Numerical Simulation of Manoeuvring Aircraft by Aerodynamic and Flight-Mechanic Coupling

This paper presents results of simulations performed within the scope of the DLR-Project AeroSUM- “Aerodynamic Simulation of Unsteady Manoeuvres”. The objective of the AeroSUM-Project is to develop a numerical tool to simulate the unsteady aerodynamics of a free flying aircraft, by use of coupled aerodynamic and flight-mechanic computations. To achieve this objective, the unstructured, time accurate CFD flow-solver Tau is coupled with a computational module solving the flight-mechanic equations of motion. By use of an overlapping grid technique (chimera), simulations of a complex configuration with movable control-surfaces is possible. Results of static calculations are presented to show the basic aerodynamics of the vortex dominated flowfield of the delta wing. The static simulation cases also serve as starting solutions for the unsteady simulations. Results of the unsteady manoeuvre simulations are divided into guided motion and freeflight motion. For the guided motion an oscillating motion with a given frequency and amplitude is presented. For the free-flight motion, the following cases are presented: free-to-roll from a non-zero initial roll-angle (without flap deflection), and free-to-roll initiated by flap deflection from an initial rollangle of zero. These calculations demonstrate the functionality of the simulation system. A 65-degree cropped delta wing model, with fuselage and movable trailing edge flaps, is used to gather experimental data. Several forced and free-to-roll experiments around the body fixed axes, both with and without flap deflection, are performed in order to validate the computational results obtained with the simulation tool

Design and testing of low noise landing gears

In the approach phase of large commercial aircraft, airframe noise - and in particular that from landing gears - is one of the dominant aircraft noise components. Within a European co-financed research project entitled "Significantly Lower Community Exposure to Aircraft Noise" (codenamed SILENCER) a study in "advanced low noise landing gear design" was performed to develop operational landing gears which take into account aeroacoustic constraints early in the design stage. Airbus aircraft typical configurations of low wing with underslung engines and A340 type gears were selected as reference. RANS flow field calculations were performed and used to identify and thus avoid the impingement of high speed flow onto critical gear structure elements. The evaluation of CFD results with respect to the effects on aerodynamic noise was performed on the basis of related experimental experience and a semi-empirical landing gear noise model. Both low noise advanced nose and main landing gears were designed and manufactured at full scale for noise testing in the 8 m by 6 m open test section of the German-Dutch Wind Tunnel (DNW-LLF). Relative to the conventional reference gears a reduction of broadband landing gear noise in the order of 5 to 6 dB (i.e. on source level) was achieved

Bundesarbeitsgemeinschaft Schulpraktische Studien (BaSS)

Mochalski A, Lüdecke M, Schöning A, Walke J, Diehr F. Bundesarbeitsgemeinschaft Schulpraktische Studien (BaSS). In: Bendick C, Feldmann H, Horstmeyer J, et al., eds. Netzwerke: Magazin zu gelingender Bildungsnetzwerkarbeit der Zentren für Lehrer*innenbildung und Schools of Education. Braunschweig; 2020: 62-68