21st Congress of International Council of the Aeronautical Sciences, Melbourne, Australia, 13-18 September, 1998
Paper ICAS-98-2.3.4

A SIMPLE WING OPTIMISATION CODE INCLUDING PROPELLER EFFECTS

Veldhuis L. L. M., Heyma P. M.
Delft University of Technology, The Netherlands

Keywords: wing optimization, propeller effects

To further analyze the possibilities of optimized designs a simple and fast calculation method for optimal lift distributions of tractor propeller/wing configurations is formulated and discussed. The optimization algorithm is based on a Trefftz-plane analysis where the conservation laws of mass, momentum and energy are fulfilled in a control volume surrounding the configuration. The paper discusses the formulation of the optimization algorithm based on augmented Lagrange integrals. The effect of viscous effects is incorporated in the calculation process. The method described above was implemented in a computer program which enables the user find the optimum lift distribution for minimum drag for any tractor propeller / wing arrangement of arbitrary shape. As input for the slipstream data the user can either select input of experimental data or generate artificial data using a simple slipstream model based on the well known blade element theory with Prandtl tip loss factor. Some numerical studies, show that optimization of a modern medium speed turboprop aircraft (Fokker-50 like configuration) leads to performance increase by adapting the wing geometry and twist distribution.

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