Horizontal Flight Dynamics Simulations using a Simplified Airplane Model and Considering Wind Perturbation

An in-house method of Newton-Euler inverse dynamics guidance based on a simplified airplane model in horizontal flight was proposed in a previous paper presented at NMAS 2018 workshop [1]. The goal was to guide the airplane between two locations situated at 100 km distance in the horizontal plane, considering some simplifying assumptions: the airplane was considered a material point (no motion equations involving torques are considered here); the thrust was constant in magnitude during the entire motion; the airplane is inclined at time t with the rolling angle (t); the main parameter for controlling the flight path was considered to be the sideslip angle (angle between the thrust vector and the velocity vector); the lift force balanced the weight, the centrifugal force and the wind perturbation lateral force; the wind perturbation was considered linear by pieces of 10 km distance. So, the horizontal flight guidance parameter is the sideslip angle , while the rolling angle is determined from the condition that the flight remains in the horizontal plane, which has to be permanently fulfilled. This paper presents several simulations validating the proposed inverse dynamics guidance tool for airplane horizontal flight. Various wind perturbation possibilities have been tested, considering this wind perturbation as linear by pieces during the horizontal flight. In conclusion, this guidance method worked well for the simplified horizontal flight case study

Considerations Regarding the Influence of the Mechanical Vibrations Upon a Dynamic System Used in Tobacco Industry

Abstract: -The paper analyses, from the point of view of the mechanical vibrations, the apparatus of transporting and drying of tobacco leaves. The technical literature studies a reduced number of types of such apparatuses, which are an important component of the technological process of cigarette production. In the present paper, fundamental knowledge applied to a model of the driving gear and to a model of the transport system, respectively, of such an apparatus, allows it to obtain some graphical representations, useful to determine its vibratory behavior

Influence of drag force upon the shortest time trajectory of an aircraft

The shortest time trajectory of an aircraft between two given locations is determined using a simple mathematical model. By taking into account the drag force (viscous friction force with the air), a problem of variational calculus is obtained which consists in determining two functions that minimize a functional, subject to a non-holonomic constraint. The trajectory is determined directly, by numerical integration of Euler equations with multipliers. Three types of drag forces were considered: constant, linear and quadratic. The results are verified through comparison to the values obtained from numerical minimization of the involved functional approximate forms