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For the planned optimization of the vertical tailplane (VTP) of a Megaliner transport aircraft configuration a prior basic study is undertaken where the influence of simplifying the aircraft geometry on the characteristics of the VTP is examined. Four different configurations with varying simplification level were investigated. These are: a VTP on a base plate, a VTP on a fuselage, a VTP on a fuselage with horizontal tailplane and a VTP on a fuselage with horizontal tailplane, wing and belly fairing. Several flight cases were identified where the characteristics of the VTP are most important and then analyzed by means of numerical flow analysis using the flow solver TAU developed at the German Aerospace Center DLR. Determined are the side force coefficient generated at maximum rudder deflection, the high speed drag, the gradient of the side force coefficient due to rudder deflection and the gradient of the side force coefficient due to sideslip angle. The latter two were evaluated at low and high speed conditions. The simplified configurations were then compared to the most complete one as reference case.

The application and effectiveness of MO surge arresters to capacitor banks is discussed. Principle application rules for different configurations are given. The influence of MO arresters with different ratings on voltage and current at the capacitors and at a re-striking circuit breaker respectively is shown and quantified.

The purpose of this paper is to describe the development of a field panel method for the aerodynamic design of transonic aircraft configurations. The method is based on the full-potential equation which is solved on the basis of a BEM formulation. The problem is reduced to a system of two nonlinear integro-differential equations for the disturbance potential in the field and the singularity distribution on the body surface. An iteration procedure incorporating the boundary element method to satisfy the Dirichlet boundary condition on the body was coupled with a modular extension to account for nonlinear compressibility effects (including weak shock waves). Several methodical enhancements like an adaptive field mesh have been derived to make the practical application of the method more feasible. The procedure described has the potential to extend an arbitrary panel method modular to account for transonic compressibility effects. Preliminary calculation results are presented.