Aeroelastic Workshop: The Validation of Aeroelastic Simulations - PowerPoint PPT Presentation

Aeroelastic Workshop: The Validation of Aeroelastic Simulations using STAR-CCM+ coupled to Abaqus

The Aeroelastic Workshop Validate the accuracy of STAR-CCM+ coupled to Abaqus for aeroelastic applications The HIRENASD project was chosen as good source of aeroelastic measurement data Performed simulations and analyzed responses:  Aeroelastic equilibrium (fluid-structure coupled)  Modal analysis (structure only, vacuum)  Impulsive loading (fluid-structure coupled)  Prescribed 2 nd bending mode motion (fluid only)  1 st bending mode excitation via prescribed moment applied to structure (fluid-structure coupled) Credit: S. Zhelezov, A. Mueller (CD-adapco)

The HIRENASD Project High Reynolds Number Aerostructural Dynamics (HIRENASD) Funded by the German Research Foundation (DFG) Experiments on an elastic wing model at transonic flight conditions in the European Transonic Windtunnel in Cologne To provide free data on dynamic aeroelastic experiments at conditions typical for large transport aircrafts in cruise flight

The HIRENASD Project Minor mismatch of meshes .cgns file obtained from HIRENASD .bdf file project webpage (trailing edge) Mismatch was corrected to allow for proper mapping cgns: CFD General Notation System bdf: Nastran cells: 5M nodes: 20k .cgns .bdf

The Models STAR-CCM+ 8.5M cells Abaqus 53k nodes

Aeroelastic Equilibrium Configuration (AEC) The AEC AEC is a stable configuration the wing adopts due to the steady aero loads. External and internal forces are in balance (equilibrium).

Aeroelastic Equilibrium Configuration (AEC) Comparison of STAR-CCM+ to experimental results and SOFIA 1) 2) q/E = 0.48E-06, M = 0.8, Re = 23.5E06 CL: Coefficient of Lift CD: Coefficient of Drag AoA: Angle of Attack

Aeroelastic Equilibrium Configuration (AEC) Comparison of STAR-CCM+ to experimental results and SOFIA 2) q/E = 0.48E-06, M = 0.8, Re = 23.5E06

Aeroelastic Equilibrium Configuration (AEC) Comparison of STAR-CCM+ to experimental results and FUN3D 3) q/E = 0.48E-06, M = 0.8, Re = 23.5E06, alpha = 2 ° , station 7, eta = 0.95 STAR-CCM+ FUN3D Cp: Coefficient of pressure

Modal Analysis Modal analysis of structure only (corresponds to vacuum) Reported value Experiment 4) Abaqus model SOFIA model 5) Frequency: 25.75 Hz 26.46 Hz 26.55 Hz Error: 3.15 % 3.11 % 1 st bending mode 2 nd bending mode

Response to impulsive loading Coupled Fluid Structure analysis Reported value STAR-CCM+ Experiment 6) SOFIA model 5) Abaqus Co Sim. Frequency: 29.10 Hz 29.55 Hz 29.54 Hz Error: 1.55 % 1.51 % q/E = 0.48E-06, M = 0.8, Re = 23.5E06, AoA = -1.34 ° , Nitrogen SOFIA 5) STAR-CCM+

Prescribed 2 nd bending mode motion Experiments were performed by exciting the 2 nd bending mode at its resonant frequency Abaqus predicted 2 nd bending mode scaled to match measured wing tip amplitude about the predicted AEC configuration

Prescribed 2 nd bending mode motion Fourier transform of Cp on upper surface at position 7 Experiment 7) and results of STAR-CCM+ simulation (fluid only)

Prescribed 2 nd beding mode motion Fourier transform of Cp on lower surface at position 4 Experiment 7) and results of STAR-CCM+ simulation (fluid only)

1 st bending mode excitation Experiments were performed by exciting the 1 st bending mode at its resonant frequency 2-way coupled simulation with 1 st bending mode moment excitation in structural model q/E = 0.48E-06, M = 0.8, Re = 23.5E06, AoA = -1.34 ° , Nitrogen change in cp relative to tip acceleration -cp ´ /acc 15/1 2) 8) Experiment 2.23E-04 Experiment 2.23E-04 STAR-CCM+ 1.79E-04 SOFIA 1.99E-04 Error 19.73% Error 10.76% -cp ´ / acc 15/1 -cp ´ / acc 15/1 STAR-CCM+ SOFIA Experiment Experiment

References 1) J. Ballmann et al. Aero-structural Dynamics Experiments at High Reynolds Numbers. Springer- Verlag Berlin Heidelberg 2010. Reimer, L., Boucke, A., Ballmann , J., and Behr, M. “Computational Analysis of High Reynolds 2) Number Aero- Structural Dynamics (HIRENASD) Experiments,” IFASD -2009-130, International Forum on Aeroelasticity and Structural Dynamics, Seattle, WA, June 21-25, 2009 3) J.Heeg, J.Florance, P.Chwalowski, B. Perry, C.Wieseman. Information Package: Workshop on Aeroelastic Prediction. Aeroelasticity Branch, NASA Hampton, Virginia. October 2010 H. Korsch, A. Dafnis, H. G. Reimerdes, C. Braun, J. Ballmann , “Dynamic Qualification of the 4) HIRENASD elastic wing model”, Annual Meeting of the German Aerospace Association (DGLR), Paper DGLR-2006-045, Braunschweig, 2006. 5) Reimer, L., Braun, C., Chen, B.-H., Ballmann, J.: Computational Aeroelastic Design and Analysis of the HIRENASD Wind Tunnel Wing Model and Tests. In proc. of the International Forum on Aeroelasticity and Structural Dynamics (IFASD) 2007, Paper IF-077, Stockholm, Sweden, 2007. 6) J.Ballmann et al. Experimental Analysis of High Reynolds Number Aero-Structural Dynamics in ETW, AIAA 2008-841, Presented at the 46th AIAA Aerospace Sciences Meeting and Exhibit, Reno, NV, January 7-10, 2008. Email correspondence with Jennifer Heeg at NASA on 16 th April 2012 regarding updated data for 7) Experiment #271 of the HIRENASD project. 8) J. Ballmann. Aeroelastische Windkanalversuche mit flexiblen Tragfluegeln bei realen Reynoldszahlen (HIRENASD - ASDMAD). Wissenschaftstag DLR Institut FA, Braunschweig, 30.9.2010.

Summary The accuracy of STAR-CCM+ coupled to Abaqus for aeroelastic applications was successfully validated Excellent agreement to the reported experimental data was obtained for all studied cases: • Aeroelastic equilibrium • Modal analysis • Response to impulsive loading • Prescribed 2 nd bending mode motion • 1 st bending mode excitation via prescribed moment applied to structure It was shown that the accuracy of the results obtained with STAR-CCM+ coupled to Abaqus are comparable to specialized aeroelastic codes