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WESEP International ExperienceComputational blade design at Denmark Technical University (DTU) and Braunschweig University of Technology (TU Braunschweig)
Austin J. HerremaIowa State UniversityWind Energy Science, Engineering, and Policy Program (WESEP)Mechanical EngineeringWESEP 594 Seminar, 20 September 2016
RESEARCH BACKGROUND
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Geometry ModelNuMAD: Sandia National Labs
Finite Element AnalysisANSYS
RESEARCH BACKGROUND
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Design Parameters
Geometry Model
(NURBS description)
Analysis Model (Mesh description) Analysis
Results
User-driven design iteration
RESEARCH BACKGROUND
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NURBS
Mesh
Analysis
Tradition
alFEA
Describesgeometry
Mesh-definedinterpolatingfunctionsdefinesolutionfield
NURBS
AnalysisIsogeom
etric
Analysis
Describesgeometryandsolutionfield
RESEARCH BACKGROUND
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Design Parameters
Geometry Model= Analysis Model(NURBS description)
Analysis Results
Optimization algorithm
RESEARCH BACKGROUND
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ClampedB.C.
LoadsfromFAST – no-shear,11.3m/swind
3.25cmE-LT-5500FiberglassFiberglass+1cmSNLTriax
Fiberglass+8.0cmUDCarbon
• Power prediction given by NREL’s FAST• MATLAB’s pattern search algorithm drives optimization
RESEARCH BACKGROUND
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Optimization 1: Tip deflection constrainedOptimization 2: Tip deflection and strain constrained
RESEARCH BACKGROUND
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Proof of concept—can’t trust these results!- Blades don’t have shear
webs- Analysis is performed for
only one wind condition
INTERNATIONAL EXPERIENCE TIMELINE• Fall 2015: Discussions with major professor, confirm interest with
collaborator in Germany• Mid-December 2015: Email DTU Section Head of Aerodynamic Design,
Flemming Rasmussen• “…I am fully funded for this experience and would not require
compensation…”• Response a week later, put in contact with senior researcher Frederik
Zahle to find relevant project• February 2016: Confirm AirBnB housing in Roskilde, Denmark• February 2016: Purchase flights• March 2016: Confirm university guest housing in Braunschweig, Germany• May 27, 2016: Depart for Roskilde, Denmark
• Approximately 7 week stay• July 15, 2016: Take train from Roskilde to Braunschweig
• Approximately 4 week stay• August 13, 2016: Return to Des Moines
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RESEARCH AT DTU• Advanced computational blade design techniques
• IEC standard-based rotor optimization—about 1000 load cases• 10 MW blade design• Close relationships
with Siemens, LM, Vestas
• FUSED-Wind• Collaboration with
NREL• HAWC2 or FAST• Development of
programmatic wrapperfor FAST
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RESEARCH AT DTU
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• Development of FAST wrapper for FUSED-Wind with Katherine Dykes (NREL) and Frederik Zahle (DTU)
RESEARCH AT DTU
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• Parallel execution of FAST cases within OpenMDAO
RESEARCH AT DTU
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BladeDesign
IsogeometricStructuralAnalysis
+OneLoadCase
Results
Optimization
RESEARCH AT DTU
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BladeDesign
IsogeometricStructuralAnalysis
+OneLoadCase
Results
Optimization
BladeDesign
IsogeometricStructuralAnalysis
+ManyLoadCases
Results
Optimization
TU BRAUNSCHWEIG EXPERIENCE
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• Josef Kiendl• Expert on
isogeometric analysis,thin shell analysis
RESEARCH AT TU BRAUNSHWEIG
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12 3
MultipleSurfaces FEAMesh OneSolution
FieldTraditional
FEA
IsogeometricAnalysis
MultipleSurfaces
MultipleSolutionFields
RESEARCH AT TU BRAUNSHWEIG
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𝑊" = 𝛾% (𝑎() * 𝑎(+ − 𝑎()̇ * 𝑎(+̇)/𝑑𝑠 = 03
a3 =normalunitvector
Undeformedconfiguration
Deformedconfiguration
A
B
A
B
𝑎()
𝑎(+
𝑎()̇
𝑎(+̇
ΓΓ
𝑎() * 𝑎(+ = 𝑎() 𝑎(+ cos 𝜃 = cos(𝜃) (anglebetweentwopatches)
𝑎()̇ * 𝑎(+̇ = 𝑎()̇ 𝑎(+̇ cos �̇� = cos(�̇�)
RESEARCH AT TU BRAUNSHWEIG
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Eachgausspoint:1) Projectcurvegausspointtoeachpatch2) Calculatenormalvectors3) Calculatepenaltycontribution4) Assembletoglobaldegreesoffreedom
SUMMARY• Highly recommend taking advantage of opportunity!
• Beneficial to research• Beneficial for networking• Beneficial to résumé/CV
• Creates opportunities to experience new places
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Rome Malmö, Sweden
Berlin London
TIPS
• Check with DTU if you’re interested!• Try to have a good idea of what work you will accomplish
beforehand, but be flexible• Don’t be afraid to ask questions• Travel insurance – Iowa State Study Abroad
• Danette Bontrager• Register trip with U.S. Department of State
• step.state.gov• Consider AirBnB for housing needs – good to have
another local contact
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