WESEP International Experience Computational blade design at Denmark Technical University (DTU) and Braunschweig University of Technology (TU Braunschweig)
Austin J. Herrema Iowa State University Wind Energy Science, Engineering, and Policy Program (WESEP) Mechanical Engineering WESEP 594 Seminar, 20 September 2016 RESEARCH BACKGROUND
Geometry Model Finite Element Analysis NuMAD: Sandia National Labs ANSYS
Austin Herrema – Iowa State University 2 RESEARCH BACKGROUND
Geometry Analysis Model Design Model (Mesh description) Analysis Parameters (NURBS description) Results
User-driven design iteration
Austin Herrema – Iowa State University 3 RESEARCH BACKGROUND
NURBS Describes geometry
Mesh-defined Mesh interpolating functions define solution field Traditional FEA
Analysis Describes geometry NURBS and solution field Analysis
Isogeometric Analysis
Austin Herrema – Iowa State University 4 RESEARCH BACKGROUND
Geometry Model Design = Analysis Model Analysis Parameters (NURBS description) Results
Optimization algorithm
Austin Herrema – Iowa State University 5 RESEARCH BACKGROUND
Austin Herrema – Iowa State University 6 RESEARCH BACKGROUND
Austin Herrema – Iowa State University 7 RESEARCH BACKGROUND
Loads from FAST – no-shear, 11.3 m/s wind
Clamped B.C. Fiberglass + Fiberglass + 1 cm SNLTriax 8.0 cm UD Carbon 3.25 cm E-LT-5500 Fiberglass
• Power prediction given by NREL’s FAST • MATLAB’s pattern search algorithm drives optimization
Austin Herrema – Iowa State University 8 RESEARCH BACKGROUND
Optimization 1: Tip deflection constrained Optimization 2: Tip deflection and strain constrained
Austin Herrema – Iowa State University 9 RESEARCH BACKGROUND
Proof of concept—can’t trust these results! - Blades don’t have shear webs - Analysis is performed for only one wind condition
Austin Herrema – Iowa State University 10 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
Austin Herrema – Iowa State University 11 ROSKLIDE, DENMARK
Austin Herrema – Iowa State University 12 ROSKLIDE, DENMARK
Austin Herrema – Iowa State University 13 ROSKLIDE, DENMARK
Austin Herrema – Iowa State University 14 ROSKLIDE, DENMARK
Austin Herrema – Iowa State University 15 ROSKLIDE, DENMARK
Austin Herrema – Iowa State University 16 ROSKLIDE, DENMARK
Roskilde Train Station
Austin Herrema – Iowa State University 17 HOUSING IN ROSKILDE
Austin Herrema – Iowa State University 18 HOUSING IN ROSKILDE
Austin Herrema – Iowa State University 19 HOUSING IN ROSKILDE
Austin Herrema – Iowa State University 20 HOUSING IN ROSKILDE
Austin Herrema – Iowa State University 21 Austin Herrema – Iowa State University 22 DTU EXPERIENCE
Austin Herrema – Iowa State University 23 DTU EXPERIENCE
Austin Herrema – Iowa State University 24 DTU EXPERIENCE
Austin Herrema – Iowa State University 25 DTU EXPERIENCE
Austin Herrema – Iowa State University 26 DTU EXPERIENCE
Austin Herrema – Iowa State University 27 OTHER THINGS IN DENMARK
Austin Herrema – Iowa State University 28 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 wrapper for FAST
Austin Herrema – Iowa State University 29 RESEARCH AT DTU • Development of FAST wrapper for FUSED-Wind with Katherine Dykes (NREL) and Frederik Zahle (DTU)
Austin Herrema – Iowa State University 30 RESEARCH AT DTU
• Parallel execution of FAST cases within OpenMDAO
Austin Herrema – Iowa State University 31 RESEARCH AT DTU
Isogeometric Blade Structural Analysis Results Design + One Load Case
Optimization
Austin Herrema – Iowa State University 32 RESEARCH AT DTU
Isogeometric Blade Structural Analysis Results Design + One Load Case
Optimization
Isogeometric Blade Structural Analysis Results Design + Many Load Cases
Optimization
Austin Herrema – Iowa State University 33 TRIP TO BRAUNSCHWEIG
Austin Herrema – Iowa State University 34 TRIP TO BRAUNSCHWEIG
Austin Herrema – Iowa State University 35 BRAUNSCHWEIG, GERMANY
Austin Herrema – Iowa State University 36 BRAUNSCHWEIG, GERMANY
Austin Herrema – Iowa State University 37 BRAUNSCHWEIG, GERMANY
Austin Herrema – Iowa State University 38 BRAUNSCHWEIG, GERMANY
Austin Herrema – Iowa State University 39 BRAUNSCHWEIG, GERMANY
Austin Herrema – Iowa State University 40 HOUSING IN BRAUNSCHWEIG
Austin Herrema – Iowa State University 41 HOUSING IN BRAUNSCHWEIG
Austin Herrema – Iowa State University 42 HOUSING IN BRAUNSCHWEIG
Austin Herrema – Iowa State University 43 TU BRAUNSCHWEIG EXPERIENCE
Austin Herrema – Iowa State University 44 TU BRAUNSCHWEIG EXPERIENCE
Austin Herrema – Iowa State University 45 TU BRAUNSCHWEIG EXPERIENCE
• Josef Kiendl • Expert on isogeometric analysis, thin shell analysis
Austin Herrema – Iowa State University 46 RESEARCH AT TU BRAUNSHWEIG
Austin Herrema – Iowa State University 47 RESEARCH AT TU BRAUNSHWEIG
1 2 3
Traditional Multiple One Solution FEA Mesh FEA Surfaces Field
Isogeometric Multiple Multiple Analysis Surfaces Solution Fields
Austin Herrema – Iowa State University 48 RESEARCH AT TU BRAUNSHWEIG
Deformed Undeformed configuration configuration
̇ ̇ � = � (� � − � � ) �� = 0 a3 = normal unit vector
� � = � � cos � = cos (�) (angle between two patches) ̇ ̇ ̇ ̇ ̇ ̇ � � = � � cos � = cos (�)
B B
̇ � �
̇ � Γ � A Γ A Austin Herrema – Iowa State University 49 RESEARCH AT TU BRAUNSHWEIG
Each gauss point: 1) Project curve gauss point to each patch 2) Calculate normal vectors 3) Calculate penalty contribution 4) Assemble to global degrees of freedom
Austin Herrema – Iowa State University 50 RESEARCH AT TU BRAUNSHWEIG
Clamped B.C.
Force
Austin Herrema – Iowa State University 51 RESEARCH AT TU BRAUNSHWEIG
Austin Herrema – Iowa State University 52 SUMMARY
• Highly recommend taking advantage of opportunity! • Beneficial to research • Beneficial for networking • Beneficial to résumé/CV • Creates opportunities to experience new places
Rome Malmö, Berlin London Sweden
Austin Herrema – Iowa State University 53 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
Austin Herrema – Iowa State University 54 Thank you! QUESTIONS
Austin Herrema – Iowa State University 55