22nd Congress of International Council of the Aeronautical Sciences, Harrogate, UK, 28 August - 1st September, 2000
Paper ICAS 2000-2.11.1
NUMERICAL OPTIMIZATION OF ADAPTIVE TRANSONIC AIRFOILS WITH VARIABLE CAMBER
A. Sommerer, T. Lutz, S. Wagner
University of Stuttgart, Germany
Keywords: numerical optimisation, transonic flow, shock control bump, variable camber,
adaptivewing
A special research group (SFB 409) has been established
at Stuttgart University to investigate the
potential of adaptive structures for aerospace application.
One project deals with concepts and aerodynamics
of adaptive transonic wings. To cope with
the problem of flight at transonic Mach numbers
adaptive mechanisms are introduced. Aerodynamic
efficiency at off-design conditions is
improved by the application of a shock control
bump (SCB) on a variable camber (VC) airfoil.
Since a SCB has to be properly shaped and positioned
to generate a favourable effect, relevant
geometrical parameters were investigated using
direct numerical optimisation. An optimisation
environment was developed consisting of a hybrid
optimiser, a geometry module and a coupled
Euler boundary-layer code. For a specified offdesign
condition bump shapes were optimised,
while the influence of various geometric bump
representations was investigated. Shape optimisations
for an adaptive bump were carried out for
different Mach numbers at a fixed lift coefficient.
To overcome the problem of narrow Mach regions
of significant drag reduction for one-point
designed bumps, multi-point designs were performed.
Finally a VC-SCB combination was numerically
optimised in order to improve the performance
for several off-design conditions.
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