's imagine we have a completly straight blade where kp_x and kp_y ...
by Albert.Meseguer
Tue Feb 23, 2016 1:53 pm
Forum: Structural Analysis
Topic: 6x6 Stiffness Matrix of NREL5 MW Turbine
Replies: 25
Views: 9656

Re: 6x6 Stiffness Matrix of NREL5 MW Turbine

Hi NREL team & others, I am modelling the 5MW reference W.T. turbine using another aeroelastic software. I have to include offset. It is mentioned in previous entrances that Test 26 includes the edgewise sectional C.G. offset. It is not clear to me how this is included. I assume it should be def...

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