Trasition from Aerodyn_driver BASIC format to Aerodyn_driver ADVANCED format

[Laurens09]

Good morning, I have done a simulation by using AeroDyn Driver BASIC format, which have allowed to get the expected results. Than I have tried to repeat it with the ADVACED format (same AERODYN.dat file), but the results have been different. I think that there are no mistakes in the input file: I have controlled the geometrical parameters many times.

Do you have any idea about how to solve the problem? Are there any bugs or specific procedure for the advanced format?

Thank you

[jjonkman]

Dear @Laurens09,

I'm not aware of any issues with the "advanced format" of the standalone AeroDyn driver. It has hard to guess what the problem could be without seeing your "basic" and "advanced" driver input files.

Best regards,

[jjonkman]

Dear @Laurens09,

Can you clarify why you have a nonzero base origin and are not locating the nacelle origin directly above the tower origin in the advance format (I would only expect an offset in Z)? (It looks like your tower is slanted.)

I also see that the hub location is not the same tower height and hub location are not the same between the "basic" and "advanced" models.

Best regards,

[Laurens09]

Dear @jjonkman,

you are right. There should be a 0.45 offset in Z direction for BaseOriginInit(1) of Basic format.
Moreover there is a mistake for ShftTilt, it should be 0°.

With these two corrections, the tower height and hub location should be the same (are you agree with that?), and the results are substantially the same of before. I think that there should be some other mistakes in the Advanced format because the results of the basic model are correct. Do you have any other observations?

Yes the tower is slanted. Let see the image below.

Best regards

[jjonkman]

Dear @Laurens09,

Can you clarify what you've changed in your basic and advanced input files or reshare the updated files?

Best regards,

[Laurens09]

Dear @jjonkman,

I have changed the ShftTilt and BaseOriginInit of the basic format. The advanced format is the same as before.

You can see below the updated basic format.

Best regards

### BASIC FORMAT

----- AeroDyn Driver Input File ---------------------------------------------------------
BAR turbine driver input file, using advanced input, sinusoidal base motion
----- Input Configuration ---------------------------------------------------------------
False           Echo         - Echo input parameters to "<rootname>.ech"?
        0       MHK          - MHK turbine type (switch) {0: not an MHK turbine, 1: fixed MHK turbine, 2: floating MHK turbine}
        1       AnalysisType - {1: multiple turbines, one simulation, 2: one turbine, one time-dependent simulation, 3: one turbine, combined cases}
        7.      TMax         - Total run time [used only when AnalysisType/=3] (s)
        0.1     DT           - Simulation time step [used only when AnalysisType/=3] (s)
"./AERODYN.dat" AeroFile     - Name of the primary AeroDyn input file
----- Environmental Conditions ----------------------------------------------------------
     1.177     FldDens      - Density of working fluid (kg/m^3)
   1.45e-5     KinVisc      - Kinematic viscosity of working fluid (m^2/s)
       335     SpdSound     - Speed of sound in working fluid (m/s)
    103500     Patm         - Atmospheric pressure (Pa) [used only for an MHK turbine cavitation check]
      1700     Pvap         - Vapour pressure of working fluid (Pa) [used only for an MHK turbine cavitation check]
         0     WtrDpth      - Water depth (m)
----- Inflow Data -----------------------------------------------------------------------
          0      CompInflow  - Compute inflow wind velocities (switch) {0=Steady Wind; 1=InflowWind}
"./InflowWind"   InflowFile  - Name of the InflowWind input file [used only when CompInflow=1]
       4.19      HWindSpeed  - Horizontal wind speed   [used only when CompInflow=0 and AnalysisType=1] (m/s)
        1.2      RefHt       - Reference height for horizontal wind speed [used only when CompInflow=0]     (m)
          0      PLExp       - Power law exponent   [used only when CompInflow=0 and AnalysisType=1]                           (-)
----- Turbine Data ----------------------------------------------------------------------
1               NumTurbines - Number of turbines
----- Turbine(1) ------------------------------------------------------------------------
True            BasicHAWTFormat(1)     - Flag to switch between basic or generic input format {True: next 7 lines are basic inputs, False: Base/Twr/Nac/Hub/Bld geometry and motion must follow}
 0,0,0.45    BaseOriginInit(1) - Coordinates of turbine base in global coordinates (m)
          3            NumBlades(1)    - Number of blades (-)
          0.089000     HubRad(1)       - Hub radius (m)
          2.086        HubHt(1)        - Hub height (m)
         -0.094670     Overhang(1)     - Overhang (m)
          0            ShftTilt(1)     - Shaft tilt (deg)
          0            Precone(1)      - Blade precone (deg)
          0.036670     Twr2Shft(1)     - Vertical distance from the tower-top to the rotor shaft (m)
----- Turbine(1) Motion [used only when AnalysisType=1] ---------------------------------
0         BaseMotionType(1)      - Type of motion prescribed for this base {0: fixed, 1: Sinusoidal motion, 2: arbitrary motion} (flag)
1         DegreeOfFreedom(1)     - {1:xg, 2:yg, 3:zg, 4:theta_xg, 5:theta_yg, 6:theta_zg} [used only when BaseMotionType=1] (flag)
5.0       Amplitude(1)           - Amplitude of sinusoidal motion  [used only when BaseMotionType=1] (m or rad)
0.1       Frequency(1)           - Frequency of sinusoidal motion  [used only when BaseMotionType=1] (Hz)
"unused"  BaseMotionFileName(1)  - Filename containing arbitrary base motion (19 columns: Time, x, y, z, theta_x, ..., alpha_z)  [used only when BaseMotionType=2]
0         NacYaw(1)              - Yaw angle (about z_t) of the nacelle (deg)
240       RotSpeed(1)            - Rotational speed of rotor in rotor coordinates (rpm)
0         BldPitch(1)            - Blades pitch (deg)

[jjonkman]

Dear @Laurens09,

I don't agree that the basic and advanced models have the same tower-top and hub locations. In the basic format, it appears that you've placed the hub at (-0.9467, 0, 2.086) m relative to the base origin, and in the advanced format, it appears that you've placed the hub at (-0.23106, 0, 1.647338) m relative to the base origin.

Best regards