Scientific Advisory Page - November, 2009
The advisory panel has been formed to create opportunities for generating ideas, feedback and collaboration while the project is still running, so that we might be able to act on them. To help this process the project is summarised on this page. If you (or colleagues) have the time, then we would be very glad to hear any comments you have on any of this work. Note that the reports linked from this page are in different states of maturity ranging from submitted to journal or conferences (marked ***) to rough ideas we are working on (marked *).
Technical Progress
Structural Variability (linear aerodynamics): Methods to propagate structural variability to linear flutter predictions have been assessed. This paper will appear in Computers and Structures.
paper (***)
Structural Variability (nonlinear aerodynamics): Methods to propagate structural variability to flutter predictions when using CFD level aerodynamics have been developed. The approach relies on the Schur eigenvalue formulation and uses Monte-Carlo, Interval and Perturbation methods. This paper will appear in the Journal of Aircraft.
paper (***)
Structural Damping: The damping identification method has been published and tested on an experimental case.
paper (***)
Aerodynamic Hierarchy: The Schur eigenvalue method has been used to allow the systematic exploitation, updating and sensitivity analysis based on a hierarchy of aerodynamics models (FP, FP/BL, Euler, RANS).
paper (**)
Uncertainty in LCO amplitudes: A model reduction method has been tested for the computation of LCO amplitude under structural parameter uncertainty.
paper (*)
Immediate Plans
Routes for Uncertainty: We are interested in working out the ways in which structural parameter uncertainty influence aeroelastic stability. The Schur eigenvalue framework provides a way of investigating this. The uncertainty can be allowed to influence the normal mode frequencies, the normal modes shapes and the steady state. Mean parameter reduced aerodynamic models are normally used to investigate the influence of variability, which then can only influence the normal mode frequencies. Results are being obtained that show that this can be very misleading. This work will be presented at the SDM conference in Orlando, 2010.
Use of Aerodynamic Hierarchy: Sampling and Co-Kriging are being used to allow a systematic search based on several aerodynamic models. This work will be presented in Orlando at SDM, 2010.
Interval structural model updating: The problem of interval model updating involves the construction of a hypercube containing all the test results. Then the test data is mapped to a hypercube of updating structural parameters using a Meta modal. This approach has been used successfully and a paper is being prepared.
LCO amplitude uncertainty: The work on LCO uncertainty from structural parameters is being extended to systems where the aerodynamics is described by the FP and Euler equations.
Workshop
A workshop is being organised to disseminate the outcomes of the project and to initiate follow-on collaboration. Follow the link in the menu bar for information.
Test Cases
Test cases are now available on the web pages. The Goland wing, generic fighter and Isogai aerofoil all include CFD grids and the structural model. Variability information is also included, along with sample results. Also included is data from variable plate experiments and a damping experiment.
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