AeroDyn output file

Wind & Water Computer-Aided Engineering Software Tools
1

I am trying to collect some aerodynamic outputs to plot. I am running the 5MW wind turbine NREL model in FAST with AeroDyn. In reading the AeroDyn manual, the description of the output (.opt) file is completely different from what I’m getting. The manual describes a file with a header and then columns of data corresponding to those in Table 10.1. I have selected USE_CM. Here is what my .opt file looks like after running the simulation:

This file was generated by AeroDyn (v13.00.00a-bjj, 31-Mar-2010) on 08-Apr-2011 at 11:01:52.

Inputs read in from the AeroDyn input file:
NREL 5.0 MW offshore baseline aerodynamic input properties; Compatible with AeroDyn v12.58.

SI Units for input and output
BEDDOES Dynamic stall model [Beddoes]
USE_CM Aerodynamic pitching moment model [Pitching Moments calculated]
EQUIL Inflow model [Equilibrium]
SWIRL Induction factor model [Normal and Radial flow induction factors calculated]
5.00000E-03 Convergence tolerance for induction factor
PRAND Tip-loss model [Prandtl model]
PRAND Hub-loss model [Prandtl model]
“12mps.wnd” Wind file name
90 Wind reference (hub) height, m
0 Tower shadow centerline velocity deficit
9999.9 Tower shadow half width, m
9999.9 Tower shadow reference point, m
1.225 Air density, kg/m^3
1.46400E-05 Kinematic air viscosity, m^2/sec
2.47900E-02 Time interval for aerodynamic calculations, sec
8 Number of airfoil files used. Files listed below:
“AeroData\Cylinder1.dat”
“AeroData\Cylinder2.dat”
“AeroData\DU40_A17.dat”
“AeroData\DU35_A17.dat”
“AeroData\DU30_A17.dat”
“AeroData\DU25_A17.dat”
“AeroData\DU21_A17.dat”
“AeroData\NACA64_A17.dat”
17 Number of blade elements per blade

 Element     RELM       Twist       DR        Chord      NFoil     Print?    Tip-loss   Hub-loss
   (-)        (m)       (deg)       (m)        (m)        (-)     (Yes/No)   constant   constant

        1    2.86670   13.30800    2.73330    3.54200          1         No   31.46474    1.36670
        2    5.60000   13.30800    2.73330    3.85400          1         No   15.37500    4.10000
        3    8.33330   13.30800    2.73330    4.16700          2         No    9.84005    6.83330
        4   11.75000   13.30800    4.10000    4.55700          3         No    6.54255   10.25000
        5   15.85000   11.48000    4.10000    4.65200          4         No    4.46215   14.35000
        6   19.95000   10.16200    4.10000    4.45800          4         No    3.23684   18.45000
        7   24.05000    9.01100    4.10000    4.24900          5         No    2.42931   22.55000
        8   28.15000    7.79500    4.10000    4.00700          6         No    1.85702   26.65000
        9   32.25000    6.54400    4.10000    3.74800          6         No    1.43023   30.75000
       10   36.35000    5.36100    4.10000    3.50200          7         No    1.09973   34.85000
       11   40.45000    4.18800    4.10000    3.25600          7         No    0.83622   38.95000
       12   44.55000    3.12500    4.10000    3.01000          8         No    0.62121   43.05000
       13   48.65000    2.31900    4.10000    2.76400          8         No    0.44245   47.15000
       14   52.75000    1.52600    4.10000    2.51800          8         No    0.29147   51.25000
       15   56.16670    0.86300    2.73330    2.31300          8         No    0.18249   54.66670
       16   58.90000    0.37000    2.73330    2.08600          8         No    0.10441   57.40000
       17   61.63330    0.10600    2.73330    1.41900          8         No    0.03326   60.13330

Rotor radius = 62.940 m
Hub radius = 1.499 m
Number of blades = 3

BEDDOES DYNAMIC STALL PARAMETERS:

CN SLOPE 0.0000 0.0000 7.4888 7.1838 7.3326 6.4462 6.2047 6.0031
STALL CN (UPPER) 0.0000 0.0000 1.3519 1.6717 1.4490 1.4336 1.4144 1.4073
STALL CN (LOWER) 0.0000 0.0000 -0.3226 -0.3075 -0.6138 -0.6873 -0.5324 -0.7945
ZERO LIFT AOA 0.0000 0.0000 -1.3430 -1.8330 -2.3220 -4.2422 -5.0609 -4.4320
MIN DRAG AOA 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 -1.5000 -1.0000
MIN DRAG COEFF 0.5000 0.3500 0.0113 0.0094 0.0087 0.0065 0.0057 0.0052

 VORTEX TRANSIT TIME FROM LE TO TE    11.00000    
 PRESSURE TIME CONSTANT               1.700000    
 VORTEX TIME CONSTANT                 6.000000    
 F-PARAMETER TIME CONSTANT            3.000000

Am I doing something wrong?

2

Chris,

Are you really wanting the Blade-Element data? It’s a time series of aerodynamic parameters for specified blade stations. It includes stuff such as alpha, Cl, Cd, and wind speed.

The .opt file is simply a regurgitation of the input files.

Marshall

3

Marshall,

I actually figured out what I was doing wrong. I had the NOPRINT command in all of the elements in the input file (I hadn’t changed this after I downloaded it from the site). I changed that and then had to figure out where the outputs were written. The AeroDyn doesn’t explain that the output file has the .elm extension. I found that, though, so I think I’m good to go. The weird thing is that Windows thinks the .elm extension signifies a theme file.

4

Chris,

I guess we’ll need to be more specific about the name of the element file when we release the new AeroDyn.

I’m also using 4-letter extensions for my programs now because of conflicting extension names. Maybe the next AeroDyn will make it a elem file.

Marshall