Research of the influence of the volumetric-mass layout of the aircraft on the dynamics of rotational motion in the longitudinal plane

Abstract

In this paper, the influence of the volumetric-mass layout of the aircraft on the dynamics of rotational motion in the longitudinal plane is considered. The studies allow us to evaluate the relationship between the space-mass layout of the aircraft and the perturbing aerodynamic effects that occur during the transition process. The deviation of the empirical values of the aerodynamic moment from the linear dependence and the time of the transition process were considered to be quantitative estimates of the quality of the transient process. An original aerodynamic experiment with a moving aircraft model was proposed as a research method. The continuous change in the position of the aerodynamic model in the experiment made it possible to analyze the effects and their influence on the motion parameters in real time, and take into account the unsteadiness of the flow on the airframe surface. The conducted experiment shows that to reduce the time of the transient process, the value of the moment of inertia of the aircraft should be reduced but, in this case, the aerodynamic moments caused by the inertia of the medium and various unsteady flows will increase. As a result, when choosing the ratios of stability and controllability of an aircraft, one should pay attention not only to the geometric location of the center of mass and focus of the aircraft, but also to the mass-volume characteristics of the aircraft.