How to import hub motions to AeroDyn?

Wind & Water Computer-Aided Engineering Software Tools
1

I am investigating the relation of aerodynamic loads at hub with the hub motions by using AeroDyn V15 (April 2016). At the first stage, I plan to import time-histories of displacements (pre-simulated) to be hub translations/rotations via driver file/AeroDyn code. It seems clear that I can transfer Z-displacement to HubHt and Z-rotation to Yaw at every time step (instead of inputting them in AeroDyn driver file).

My questions are:

  1. What is the parameter in AeroDyn driver file or array in AeroDyn code that is compatible to the real-time pitch angle (i.e. X-rotation) of the hub?
  2. Also, what are the parameters in AeroDyn driver file or arrays in AeroDyn code those are compatible to X-displacement, Y-displacement and Y-rotation of the hub?
  3. Is it possible to import real-time velocities and accelerations of the hub to AeroDyn?

Thanks a lot.
Nguyen

2

Dear Nguyen,

Unless you change the driver input file for the standalone AeroDyn v15 module, the driver input file is set up for running simple cases involving a rigid wind turbine subject to fixed wind, rotor speed, blade-pitch, and nacelle-yaw. It sounds like you want to prescribe more general 6-DOF motion of the hub, which you’ll be able to achieve by modifying the driver. AeroDyn v15 is a module following the requirements of the FAST modular framework, as such, most of the inputs to AeroDyn from the driver reside on mesh data structures. You’ll need to set the following inputs (arrays) to AeroDyn every time step:

  • TowerMotion%TranslationDisp(3,NumTwrNds) - Translational displacements of each node along the tower.
  • TowerMotion%Orientation(3,3,NumTwrNds) - Orientations (3x3 direction-cosine matrix) of each node along the tower.
  • TowerMotion%TranslationVel(3,NumTwrNds) - Translational velocities of each node along the tower.
  • HubMotion%TranslationDisp(3,1) - Translational displacement of the hub center.
  • HubMotion%Orientation(3,3,1) - Orientation (3x3 direction-cosine matrix) of the hub.
  • HubMotion%RotationVel(3,1) - Rotational velocity of the hub.
  • BladeRootMotion(NumBlades)%Orientation(3,3,1) - Orientations (3x3 direction-cosine matrix) of each blade at the root.
  • BladeMotion(NumBlades)%TranslationDisp(3,NumBlNds) - Translational displacements of each node along each blade.
  • BladeMotion(NumBlades)%Orientation(3,3,NumBlNds) - Orientations (3x3 direction-cosine matrix) of each node along each blade.
  • BladeMotion(NumBlades)%TranslationVel(3,NumBlNds) - Translational velocities of each node along each blade.
  • InflowOnBlade(3,NumBlNds,NumBlades) - Undisturbed wind-inflow velocities at each node along each blade.
  • InflowOnTower(3,NumTwrNds) - Undisturbed wind-inflow velocities at each node along the tower.

Hopefully by studying the existing AeroDyn driver code it will be clear what you need to change.

Best regards,

3

Thank you Jason for helpful advises. You are right, I plan to prescribe more general 6-DOF motions of the hub in order to investigate the relations of those motions with aerodynamic loads. I am now studying AeroDyn driver code.