Analysis and Simulation of UAV Aircraft Flight Dynamics

2014 ◽  
Vol 915-916 ◽  
pp. 7-11
Author(s):  
Tariq O. Mohammed ◽  
Naser M. Elkhmri ◽  
Hamza AboBakr
Keyword(s):  
Dynamic Stability ◽  
Incompressible Flow ◽  
Equations Of Motion ◽  
Flight Dynamics ◽  
Unmanned Aircraft ◽  
Aircraft Flight ◽  
Flying Qualities ◽  
Static And Dynamic Stability ◽  
Level 1 ◽  
The Stability

The objective of the present work is to evaluate the static and dynamic stability of the Flying Wing Unmanned Aircraft Vehicle (UAV) model using the Tornado software. The longitudinal and the lateral-directional aerodynamics were studied using the model with incompressible flow, asymmetric, conditions. The stability coefficients were calculated and give proof that the aircraft is statically stable. Using the stability coefficients, the longitudinal and lateral-directional equations of motion were written to evaluate the dynamic stability of the vehicle. Good flying qualities were obtained, rating in Level 1 for the Cooper and Harper scale.

An Analysis of the Static and Dynamic Stability of an Hypersonic Transport Aircraft Longitudinal Motion Flying at Hypersonic Speeds and Various Heights

2012 ◽  
Author(s):  
D. Mclean ◽  
Z.A. Zaludin ◽  
P.R. Arora
Keyword(s):  
Mathematical Model ◽  
Dynamic Stability ◽  
Static Stability ◽  
Longitudinal Motion ◽  
Transport Aircraft ◽  
Static And Dynamic Stability ◽  
Hypersonic Speeds ◽  
Scramjet Engine ◽  
The Stability ◽  
Engine Condition

Suatu kajian tentang kestabilan statik dan dinamik pesawat pengangkutan hipersonik hipotesis telah dilakukan dengan menggunakan model matematik untuk pergerakan membujur semasa penerbangan di keadaan penerbangan yang berlainan. Hasil daripada analisis kestabilan menunjukkan bahawa pesawat tersebut akan menjadi lebih tidak stabil apabila penerbangan di nombor Mach dan ketinggian yang lebih tinggi daripada keadaan penerbangan nominal. Juga disertakan di sini keadaan enjin scramjet apabila pesawat ini terbang pada kelajuan hipersonik dan ketinggian yang berlainan. Kata kunci: dinamik pesawat; kestabilan dinamik; kestabilan statik; enjin scramjet A study of the static and dynamic stability of an hypothetical hypersonic transport aircraft was conducted based on a mathematical model of the longitudinal motion of the aircraft flying at a number of different flight conditions. The result from the stability analysis has shown that the aircraft becomes even less stable at higher Mach numbers and heights than the nominal flight condition. Also discussed here is the scramjet engine condition when the aircraft was simulated to be flying at hypersonic speeds and different heights. Key words: aircraft dynamics; dynamic stability; static stability; scramjet engine

On the Dynamic Stability of Self-Aligning Journal Gas Bearings

1977 ◽  
Vol 99 (4) ◽  
pp. 434-440 ◽  
Author(s):  
M. J. Cohen
Keyword(s):  
Dynamic Stability ◽  
Journal Bearing ◽  
Equations Of Motion ◽  
Stability Boundary ◽  
Initial Condition ◽  
Small Motion ◽  
Gas Bearings ◽  
Loading Case ◽  
The Stability ◽  
Small Disturbances

The report presents an investigation of the dynamic stability behaviour of self-aligning journal gas bearings when subjected to arbitrary small disturbances from an initial condition of operational equilibrium. The method is based on an approach similar to the nonlinear-ph solution of the author for the quasi-static loading case but the equations of motion of the journal are the linearized forms for small motion in the two degrees (translational) of freedom of the journal center. The stability domains for the infinite journal bearing are presented for the whole of the eccentricity (ε) and rotational speed (Λ) ranges for any given bearing geometry, in the shape of stability boundaries in that domain. It is shown that a given bearing will be stable within a corridor in the (ε, Λ) parametral domain having as its lower bound the so called “half-speed” whirl stability boundary and as its upper bound another whirling instability at a higher characteristic (relative) frequency, the instability occurs generally at the higher eccentricities and lower rotational speeds.

