Flight Dynamic Investigations of a Blended Wing Body Aircraft

Autor: Christoph Neubacher



This thesis deals with stability investigations and a motion simulation of a non conventional aircraft configuration. The investigated aircraft of this thesis is called AC 20.30 and is a Blended Wing Body model aircraft, which was designed by a research group of students of the University of Applied Science Hamburg. The stability investigations of the AC 20.30 should show, if the aircraft is statically and dynamically stable for the longitudinal and lateral motion. The aircraft stability can be computed with the help of the stability derivatives computed with the aerodynamic coefficients measured in the Wind tunnel Dresden. As a result of the stability investigation, the AC 20.30 shows for two characteristics motion modes of the longitudinal motion, the Phugoid mode and the Short Period mode, dynamically stable behaviour. The stability investigation for the lateral motion results in dynamically stable flight characteristics for the Roll and Dutch Roll mode, while the AC 20.30 is dynamically unstable for the Spiral mode. Additional to the stability investigation the AC 20.30 is investigated for its flight characteristic and is classified into flight levels. The AC 20.30 shows for the longitudinal motion level 1 flight characteristics, while the flight characteristics for the lateral motion are between level 1 and 2. The motion simulation of the AC 20.30 takes place in the Matlab Simulink environment. It should simulate, how the AC 20.30 acts in its different motion directions, if the control surfaces are deflected or if suddenly appearing gusts affect the aircraft. The simulation should also show, whether or not the aircraft is able to damp out the mentioned disturbances in the motion directions.