Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2014-1418P An Update on the Sandia 100-meter Blade Project: Large Blade Public Domain Reference Models and Cost Models D. Todd Griffith ([email protected]) Sandia National Laboratories Sandia Wind Turbine Blade Workshop (8/27/2014)
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2014-1418P
An Update on the Sandia 100-meter Blade Project: Large Blade Public Domain Reference Models and Cost Models
Blade design studies required a turbine model for aero-elastic loads analysis: we up-scaled the NREL 5MW turbine model and also released that model as a 13.2 MW reference with the blade files
2009: Project start, scaling studies, parameters for the baseline 100-meter blade
2011: Completed and published the SNL100-00 All-glass Baseline Blade
The inboard airfoils of maximum chord were produced by interpolation. Otherwise, this baseline SNL100-00 designed uses a scaled-up chord distribution and
outboard airfoil shapes from DOWEC; same twist as well
[2]
0.0 0.2 0.4 0.6 0.8 1.0
-4
-3
-2
-1
0
1
2
3
4
5
6 Leading Edge
Trailing Edge
Blade Span Fraction
(met
ers)
3-Blade Upwind Rotor
Parameter ValueBlade Designation SNL100-00
Wind Speed Class IB
Blade Length (m) 100
Blade Weight (kg) 114,172
Span-wise CG location (m) 33.6
# shear webs 3
Maximum chord (m) 7.628 (19.5% span)
Lowest fixed root natural frequency (Hz)
0.42
ControlVariable speed, collective pitch
Notes6% (weight) parasitic
resin, all-glass materials
Material Description Mass (kg)Percent
Blade Mass
E-LT-5500Uni-axial
Fiberglass37,647 32.5%
SaertexDouble Bias Fiberglass
10,045 8.7%
EP-3 Resin 51,718 44.7%
Foam Foam 15,333 13.3%
Gelcoat Coating 920 0.8%
Max operating speed: 7.44 RPMCut in/out wind speed: 3.0/25.0 m/s
Design Scorecards for all Designs
Industry survey of blade mass: Commercial blades (20-60 meters), recent large prototype blades (73-83 meters), and research concept blades (61.5, 86, 100, 123 meters)
SNL100-XXSeries
SNL100-XX series shows a pathway to high innovation weight
SNL100-00: Glass
Baseline
SNL100-01:Carbon spar
SNL100-02:
Core SNL100-03: Geometry
SNL100 Follow-on Projects
1. Sandia Flutter Study2. Altair/Sandia CFD Study3. Sandia Blade Manufacturing Cost Model4. 100m Carbon Design Studies: SNL100-015. 100m Core Material Studies: SNL100-026. 100m Aero-structural Studies: SNL100-03
These are the follow-on study areas addressed by Sandia; many
additional issues addressed by users of the 100-meter blade
reference models.
12
1. Flutter parameters study and improvements to flutter tool
1. Resor, Owens, and Griffith. “Aeroelastic Instability of Very Large Wind Turbine Blades.” Scientific Poster Paper; EWEA Annual Event, Copenhagen, Denmark, April 2012.
2. Owens, B.C., Griffith, D.T., Resor, B.R., and Hurtado, J.E., “Impact of Modeling Approach on Flutter Predictions for Very Large Wind Turbine Blade Designs,” Proceedings of the American Helicopter Society (AHS) 69th Annual Forum, May 21-23, 2013, Phoenix, AZ, USA, Paper No. 386.
3. Sandia Blade Manufacturing Cost Model (version 1.0)
• Components of the Model:– Materials, Labor, Capital Equipment– Detailed Labor Breakdown by major operation– Reports: SAND2013-2733 & SAND2013-2734
One example: An analysis of labor costs shows the growth in labor hours for area-driven manufacturing tasks such as paint prep and paint as blades grow longer.
Important Study of Labor Operations Trends with Scale
14
4. Carbon spar (SNL100-01)
SNL100-00: Glass Spar SNL100-01: Carbon Spar
Cross-sections at 14.6m station
• Spar width reduced by 50%
• Shear web thickness reduced by 25%
• 35% weight reduction
Carbon blade weight and cost baseline established (using SNL
Blade Cost Model)
5. Advanced core material (SNL100-02)
Performance Focus:• Balsa in critical buckling areas• PET foam (recyclable) in non-critical buckling areas and shear webs• ~20% additional weight reduction
Secondary Benefit:• Eco-friendly core materials approach (regrowable and recyclable)
Primary and secondary weight reduction benefits; Recyclable foam has good potential for large blade applications
6. Flatback airfoils/Slenderness Study (SNL100-03)
Focused on effect and limits of blade slenderness
Opportunity to reverse many trends, including:• Weight growth – innovative weight projection anticipated• Buckling• Flutter, Deflection, Fatigue• Surface Area Driven Labor Operations
Increasing Slenderness
Increased blade slenderness has advantages and
disadvantages – these design studies aid in better
understanding the trade-offs
17
Preliminary Design work for SNL100-03 presented in:Griffith, D.T., Richards, P.W., “INVESTIGATING THE EFFECTS OF FLATBACK AIRFOILS AND BLADE SLENDERNESS ON THE DESIGN OF LARGE WIND TURBINE BLADES,” Proceedings of 2014 European Wind Energy Association (EWEA) Annual Event, Barcelona, Spain, March 2014, Paper # 225.
SNL100-02
SNL100-03: Rev0
SNL100-03: Rev1
SNL100-03: Rev2
Geometry Description Baseline DU-Optimized More slender Less SlenderAirfoil Family DU DU Flatbacks Flatbacks