Static and Dynamic Stability Analysis of a Rotating Taper Beam Having Elliptical Cross Section Subjected to Pulsating Axial Load With Thermal Gradient

2019 ◽  
Vol 24 (3) ◽  
pp. 440-450
Author(s):  
Madhusmita Pradhan ◽  
Mrunal Kanti Mishra ◽  
Pushparaj Dash
Keyword(s):  
Dynamic Stability ◽  
Cross Section ◽  
Thermal Gradient ◽  
Axial Load ◽  
Equations Of Motion ◽  
Elliptical Cross Section ◽  
Energy Principle ◽  
Elliptical Cross ◽  
Static And Dynamic Stability ◽  
Hill’S Equations

The static and dynamic stability of a rotating tapered beam having an elliptical cross-section subjected to a pulsating axial load with a thermal gradient is investigated under three different boundary conditions, such as clampedclamped (C-C), clamped-pinned (C-P), and pinned-pinned (P-P). The governing equations of motion have been derived by using Hamilton’s energy principle. A set of Hill’s equations have been obtained by the application of generalized Galerkin’s method. The effects of taper parameter, hub radius, rotational speed, thermal gradient, and geometric parameter on the static buckling loads and the regions of instability have been studied and the results are presented graphically

Dynamic Stability Characteristics of Axially Accelerated Beams

2006 ◽  
Vol 321-323 ◽  
pp. 1654-1658 ◽  
Author(s):  
Hong Hee Yoo ◽  
Sung Jin Eun
Keyword(s):  
Dynamic Stability ◽  
Natural Frequencies ◽  
Equations Of Motion ◽  
Stability Diagram ◽  
Accelerated Motion ◽  
Stability Diagrams ◽  
Divergence Type ◽  
The Stability ◽  
Direct Numerical Integration ◽  
Free Beam

Dynamic stability of axially accelerated beams is investigated in this paper. The equations of motion of a fixed-free beam undergoing axially accelerated motion are derived. Unstable regions due to the acceleration are obtained by using the Floquet’s theory. Stability diagrams are presented to illustrate the influence of the acceleration characteristics. Large unstable regions of flutter type instability exist around the first, twice the first, and twice the second bending natural frequencies. Divergence type instability also occurs when the acceleration exceeds a certain value. The validity of the stability diagram is confirmed by direct numerical integration of the equations of motion.

Dynamic Stability of a Spinning Timoshenko Beam Subjected to a Moving Mass-Spring-Damper Unit

2010 ◽  
Author(s):  
T. H. Young ◽  
M. S. Chen
Keyword(s):  
Dynamic Stability ◽  
Timoshenko Beam ◽  
Multiple Scales ◽  
Equations Of Motion ◽  
Axial Direction ◽  
Longitudinal Axis ◽  
Moving Mass ◽  
The Stability ◽  
The Galerkin Method ◽  
Mass Spring

This paper investigates the dynamic stability of a finite Timoshenko beam spinning along its longitudinal axis and subjected to a moving mass-spring-damper (MSD) unit traveling in the axial direction. The mass of the moving MSD unit makes contact with the beam all the time during traveling. Due to the moving MSD unit, the beam is acted upon by a periodic, parametric excitation. In this work, the equations of motion of the beam are first discretized by the Galerkin method. The discretized equations of motion are then partially uncoupled by the modal analysis procedure suitable for gyroscopic systems. Finally the method of multiple scales is used to obtain the stability boundaries of the beam. Numerical results show that if the displacement of the MSD unit is equal to only one of the two transverse displacements of the beam, very large unstable regions may appear at main resonances.

scholarly journals Static and Dynamic Stability Analysis of an Asymmetric Rotating Tapered Sandwich Beam Subjected to Pulsating Axial Load with Thermal Gradient

