Search found 29 matches

by Daniel.Wu
Sun Jun 18, 2017 9:54 am
Forum: Rotor Aerodynamics
Topic: Effects of the time step on AoA for FAST v8.16
Replies: 1
Views: 3775

Effects of the time step on AoA for FAST v8.16

Hi All, I ran two cases of FAST simulations on NREL 5MW at the rated configuration ( -5 tilt, -2.5 pre-cone, etc.). The wind condition is nonuniform wind with the power-law profile, 10 m/s at 100 m. All the DoFs in the ElastoDyn are disabled so that the rotor constantly rotate at 12 rpm. The BeamDyn...
by Daniel.Wu
Fri Mar 31, 2017 11:18 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST v8 & Standalone AeroDyn v15.03 convergence problems for high shear-exp wind profile
Replies: 5
Views: 1514

Re: FAST v8 & Standalone AeroDyn v15.03 convergence problems for high shear-exp wind profile

Hi Jason, Thank you for the information. I will try to recompile FAST to solve the AeroDyn issue, but I am not very good at this. I also found that the convergence issue can be solved by setting TanInd to false. However, this may not fully capture aerodynamics of the rotor. I am not sure if this is ...
by Daniel.Wu
Thu Mar 30, 2017 11:14 am
Forum: Computer-Aided Engineering Software Tools
Topic: FAST v8 & Standalone AeroDyn v15.03 convergence problems for high shear-exp wind profile
Replies: 5
Views: 1514

Re: FAST v8 & Standalone AeroDyn v15.03 convergence problems for high shear-exp wind profile

Hi Jason, Thank you for your suggestion. I changed the ElastoDyn DoF setting and disable all the DoFs (since my focus is on the aerodynamics). However, the convergence problem still exists for the straight NREL5MW blade FAST simulation. is this caused by setting SkewMod=1? I am not sure why changing...
by Daniel.Wu
Thu Mar 30, 2017 11:04 am
Forum: Computer-Aided Engineering Software Tools
Topic: Question on AeroDyn nodal relative wind speed, Vrel
Replies: 1
Views: 621

Question on AeroDyn nodal relative wind speed, Vrel

Hi All, I am running NREL 5MW cases with different setting in its AeroDyn primary file. My desired output are the AoA, Cl, Cd, and Vrel (relative wind speed) at all 9 nodes of the blade. The wind condition is power-law wind profile at 10 m/s (at the hub height) and 0.14 power-exp. In the AeroDyn pri...
by Daniel.Wu
Mon Mar 13, 2017 12:36 pm
Forum: Computer-Aided Engineering Software Tools
Topic: FAST v8 & Standalone AeroDyn v15.03 convergence problems for high shear-exp wind profile
Replies: 5
Views: 1514

FAST v8 & Standalone AeroDyn v15.03 convergence problems for high shear-exp wind profile

Hello All, I am running Test26.fst with slight modification as the following 1. Disable ServoDyn and GenDOF set to be false 2. Steady Wind Conditions with speed 10 mps at 90 m. The PLexp is 0.35. 3. The AeroDyn Blade file has ZERO curvature ( BlCrvAC ), sweep ( BlSwpAC ), and curvature angle ( BlCrv...
by Daniel.Wu
Thu Mar 09, 2017 9:41 am
Forum: Computer-Aided Engineering Software Tools
Topic: BeamDyn: Convert Wiener-Milenkovic to rotation matrix
Replies: 7
Views: 1799

Re: BeamDyn: Convert Wiener-Milenkovic to rotation matrix

Hi Jason, Just want to follow up on this topic. Since there are errors in converting rotational/angular deflections in BeamDyn, does it mean that the angle of attack (AoA) from AeroDyn has errors as well? BeamDyn and AeroDyn are coupled via FAST, so if the angular deformations from BeamDyn are wrong...
by Daniel.Wu
Thu Jan 19, 2017 2:34 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Questions on FE Nodes v.s. Blade Nodes
Replies: 13
Views: 3205

