International Journal of Aviation Science and Technology

International Journal of Aviation Science and Technology Kapağı
Yayıncı
Sürdürülebilir Havacılık Araştırma Derneği
e-ISSN
2687-525X
Başlangıç Yılı
2020
Dil
İngilizce
Durumu
Aktif
Dizin
Havacılık Dizini
Yayın Aralığı
Yılda 2 Sayı

Son Sayı (Latest Issue) - Year 2022 Volume 03 Issue 01

Abstract (Özet)

Thanks to its typical limited speeds and altitudes, Urban Air Mobility represents an interesting application for electric and hybrid-electric power systems. In addition, short-range requirements are compatible with limited performance of today batteries, conversely to their current inapplicability for commercial aviation purposes. For the present study, a parallel Hybrid Electric Propulsion System for a coaxial-rotor Air Taxi has been implemented in Simulink and tested on four different sets of operating conditions, with a transient signal as input for Power Lever Angle command. The goal of this investigation is to analyse transient behaviour of the hybrid electric propulsion system in question, to underline the role of electric motors in assisting thermal engine during transients, and, in particular, it focuses on the benefits deriving from the adoption of a coordination block which adapts torque split between the two power sources on the basis of actual engine response.

Abstract (Özet)

Analyzing the flight quality of an aircraft obliges the examination of the natural stability of the system. In this paper, the frequency domain response of the F-16 aircraft dynamics is analyzed with performed Simulink models considering two different trimming conditions because the frequency-domain methods have many distinct and important advantages compared to time-domain methods. The nonlinear model is established by utilizing aerodynamic, propulsive, and atmospheric databases. Then, the trim analysis for cruise flight is performed to obtain trim parameters and, the aircraft is also linearized numerically. From the linearized dynamics for each trim condition, transfer functions are obtained for each input. Subsequently, to obtain information on the dynamic behavior of the aircraft, the linear model is inspected in the frequency domain. Finally, flight quality analysis was investigated by considering the lateral and longitudinal modes of the aircraft, accordance with international standards.

Abstract (Özet)

The aim of this work is to design a control system based on modern control methods to control flight formations of quadrotor unmanned aerial vehicles. A leader-follower methodology is implemented where the leader vehicle has some predefined trajectory and the follower vehicles are controlled in order to track the leader keeping a constant displacement. The formation control system, responsible for the vehicle formation, considers, at first, only the motion at constant height, and secondly, the three-dimensional motion. In both cases, the nonlinear control laws are derived based on Lyapunov stability theory and the Backstepping method. The control laws are validated in simulation resorting to a realistic environment and vehicle models.

Abstract (Özet)

Due to their inventiveness in achieving high speeds while maintaining excellent agility, high-speed UAVs will be an interesting field of study in today's aviation technology. In this study, modeling and control of a fixed-wing high-speed UAV are performed. Geometric design and aerodynamic analysis are executed of the UAV with the help of some CFD software. Flight performance after a doublet control surface disturbance is evaluated with 6DOF flight simulations in both longitudinal and lateral directions by a developed MATLAB/Simulink code. Two kinds of different linear controllers, which are PID and LQR-I, are designed to hold the pitch angle of the UAV in the desired value. The time responses of the controllers are represented, and the elevator deflection effort is evaluated. Finally, a compulsive pitch angle is wanted to be tracked by the two controllers, and their responses are compared in terms of performance and stability.

Abstract (Özet)

This paper presents the wing design and structural analysis of a single turboprop aircraft with a maximum takeoff weight of 2,200 lbs. The wing structure of the aircraft is a conventional mid-wing configuration of a twisting trapezoidal planform with an aspect ratio of 0.6. The analysis involved determining the loads acting on the wing structure. That is the aircraft’s flight envelope and the wing’s critical loading condition according to Title 14 Code of Federal Regulations Part 23 (14 CFR Part 23). The wing CAD model, composed of the aircraft wing components of the spar, ribs, and skins including its layout, was developed, and analyzed based on available 7075T6 Aluminum sheets using the SolidWorks software. The results for the wing’s critical loading condition showed that the wing tip displacement was less than 5% of the half-wingspan with a margin of safety of 0.5 and mass of 117.97 lbs which was less than the expected mass of 132 lbs.