Search found 45 matches

by KumaraRaja.Eedara
Sun Dec 08, 2019 12:05 am
Forum: Structural Analysis
Topic: Rotor Inertia computation
Replies: 4
Views: 970

Re: Rotor Inertia computation

Thanks, Jason. For the benefit of others, here is the formula for the p%RNodes: (Line 2432, ElastoDyn.F90 source file) p%RNodes = BladeMeshData(K)%RNodes - p%HubRad ! Radius to blade analysis nodes relative to root ( 0 < RNodes(:) < p%BldFlexL ) (Convert RNodes to be relative to the hub) Regards, Ku...
by KumaraRaja.Eedara
Mon Dec 02, 2019 11:35 am
Forum: Structural Analysis
Topic: Rotor Inertia computation
Replies: 4
Views: 970

Re: Rotor Inertia computation

Dear Jason, Thanks for the clarification. It checks out now. For RNode definition, I looked at the picture (below) and mistook as the distance from the rotor axis. Bladelayout.JPG Instead I should have referred to the definition given in the later part of the FAST documentation as: RNodes These valu...
by KumaraRaja.Eedara
Sun Dec 01, 2019 4:54 am
Forum: Structural Analysis
Topic: Rotor Inertia computation
Replies: 4
Views: 970

Rotor Inertia computation

Dear all, This question is regarding the rotor inertia reported in ElastoDyn summary file. And its computation. I have taken the below formula01 and 02 from the ElastoDyn Source Code. Variable K stands for the blade number; Formula01 : Blade Inertia Formula: (Line:4747) p%SecondMom(K) = p%SecondMom(...
by KumaraRaja.Eedara
Fri Nov 29, 2019 1:46 pm
Forum: Controls
Topic: Blade pitch control
Replies: 26
Views: 9605

Re: Blade pitch control

Dear all, I am trying to implement a simple pitch controller in FAST using MATLAB (Simulink). However, I observe discrepancy in the pitch angle between MATLAB and FAST.out. Kindly note that here i am not using two different controllers in FAST and MATLAB. I am simply setting PCMode to 4 in servodyn....
by KumaraRaja.Eedara
Sat Oct 05, 2019 11:10 am
Forum: Inflow Turbulence
Topic: Rotationally sampled wind
Replies: 2
Views: 1127

Re: Rotationally sampled wind

Dear Jason,

I was talking about "Wind1VelX". Thanks for the clarification.

Regards,
Kumara
by KumaraRaja.Eedara
Sat Oct 05, 2019 3:55 am
Forum: Inflow Turbulence
Topic: Rotationally sampled wind
Replies: 2
Views: 1127

Rotationally sampled wind

Dear all, After performing simulation (with turbsim generated wind file *.bts as input) in FAST, I've extracted the wind velocities (Vx, Vy, Vz) from the .out file generated by FAST. Is this rotationally sampled wind ? or Eulerian wind measurement (i.e wind measured at an inertial location) ? My und...
by KumaraRaja.Eedara
Sat Jul 20, 2019 9:15 am
Forum: Rotor Aerodynamics
Topic: Difference in the torque value computed from tangential forces and RotTorque output from Elastodyn_BDoutputs file
Replies: 10
Views: 5073

Re: Difference in the torque value computed from tangential forces and RotTorque output from Elastodyn_BDoutputs file

Dear Jason, I have written Matlab code for calculating aerodynamic forces; I am comparing with the FAST results ( AeroDynV15 used). I have NOT accounted for induction factors in my code. For a uniform wind speed case, I see good correlation between my results and FAST results, in rotor speed, alpha,...
by KumaraRaja.Eedara
Fri Jul 19, 2019 11:21 pm
Forum: Computer-Aided Engineering Software Tools
Topic: AeroDyn error
Replies: 12
Views: 3573

Re: AeroDyn error

Thanks for pointing that out Jason. I forgot to set "CompAero" to 2.

Regards,
Kumara
by KumaraRaja.Eedara
Fri Jul 19, 2019 2:23 pm
Forum: Computer-Aided Engineering Software Tools
Topic: AeroDyn error
Replies: 12
Views: 3573

Re: AeroDyn error

Dear all, I am able to run a simulation without any errors using AeroDynV14, when i replace it with AeroDynV15 I see the following error. Attached AerodynV15 file I'm using. FAST_InitializeAll:ED_Init:ED_ReadInput:ReadBladeInputs:ReadBladeMeshFileAD:Invalid numerical input for file "E:\FAST\Wor...
by KumaraRaja.Eedara
Wed Jul 17, 2019 12:28 am
Forum: Computer-Aided Engineering Software Tools
Topic: Creating wind speed without turbulent
Replies: 5
Views: 2164

Re: Creating wind speed without turbulent

Thanks, Jason. The post mentioned below from https://wind.nrel.gov/forum/wind/viewtopic.php?f=4&t=908&p=4229 is really helpful. Dear Yiqing, For simple wind time histories, such as step changs in the wind speed, AeroDyn's simple "hub-height" format wind data file can be used in pla...
by KumaraRaja.Eedara
Tue Jul 16, 2019 2:29 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Creating wind speed without turbulent
Replies: 5
Views: 2164

Re: Creating wind speed without turbulent

Dear Jason, I want to create a uniform wind (i.e same wind speed across the disk) and also constant with respect to time. To create uniform wind file I've selected 2 for 'wind type' in "InflowWind.dat". This requires '***.hh' as input right? As per my understanding AeroDynV13 has this opti...
by KumaraRaja.Eedara
Tue Jul 16, 2019 8:28 am
Forum: Rotor Aerodynamics
Topic: AeroDyn v.14 (VT, CNN, CTT)
Replies: 8
Views: 5344

Re: AeroDyn v.14 (VT, CNN, CTT)

Thanks, Jason. That was oversight from my side. I've attached figure here for making it more easy to see. The output is written to a file "filename.AD.out".
AerodynV14_PrntOutput.JPG
AerodynV14_PrntOutput.JPG (175.18 KiB) Viewed 1794 times


Regards,
Kumara
by KumaraRaja.Eedara
Tue Jul 16, 2019 5:46 am
Forum: Rotor Aerodynamics
Topic: AeroDyn v.14 (VT, CNN, CTT)
Replies: 8
Views: 5344

Re: AeroDyn v.14 (Output channels)

Dear all,

I'm using AeroDyn v.14.. Is it possible to print the outputs of aerodynamic quantities like angle of attack, lift coefficient etc at each airfoil section. It seems possible in AeroDyn v.15 . But is it possible using v.14? If yes, how? Thanks.

Regards,
Kumara
by KumaraRaja.Eedara
Mon Jul 15, 2019 1:14 am
Forum: Controls
Topic: questions about reference control input
Replies: 61
Views: 19457

Re: questions about reference control input

Thanks, Jason. That is helpful. Basically clock-wise rotations about -z axis of blade coordinate system (Fig 9, pg 10 FAST manual) are positive (for both pitch and twist). For an up-wind turbine such a rotation causes leading edge more into upwind.
by KumaraRaja.Eedara
Fri Jul 12, 2019 3:00 pm
Forum: Controls
Topic: questions about reference control input
Replies: 61
Views: 19457

Re: questions about reference control input

Dear Jason, One more question, rather would like to confirm my understanding. In the input file to FAST (AeroDynV14), for each blade, the 'AeroTwst' align with chord,structural twist etc,is specified at different blade sections. And I observed that 'AeroTwst' value decreases from root section to tip...

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