Re: Questions on FE Nodes v.s. Blade Nodes

Hi Jason, Please help me clarify on key points and FE nodes. If I model a blade with one element with order_elemt =6 and 49 key points, there are 7 FE nodes. I understand each key point has the sectional properties of the blade (6X6 stiffness and mass matrices), but since number of key points are si...
by Daniel.Wu
Fri Jan 06, 2017 1:37 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Azimuth Angle of the Blade
Replies: 11
Views: 34956

Re: Azimuth Angle of the Blade

Dear Jason, I just want to follow up on the azimuth from ElastoDyn. LSSTipPxa is the output name of the rotor azimuth angle position, as well as the azimuth of blade 1. According to your FAST v6 equations of motion, LSSTipPxa is defined as (in the FASTMotions file) http://i.imgur.com/BI2DAtn.jpg q_D...
by Daniel.Wu
Wed Dec 07, 2016 6:50 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Questions on FE Nodes v.s. Blade Nodes
Replies: 13
Views: 3205

Re: Questions on FE Nodes v.s. Blade Nodes

Hi Jason, I have some question about the BeamDyn "member" versus LSFEs elements. Please help me out. From what I read from BeamDyn manual, it seems like a "member" that defined by at least 3 key points forms a LSFE element. All the nodes then are locate at GLL quadrature points. ...
by Daniel.Wu
Tue Nov 29, 2016 1:12 pm
Forum: Computer-Aided Engineering Software Tools
Topic: FAST theory manual
Replies: 303
Views: 45483

Re: FAST theory manual

Dear Dr. Jonkman,

Can you also send me the "Unofficial FAST Theory Manual" for FAST v8 as well?

I also wondering is there any unofficial ElastoDyn manual or FAST v7 manual is basically the same as ElastoDyn?


My mail address: danielw5@vt.edu

Thank you
by Daniel.Wu
Thu Oct 27, 2016 12:07 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Creating BeamDyn Blade Input
Replies: 19
Views: 3551

Re: Creating BeamDyn Blade Input

Dear Dr. Jonkman, Thank you so much for your input. Now, I am able to re-construct NREL 5MW BeamDyn blade input file based on Table 2-1 from the paper you post. However, I have some questions on the stiffness and mass matrices in the NREL 5MW eaxmple. For Stiffness matrices, K_ShrFlp = K_ShrEdg = EA...
by Daniel.Wu
Wed Oct 26, 2016 1:00 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Creating BeamDyn Blade Input
Replies: 19
Views: 3551

Re: Creating BeamDyn Blade Input

Dear Dr. Jonkman, I am trying to use NuMAD/BPE to create Sandia SNL100 series blade for BeamDyn inputs. However, the NuMAD/BPE stop working after the ANSYS FEA. I have double checked that I followed the manual exactly and all the configurations are correct. I could not resolve this issue. I emailed ...
by Daniel.Wu
Thu Oct 13, 2016 12:55 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Issues with AeroDyn Standalone
Replies: 3
Views: 709

Re: Issues with AeroDyn Standalone

Dear Jason, Thank you so much for the explanation. Just few questions: 1. How to know the z_disk points to right or left? 2. Based on your explanation, Case 2: Blade 1 with azimuth angle at -90 deg will point upward. Case 3: Blade 1 with azimuth angle at 90 deg will point upward as well. Please see ...
by Daniel.Wu
Thu Oct 13, 2016 11:13 am
Forum: Computer-Aided Engineering Software Tools
Topic: Issues with AeroDyn Standalone
Replies: 3
Views: 709

Issues with AeroDyn Standalone

Hi All, I am currently testing the AeroDyn v15 Standalone version. I found something interesting with the results. Any help is greatly appreciated. I did a series of tests on NREL 5MW blade with 10 rpm initial rotor speed and 10 mps steady uniform wind (zero precone, zero shearExp, zero yaw, and zer...
by Daniel.Wu
Thu Sep 29, 2016 1:55 pm
Forum: Computer-Aided Engineering Software Tools
Topic: Azimuth Angle of the Blade
Replies: 11
Views: 34956

Re: Azimuth Angle of the Blade

Dear Jason, Thank you so much for the explanation. Please allow me to recap and summarize what you mentioned to see if I really understand it. Please correct me if I am wrong. 1. ElasoDyn's Blade 1 initial azimuth angle has nothing to do with AeroDyn v15 azimuth angle. So that even if I change the E...

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