1. Design Tools & Codes Technology Viability Jason Jonkman, Ph.D.
NREL/NWTC
March 11, 2010

2. Modeling Requirements
Coupled aero-hydro-servo-elastic interaction
Wind-inflow
Discrete events
Turbulence
Waves
Regular
Irregular
Aerodynamics
Induction
Rotational augmentation
Skewed wake
Dynamic stall
Hydrodynamics
Diffraction
Radiation
Hydrostatics
Structural dynamics
Gravity / inertia
Elasticity
Foundations / moorings
Control system
Yaw, torque, pitch

3. What are Design Tools & Codes?
Codes developed for direct application in the design process
Preprocessors, simulators, & post-processors
Primary (simulation) codes are
Multi-physics models (aero-hydro-servo-elastic)
Full-system models (foundation + substructure + tower + nacelle + drivetrain + rotor)
Developed uniquely to the wind application (not general purpose)
Codes developed to run on standard PCs (not supercomputers)
Code accuracy is only as good as the input
Input must be tuned with test data to ensure accurate output

4. Statement of the Problem
Design codes are fundamental to the design of wind turbines
Program-developed codes are the industry standard
Improvements are key for developing better technology
Larger sizes
Unique architectures
Novel control devices
Offshore support structures
Innovation is essential for COE reductions & reliability improvements
Robust analysis capability is required to develop innovative technology
Enhanced analysis capability, accuracy, & speed are essential for achieving DOE goals of reduced COE & improved reliability

5. Technical Approach Current Emphasis
Develop & disseminate enhanced codes
Base priorities on user feedback & strategic initiatives
Collaborate under Risø-DTU MOU & CENER CRADA
Provide technical support to the wind industry
Current Emphasis

6. Schedule & Budget
The project is ongoing with no planned completion date
Milestones for FY2010
3/31/2010: Release updated version of WT_Perf
3/31/2010: Release updated versions of AeroDyn, FAST, & A2AD with improved interface
4/30/2010: Publish and present paper on BModes at 2010 AIAA SDM conference
Note: In FY2009, the reported budget includes funding for both the “Design Tools & Codes” & “Systems Analysis” subtasks; the “Systems Analysis” subtask started & ended in FY2008 with J. Jonkman as the PI & was used to support a portion of the GRC analysis not normally supported under the “Design Tools & Codes” subtask
Note: In FY2010, the reported budget includes funding for both the “Design Tools and Codes” and “AeroDyn Development” subtasks; the “AeroDyn Development subtask is new to FY2010 with G. Bir as the PI
Budget History
FY2008
FY2009
FY2010
DOE
Cost-share
$750K $0
$835K
$850K
Key Staff

7. Accomplishments / Progress – WT_Perf
WT_Perf Overview
Calculates steady-state rotor performance
Inputs are rotor geometry, airfoil data, wind, pitch, & rotor speed
Uses BEM theory
Recent Accomplishments
Added rotor performance optimization algorithm (Harp_Opt)
Current Activities
Improve solution algorithm
Introduce cavitation onset check
K. Johnson, NREL
Power Coefficient for the CART2

8. Accomplishments / Progress – AeroDyn
AeroDyn Overview
Computes aerodynamics (lift, drag, pitch) as part of the aero-elastic solution
Wind-inflow input
Uniform, unsteady
Turbulent (TurbSim)
Wake modeling
BEM (quasi-steady)
GDW (dynamic)
Dynamic stall modeling
Beddoes-Leishman (semi-empirical)
Recent Accomplishments
Initiated overhaul to improve interfaces, functionality, & usability
Hosted kick-off meeting with 50 attendees
Current Activities
Improve interface to structural modules
Rework theory basis
Burton, et al (2001)
BEM Discretization

9. Accomplishments / Progress – HydroDyn
HydroDyn Overview
Computes wave-kinematics & hydrodynamics as part of the hydro-elastic solution
Waves & currents
Regular or irregular linear waves
Steady sub-surface, near-surface, & depth-independent currents
Hydrodynamics
Morison’s equation for monopiles
Linear radiation/diffraction theory for floating platforms
Moorings
Quasi-static (nonlinear catenary equations)
Recent Accomplishments
Published Wind Energy article summarizing development & verification
Current Activities
Add 2nd-order irregular waves for monopiles (with UT-Austin)
Improve interface to structural modules
Publish users guide
Floating Wind Turbine Concepts