2019 ◽  
Vol 24 (4) ◽  
pp. 665-676
Author(s):  
Madhusmita Pradhan ◽  
Pushparaj Dash
Keyword(s):  
Boundary Conditions ◽  
Dynamic Stability ◽  
Thermal Gradient ◽  
Axial Load ◽  
Equations Of Motion ◽  
Core Loss ◽  
Sandwich Beam ◽  
Density Parameter ◽  
Static And Dynamic Stability ◽  
Elastic Layers

The static and dynamic stability of an asymmetric rotating tapered sandwich beam subjected to pulsating axial load in temperature environment is studied under two different boundary conditions. The non-dimensional equations of motion and the boundary conditions are derived by applying Hamilton's energy principle. A coupled Hill's equations with complex coefficients are derived from the non-dimensional equations of motion by the application of the generalized Galerkin method. By the application of the Saito-Otomi conditions, zones of instabilities are obtained and presented graphically. For the calculation of the Young's module for the elastic layers, the effect of temperature has been taken in to consideration by means of a uniform thermal gradient along the longitudinal axes for both the upper and lower elastic layers. The effects of the taper parameter, core loss factor, thermal gradient, rotational speed, hub radius, and core density parameter on the static buckling loads and the regions of instability are investigated.

Study of Static and Dynamic Stability of an Exponentially Tapered Circular Revolving Beam Exposed to a Variable Temperature Grade under Several Boundary Arrangements

2019 ◽  
Vol 24 (3) ◽  
pp. 504-510
Author(s):  
Rakesh Ranjan Chand Chand ◽  
Pravat Kumar Behera ◽  
Madhusmita Pradhan ◽  
Pusparaj Dash
Keyword(s):  
Dynamic Stability ◽  
Variable Temperature ◽  
Research Work ◽  
Equation Of Motion ◽  
Revolution Speed ◽  
Static And Dynamic Stability ◽  
End Conditions ◽  
Variation Parameter ◽  
Instability Regions ◽  
The Stability

This research work is concerned with the static and dynamic stability study of an exponentially tapered revolving beam having a circular cross-section exposed to an axial live excitation and a variable temperature grade. The stability is analysed for clamped-clamped, clamped-pinned, and pinned-pinned end arrangements. Hamilton’s principle is used to develop the equation of motion and accompanying end conditions. Then, the non-dimensional form of the equation of motion and the end conditions are found. Galerkin’s process is used to find a number of Hill’s equations from the non-dimensional equations. The parametric instability regions are acquired by means of the Saito-Otomi conditions. The consequences of the variation parameter, revolution speed, temperature grade, and hub radius on the instability regions are examined for both static and dynamic load case and represented by a number of plots. The legitimacy of the results is tested by plotting different graphs between displacement and time using the Runge-Kutta fourth-order method. The results divulge that the stability is increased by increasing the revolution speed; however, an increase in the variation parameter leads to destabilization in the system and for same parameters, the stability is less in the case of a variable temperature grade than that of a constant temperature grade condition.

scholarly journals ДИНАМІЧНА РЕАКЦІЯ ТА СТІЙКІСТЬ ПОШКОДЖЕНОЇ КОНСТРУКЦІЇ ТРАНСПОРТНОГО ЛІТАКА

2020 ◽  
pp. 173-180
Author(s):  
Є. Ю. Іленко ◽  
В. М. Онищенко
Keyword(s):  
Dynamic Stability ◽  
Equations Of Motion ◽  
Initial Perturbation ◽  
Aerodynamic Characteristics ◽  
Operating Conditions ◽  
Ultimate State ◽  
Main Method ◽  
Operating Load ◽  
The Stability

