# Presentation: 794294

## AeroDyn Interface with Structural Codes —  

- 	AeroDyn Overhaul Kick-Off Meeting
- National Wind Technology Center (NWTC)
- Boulder, CO (USA)
- February 13-14, 2008

**AeroDyn Interface with Structural Codes —  **
**Summary of Structural-Dynamic Codes**
**that Interface with AeroDyn**

## Coupled Aero-Hydro-Servo-Elastics

## Structural-Dynamic Codes that Interface to AeroDyn

- YawDyn
- SymDyn
- FAST
- MSC.ADAMS®
- MBDyn (interface under development)
- SIMPACK® (separate presentation)

## YawDyn

- Simple structural simulator written by the University of Utah
- AeroDyn started out as a tightly integrated part of YawDyn
- YawDyn is easy to use, with 2 or 4 optional DOFs:
- Yaw DOF
- Teeter (2-bladed) or blade flap (3-bladed) DOFs
- Constant speed
- Only control ability is to interpolate multiple airfoil tables for partial-span pitch (within AeroDyn)
- Proposing to drop support for YawDyn and replace it with a “FAST Lite”:
- It is not worth the effort to link YawDyn with the new AeroDyn
- What features should be available in a “FAST Lite”?

## SymDyn

- Developed by K. Stol (now of the University of Auckland) and G. Bir
- Dynamics as a system of rigid bodies connected by joints and discrete spring-dampers; allows up to 10 DOFs:
- Individual blade flapping
- Tower fore-aft, side-to-side, and torsion
- Rotor teeter
- Generator rotation and drivetrain torsion
- Nacelle yaw and pitch
- Integrated within Simulink®  with MATLAB®
- Nonlinear time-domain analysis with controls
- Linearization procedure for state-space-based controls design and stability analysis:
- Stability analysis through Floquet theory
- No longer supported:
- Most functionality added to FAST

## FASTAt a Glance

- FASTAt a Glance

**F**atigue, **A**erodynamics, **S**tructures, and **T**urbulence
- Developed by NREL/NWTC:
- Originated from developments at Oregon State University
- Freely distributed with source code
- Combined modal and multibody representation:
- Modal — blades and tower
- Rigid — support platform, nacelle, generator, hub, and tail
- Controls implementation through user-developed Fortran subroutines, Bladed-style DLL, or Simulink®  with MATLAB®
- Nonlinear time-domain analysis with controls
- Linearization procedure for state-space-based controls design and stability analysis
- Preprocessor for MSC.ADAMS

## FASTTurbine Configurations Available

- 2- or 3-bladed HAWT
- Upwind or downwind rotor
- Rigid or teetering hub
- Rotor- and/or tail-furling
- Land-based or offshore
- Offshore monopiles or floating

## FASTDegrees of Freedom

- 24 DOFs available for 3-bladed turbine; 22 DOFs available for 2-bladed turbine:
- Blade flexibility — 2 flap and 1 edge mode DOF per blade
- Tower flexibility — 2 fore-aft and 2 side-to-side mode DOFs
- Drivetrain — 	 1 variable generator speed DOF and         				 1 shaft torsion DOF
- Nacelle yaw — 	 1 yaw hinge DOF
- Rotor teeter — 	 1 rotor teeter hinge DOF with optional 3 			 (for 2-bladed rotor only)
- Rotor-furl — 	 1 furl hinge DOF of *arbitrary orientation **	**	**	**	** and location *between the nacelle & rotor
- Tail-furl — 	 1 furl hinge DOF of *arbitrary orientation **	**	**	**	** and location *between the nacelle & tail
- Platform — 	 3 translation (surge, sway, and heave) and *	**	**	** *3 rotation (roll, pitch, and yaw) DOFs

## MSC.ADAMS®At a Glance

**A**utomatic **D**ynamic **A**nalysis of **M**echanical **S**ystems
- Commercial product from MSC Software
- General purpose for any mechanical system
- Multibody dynamics representation
- Virtually unlimited structural DOFs
- Controls implementation through user-developed Fortran subroutines or Bladed-style DLL
- Nonlinear time-domain analysis with controls
- Linearization of nonrotating system for modal analysis
- Datasets can be created by FAST
- Interface to AeroDyn through A2AD software

## MSC.ADAMS®Limitations in FAST that are Bypassed

- Torsion and extensional DOFs in the blades and tower
- Mass and elastic offsets in the blades and tower
- Higher order modes
- Dynamics of pitching blades
- Graphical output capabilities
- Unconventional configurations:
- Flap hinges
- Flap/twist coupling in blades
- Precurved or preswept blades
- Bendable shaft
- Tower guy wires

*ADAMS Model Generated by FAST*

## MBDyn

**M**ulti**B**ody **Dyn**amics representation
- Developed at the Dipartimento di Ingegneria Aerospaziale of the University “Politecnico di Milano”, Italy
- Freely distributed with source code
- General purpose for any mechanical system
- Virtually unlimited structural DOFs
- Controls implementation through user-developed subroutines
- AeroDyn interface under development by Patrick Rix of REpower