10. Accomplishments / Progress – FAST
FAST Overview
Computes structural & control-system responses as part of the aero-hydro-servo-elastic solution
Combined modal & MBS formulation through 24 DOFs
Controls through subroutines, DLLs, or Simulink®
Nonlinear time-domain solution for loads analysis
Linearization for controls & stability analysis
Preprocessor for building turbine models in MSC.ADAMS
Current Activities
Add two mass dampers DOFs (with UMass)
Add earthquake excitation module (with UC-San Diego)
Include more built-in control options
Include new output functionality
Improve FAST-to-ADAMS generation of curved & swept blades
DOFs for a 3-Bladed Turbine

11. Accomplishments / Progress – A2AD
A2AD & MSC.ADAMS Overview
Commercial product from MSC Software
Computes structural & control-system responses as part of the aero-hydro-servo-elastic solution
MBS formulation with unlimited DOFs
Controls through subroutines or DLLs
Nonlinear time-domain solution
Linearization of nonrotating system
Datasets can be created by FAST
Bypasses some limitations of FAST
Current Activities
Same as for FAST, plus
Restructure A2AD for improved numerical processing
Model Created by FAST

12. Accomplishments / Progress – BModes
BModes Overview
Computes modal dynamics of blades & towers
Inputs are the boundary conditions & distributed isotropic beam properties
Considers axial-flap-lag-torsion coupling
Uses a 15-DOF FE specially developed to handle rotation-related terms
Recent Accomplishments
Added modeling of flexible foundations, monopiles, & floating platforms
Published paper on modal dynamics at 2008 OMAE conference
Current Activities
Add gravitational effects for towers
Publish verification results at 2010 AIAA SDM conference
Mode Shapes of Land-Based
NREL 5-MW Tower

13. Accomplishments / Progress – MCrunch
MCrunch Overview
A MATLAB®-based postprocessor for data analysis
Merges features from legacy codes (Crunch, GPP, GenStats, & Fatigue)
Scales, offsets, & calculated channels
Statistics
Probability density functions
Power spectral density
Plotting
Recent Accomplishments
First released in FY2008
Current Activities
Modularize for improved efficiency
Add rainflow counting, DELs, & lifetime damage for fatigue analysis
Add extreme event tables for ultimate analysis
Example Outputs from MCrunch

14. Accomplishments / Progress – Support
Technical Support Overview
Support offered through
Supplying of updated codes, including source
Publishing user’s guides
Online Q&A forum
Phone &
Solicitation of user requirements
Workshops
Recent Accomplishments
Hosted workshop with 47 attendees
NWTC Design Codes Website
NWTC Design Codes Forum

15. Accomplishments / Progress – Collaborations
CENER CRADA
Established in FY2007 for shared code development & testing
Cooperation in IEA Task 23 OC3
Collaboration with AeroDyn overhaul, FAST upgrades, MCrunch testing, & floating system analysis
Risø-DTU MOU
Collaboration currently limited to cooperation within OC3 & UpWind
To further collaboration, 2 NREL staff will spend 3 months at Risø-DTU beginning April 2010
Topics of discussion
Shared code development
Modularization & co-simulation of codes
Offshore wind turbine conceptual design & analysis
Site-specific inflow characterization
Establishment of a CRADA

16. Proposed Next Steps Project’s biggest challenge Future opportunities
User demand for improvements greatly exceeds current staff resources
Future opportunities
Implement coupled flap-lag-torsion modes in FAST
Add FAST animation functionality
Allow anisotropic materials & blade curve & sweep in BModes & FAST
Merge rigid- & flexible-bodies within MBS models
Support detailed gearbox modeling
Introduce higher fidelity aerodynamic models
e.g., vortex wake models
Improve modeling of offshore floating turbines
Introduce modeling of offshore fixed-bottom space frames (tripods, jackets)
Introduce modeling of smart blades
e.g., deformable trailing edge
Modularization & co-simulation of codes
G. Bir, NREL