In the process of designing and operating the aircraft, it is important to determine the ultimate state of the structure, taking into account the dynamic load of the structure and its stability. The ultimate state of the structure is characterized by damage, in which the structure still retains the ability to withstand without catastrophic destruction of the maximum operating load. The main method of studying the stability of the structure is the dynamic method. It allows us to investigate the perturbed motion of a structure as a nonconservative system for some initial perturbation. The monotonic departure of the system from the equilibrium position or its oscillations with increasing amplitudes indicate the instability of the structure. The paper analyzes the effect of damage to the aircraft structure on its dynamic stability based on the determination of the dynamic response of the aircraft to some non-stationary perturbation, for example, on the action of a turbulent atmosphere. The method of computational analysis is used to study the dynamic stability of the structure. The basis of this method is mathematical modeling (MM) of the operation of the aircraft in the form of a system of equations of motion and deformation of the structure. The problem of dynamic aeroelasticity is considered - the behavior of the elastic damaged structure of the aircraft in the air flow to the initial perturbation. On the basis of computer simulation, the dynamic stability of the elastic structure, its oscillating or quasi-static (aperiodic) deformation motion within the flight range of the aircraft is estimated. On the basis of parametric researches the limits of instability of a design at the set damages for typical operating conditions are estimated. The relevance of the direction focused on the creation and advanced operation of MM aircraft - their mathematical backups in the process of design and operation of aircraft due to the complexity and limited capabilities of ground experimental installations and flight experiment. It is noted that the condition for the application of this method is the formed MM operation of the aircraft and the availability of information on the mass-inertial, stiffness and aerodynamic characteristics of the aircraft.

scholarly journals STUDY ON THE STATIC AND DYNAMIC STABILITY OF A MODULAR AIRPLANE SYSTEM

Aviation ◽  
2016 ◽  
Vol 20 (4) ◽  
pp. 160-167 ◽  
Author(s):  
Agnieszka KWIEK
Keyword(s):  
Dynamic Stability ◽  
Static Stability ◽  
Space Technology ◽  
Space Flights ◽  
Space Tourism ◽  
Longitudinal Dynamic ◽  
Static And Dynamic Stability ◽  
Control Derivatives ◽  
Point To Point ◽  
The Stability

The purpose of this research is an analysis of the static and dynamic stability of the Modular Airplane System (MAS). The MAS is designed to perform suborbital space flights. The concept assumes that two tailless vehicles bonded together form a conventional aircraft where the wing of the second one is used as the horizontal tail of the whole system. The CFD calculations, and the stability and control derivatives were conducted by the PANUKL package, which uses a low order panel method for the aerodynamic analysis. The analysis of the static and dynamic stability was performed by the SDSA package. Only the selected part of the MAS mission was investigated. The results that will be presented have been divided into three parts: static stability, longitudinal dynamic stability and lateral dynamic stability. The MAS has a few possible applications. The first one is a suborbital space tourism flight. Moreover, it can be used as a lunching vehicle for micro satellites or as a testing platform for new space technology to improve their TRL level. Finally, in the far future, it could be used as a fast point-to-point travel system. The paper presents the results of the static and dynamic stability of a unique aircraft configuration which consists of two tailless vehicles. The research focuses on a situation where the vehicles are just before separation and their mass is similar. Moreover, the influence of the second vehicle’s position with respect to the first one is included.

Dynamic Stability of Disks With Periodically Varying Spin Rates Subjected to Stationary In-Plane Edge Loads

2004 ◽  
Vol 71 (4) ◽  
pp. 450-458 ◽  
Author(s):  
T. H. Young ◽  
M. Y. Wu
Keyword(s):  
Dynamic Stability ◽  
Multiple Scales ◽  
Equations Of Motion ◽  
Parametric Instability ◽  
Stress Distributions ◽  
The Finite Element Method ◽  
Nodal Diameter ◽  
The Stability ◽  
Small Periodic ◽  
Small Periodic Perturbation

This paper presents an analysis of dynamic stability of an annular plate with a periodically varying spin rate subjected to a stationary in-plane edge load. The spin rate of the plate is characterized as the sum of a constant speed and a small, periodic perturbation. Due to this periodically varying spin rate, the plate may bring about parametric instability. In this work, the initial stress distributions caused by the periodically varying spin rate and the in-plane edge load are analyzed first. The finite element method is applied then to yield the discretized equations of motion. Finally, the method of multiple scales is adopted to determine the stability boundaries of the system. Numerical results show that combination resonances take place only between modes of the same nodal diameter if the stationary in-plane edge load is absent. However, there are additional combination resonances between modes of different nodal diameters if the stationary in-plane edge load is present.

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