Helicopter Flight Dynamics Simulation with Continues-Time Unsteady Vortex Lattice-Free Wake and Multibody Dynamics

This paper presents the flight dynamics simulation and analysis of a tilt-rotor vertical takeoff and landing (VTOL) aircraft on transition phase, that is conversion from vertical or hover to horizontal or level flight and vice versa. The model of the aircraft is derived from simplified equations of motion comprising the forces and moments working on the aircraft in the airplane's longitudinal plane of motion. This study focuses on the problem of the airplane's dynamic response during conversion phase, which gives an understanding about the flight characteristics of the vehicle. The understanding about the flight dynamics characteristics is important for the control system design phase. Some simulation results are given to provide better visualization about the behaviour of the tilt-rotor. The simulation results show that both transition phases are quite stable, although an improved stability can give better manoeuver and attitude handling. Improvement on the simulation model is also required to provide more accurate and realistic dynamic response of the vehicle.

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Event-based scenario manager for multibody dynamics simulation of heavy load lifting operations in shipyards

International Journal of Naval Architecture and Ocean Engineering ◽

10.1016/j.ijnaoe.2015.10.004 ◽

2016 ◽

Vol 8 (1) ◽

pp. 83-101 ◽

Cited By ~ 1

Author(s):

Sol Ha ◽

Namkug Ku ◽

Myung-Il Roh

Keyword(s):

Multibody Dynamics ◽

Dynamics Simulation ◽

Heavy Load ◽

Event Based

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Helicopter Rotor Blade Flexibility Simulation for Aeroelasticity and Flight Dynamics Applications

Journal of the American Helicopter Society ◽

10.4050/jahs.59.042006 ◽

2014 ◽

Vol 59 (4) ◽

pp. 1-18 ◽

Cited By ~ 8

Author(s):

Ioannis Goulos ◽

Vassilios Pachidis ◽

Pericles Pilidis

Keyword(s):

Real Time ◽

Rotor Blade ◽

Flight Dynamics ◽

Integrated Approach ◽

Flight Simulation ◽

Response Characteristics ◽

Helicopter Flight ◽

Finite State ◽

The Time Domain ◽

Blade Loads

This paper presents a mathematical model for the simulation of rotor blade flexibility in real-time helicopter flight dynamics applications that also employs sufficient modeling fidelity for prediction of structural blade loads. A matrix/vector-based formulation is developed for the treatment of elastic blade kinematics in the time domain. A novel, second-order-accurate, finite-difference scheme is employed for the approximation of the blade motion derivatives. The proposed method is coupled with a finite-state induced-flow model, a dynamic wake distortion model, and an unsteady blade element aerodynamics model. The integrated approach is deployed to investigate trim controls, stability and control derivatives, nonlinear control response characteristics, and structural blade loads for a hingeless rotor helicopter. It is shown that the developed methodology exhibits modeling accuracy comparable to that of non-real-time comprehensive rotorcraft codes. The proposed method is suitable for real-time flight simulation, with sufficient fidelity for simultaneous prediction of oscillatory blade loads.

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