Context: Non-linear Fluid Structure Interaction Main

Final project
(Master level)
Internship proposal – from March 2016
Title: Reduction and interpolation techniques using Proper Orthogonal Decomposition for fast nonlinear Fluid Structure Interaction
Supervisor: Joseph MORLIER ([email protected] ), Nicolas GOURDAIN
([email protected] )
Co-advisor: Elisa Bosco ([email protected]).
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Context: Non-linear Fluid Structure Interaction
A fluid-structure interaction problem requires the solution of the coupled equations of both the fluid
and the structure. This can be computationally highly intensive and extremely time-costly depending
on the complexity of the phenomena to be predicted. Such is the case for structures such as the flap
track fairing (FTF). Their behavior is geometrically highly nonlinear and depends on the source of
excitation. Depending on their position, FTFs can be exposed to high vibrations induced from the
engine exhaust for short periods of time during take-off. Failure to predict these vibration problems
in the design phase causes the necessity for reinforcement and requires servicing actions with
aircraft grounding for repair or replacement of the structure.
In the frame of a PhD launched by Airbus Operations SAS in the A380 program, a method for fluid
structure interaction has been developed using MSC Nastran® as a structural solver and elsA® to
launch aerodynamic computations to generate a database of pressure distribution around the FTF
CFD shape. The dynamic library OpenFSI is customized to couple structure and the database of
pressure. This method has been tested using a reduced order structural finite element model of the
FTF and 2D extruded simplified FTF shape for aerodynamic computations.
Main objectives: Extension to the use of a 3D complex FTF aerodynamic shape.
In order for the aeroelastic loop to support complex 3D aerodynamic shapes there is the necessity to
develop a tool to reduce in dimension the database of aerodynamic pressures with multiple varying
parameters. In order to achieve this goal the Proper Orthogonal Decomposition technique and
Dynamic Mode Decomposition are suggested. A second step will be to develop the appropriate
interpolation technique to reconstruct, starting from the reduced database, the pressure distribution
on the skin of the aerodynamic shape at any position of the latter. A method of interpolation on
manifolds is suggested. The Gram-Schmidt algorithm is recommended to re-orthogonalize the base
after interpolating. The tool will be developed in Python or c++ language and the ca ndidate will be
asked to adapt it to both Windows and Linux environments.
The last step of the training is to integrate the interpolation method in the aero-elastic tool suit, with
the objective to reproduce the FTF unstable behavior. The candidate will be fully integrated in a
multidisciplinary team, included applied mathematicians, physicists and PhD students.
Milestones:
-
-
Bibliographic research to achieve a good understanding of the state of art on the reduction
and interpolation techniques with a focus on Proper Orthogonal Decomposition (POD) and
Dynamic Mode Decomposition (DMD).
Familiarization with the FSI routine.
Development of the reduction/interpolation tool
Integration of the tool in the aeroelastic loop
Required skills:
-
6 months training for a Master degree or equivalent, in fluid mechanics and/or structure
good knowledge in Python and/or C++
good skills in numerical simulation
interest for aeronautics and the space sector
regular meetings are expected so good communication skills are an asset
Bibliography:
[1] Sandboge, R., Fluid-structure interaction with OpenFSI ® and MD Nastran® structural solver, MSC
Software Corporation, 2010
[2] Sadek, R. A., SVD Based Image Processing Applications: State of The Art, Contributions and
Research Challenges, International Journal of Advanced Computer Science and Applications, 2012
[3] Danby, S. J. D., Optimization of Proper Orthogonal Decomposition using Various Preconditioning
Techniques to Analyze Autoignition Simulation Data of Non-Homogeneous Hydrogen-Air Mixtures,
Combustion and Flame 144, 2006
[4] Bui-Thanh, T., Damodaran, M., Willcox, K., Aerodynamic Data Reconstruction and Inverse Design
Using Proper Orthogonal Decomposition, AIAA JOURNAL, Vol. 42, No. 8, August 2004
[5] http://web.stanford.edu/~amsallem/cme345.html
[6] http://www.ece.umn.edu/users/mihailo/software/dmdsp/
[7] http://www.math.tamu.edu/~yvorobet/MATH304-503/Lect3-07web.pdf
[8] http://web.stanford.edu/~amsallem/david_amsallem_phd_thesis.pdf