Search Results

In this paper, it is developed a descriptive theory of paraglider flight mechanics, a gliding aircraft designed for entertainment purposes. After the analytical representation of the equipment geometry, the equations of longitudinal motion are derived and the most relevant parameters of performance and stability are identified. The developed theory is tried out based on real gliders analysis showing consistent results. The theoretical results here presented about paraglider flight mechanics can not be found in the available bibliography. It's expected that a scientific approaching of the paraglider stability and performance, as a branch in the aeronautic engineering field enables relevant improvements on flying and safety characteristics of these unconventional aircrafts.

In this work, sailplane symmetrical motion equations including pitch motion controlled by elevator angle are presented. The following effects are especially taken into consideration: i) tail damping due to pitch motion; ii) air density variation according to altitude; iii) presence of vertical and horizontal atmospheric air motions, and iv) non-linearity of CL ′ a curve near stall angle. The mathematical modeling includes the construction of an objective function for competition flight optimization. Making use of the concept of state variables, the minimum time trajectory problem is formulated as an optimal control problem with state constraints. Using simplified control laws and a mathematical programming algorithm, suboptimal trajectories are obtained for the sailplane PIK-20B.

Using a Simple Genetic Algorithm, the present paper obtains the optimal geometry of a cam with roll follower. In order to evaluate cam performance, an objective function which takes into account the influence of the inertia, the perimeter and of the pressure angle is proposed. The choice for a Genetic Algorithm is justified because, in preliminary tests, the objective function had proven to be multimodal