Geometric Nonlinear Controllability Analysis for Airplane Flight Dynamics

Generalized geometric nonlinear damping based on the viscous damper with a non-negative velocity exponent is proposed to improve the isolation performance of a quasi-zero stiffness (QZS) vibration isolator in this paper. Firstly, the generalized geometric nonlinear damping characteristic is derived. Then, the amplitude-frequency responses of the QZS vibration isolator under force and base excitations are obtained, respectively, using the averaging method. Parametric analysis of the force and displacement transmissibility is conducted subsequently. At last, two phenomena are explained from the viewpoint of the equivalent damping ratio. The results show that decreasing the velocity exponent of the horizontal damper is beneficial to reduce the force transmissibility in the resonant region. For the case of base excitation, it is beneficial to select a smaller velocity exponent only when the nonlinear damping ratio is relatively large.

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Two-parameter bifurcation analysis of longitudinal flight dynamics

IEEE Transactions on Aerospace and Electronic Systems ◽

10.1109/taes.2003.1238764 ◽

2003 ◽

Vol 39 (3) ◽

pp. 1103-1112 ◽

Cited By ~ 8

Author(s):

Der-Cherng Liaw ◽

Chau-Chung Song ◽

Yew-Wen Liang ◽

Wen-Ching Chung

Keyword(s):

Bifurcation Analysis ◽

Flight Dynamics ◽

Two Parameter ◽

Parameter Bifurcation

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Modeling and Analysis of a Generic Internal Cargo Airdrop System for a Tandem Helicopter

Applied Sciences ◽

10.3390/app11115109 ◽

2021 ◽

Vol 11 (11) ◽

pp. 5109

Author(s):

Guozhi Li ◽

Yihua Cao ◽

Maosheng Wang

Keyword(s):

Nonlinear Dynamics ◽

Flight Dynamics ◽

Simulation Method ◽

Rotational Dynamics ◽

Discretization Method ◽

Modeling And Analysis ◽

Flight Velocity ◽

Vector Mechanics ◽

Good Attitude

This article describes the results of modeling and analysis of a generic internal cargo system using a discretization method of the vector mechanics. The model can be easily incorporated into a tandem helicopter model and is intended for use of simulation and investigating the problems of flight dynamics, control, etc., both in flight operation loading a cargo and flight operation in the process of airdrops. The model is derived by considering the main descriptions of the cargo, including the linear and rotational dynamics, the kinematics, and the forces and moments acting on the helicopter. A simulation method embedded with a numerical trim algorithm is developed for the complete coupling helicopter/cargo nonlinear dynamics system. The simulation application of the model is illustrated, including the case of flight operation loading a cargo by considering three mass configurations of 3000, 4500, and 6000 kg, and the case of flight operation in the process of airdrops at velocities of 0, 40, 80, 120, and 160 knots. Stabilities of the helicopter in the process of airdrops are also analyzed. The major conclusions drawn are: (i) the tandem helicopter has a good attitude maintaining ability in the whole flight velocity envelope when it conducts a flight operation loading a cargo; (ii) in the process of airdrops, the increase in flight velocity will constantly decrease the helicopter pitching attitude and increases the total airdrop time and decreases the backward moving velocity of the cargo, and helicopter flying at a velocity between 80 and 120 knots might be acceptable; (iii) the stabilities of both the longitudinal and lateral periodic modes are continuing to decrease during the backward movement of the cargo.

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Flight Dynamics of Transport Aircraft Equipped with Flared-Hinge Folding Wingtips

Journal of Aircraft ◽

10.2514/1.c035940 ◽

2020 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Rafic M. Ajaj

Keyword(s):

Flight Dynamics ◽

Transport Aircraft

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