Results 261 to 270 of about 232,137 (308)

The motion reliability simulation and analysis of main rotor head of helicopter rotor system

2009 8th International Conference on Reliability, Maintainability and Safety, 2009
The motion of main rotor head of helicopter rotor system is complex. Its reliability influences flying qualities and safety of helicopter directly. But, traditional experiments and deterministic simulation have been difficult to measure movement (flapping, lead-laging and pitching angles) and analyze motion reliability of main rotor head quantitatively.
Fang Chen, Jianguo Zhang, Qi Gong, Yonglei Song, Duo Su   +4 more
openaire   +1 more source

Prediction of Main Rotor, Tail Rotor and Engine Parameters from Flight Tests

49th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference <br> 16th AIAA/ASME/AHS Adaptive Structures Conference<br> 10t, 2008
In the framework of this research project, the main rotor torque, tail rotor torque, engine torque and main rotor speed of a helicopter in forward flight are estimated by using a state space model from flight tests data. The state space model inputs are nonlinear terms made of combinations of pilot controls and helicopter states.
Michel Nadeau Beaulieu, Ruxandra Botez
openaire   +1 more source

Parametric structure optimization of a main rotor blade as an application for FSI analysis in main rotor optimization process

Aircraft Engineering and Aerospace Technology
Purpose Modern warfare and modern battlefield are very demanding. The recent conflicts showed that the usage of the helicopters is very limited and only the best constructions are able to provide support for the operations. The purpose of this research is to show the possibilities of new design tool for main rotor aerostructural optimization.
Jakub Kocjan, Robert Rogólski
openaire   +1 more source

Expendable Main Rotor Blade Study

1973
Abstract : The report presents results of a design study of expendable main rotor blades for the UH-1H helicopter. The objective of the study was to design blades which could eventually be thrown away after extensive damage rather than be sent back to depot for major overhaul. Unit cost, field repairability, resistance to corrosion and erosion, fatigue
Everett Fournier, John A. Longobardi
openaire   +1 more source

Vibrations of a Helicopter Rotor-Fuselage System Induced by the Main Rotor Blades in Flight

Journal of Applied Mechanics, 1955
Abstract Based on a simplified model of the hub-fuselage structure, a theoretical analysis is made of the response of the hub and fuselage of a helicopter in flight to harmonic forces transmitted by the rotor blades to the hub both in, and normal to, the plane of rotation.
M. Morduchow, S. W. Yuan, H. Reissner
openaire   +1 more source

The Effect of Helicopter Main Rotor Blade Damage on the Rotor Disk (Whole Rotor) Motion

2000
Abstract : When a helicopter main rotor blade is ballistically damaged, an imbalance is created in the rotor, causing the rotor disk to execute unwanted motions, which are detrimental to performance. The normally smooth-flying helicopter develops new vibrations that can be physiologically annoying or debilitating to the pilot, can exceed structural ...
openaire   +1 more source

Failure Analysis of a Helicopter's Main Rotor Bearing

Key Engineering Materials, 2012
Presented results report some of the findings of a detailed failure analysis carried out on a main rotor hub assembly, which had symptoms of burning and mechanical damage. The analysis suggests environmental degradation of the grease which causes pitting on bearing-balls.
M. Shahzad, A.H. Qureshi, H. Waqas, N. Hussain, L. Ali   +4 more
openaire   +1 more source

Agility Assessment of Helicopter Main Rotor Design

Proceedings of the Vertical Flight Society 75th Annual Forum, 2019
A methodology to implement agility as a tradeoff parameter into multi-disciplinary optimization of a helicopter rotor is proposed. Being a qualitative evaluation measure and having no clear definition, agility is tried to be quantified through utilization of "ease", "speed" and "precision" metrics.
Arda Yucekayali, Murat Senipek, Yuksel Ortakaya   +2 more
openaire   +1 more source

Disk wing to main rotor conversion mechanics

Russian Aeronautics (Iz VUZ), 2016
A mathematical model of spatial motion of the disk wing blades converted to the main rotor is presented. The system linkage parameters are defined.
V. V. Pavlov, M. S. Gasilov
openaire   +1 more source

Method for the Extraction of Helicopter Main and Tail Rotor Noise

Journal of Aircraft, 2018
In this paper a method for the extraction of main and tail rotor noise from an acoustic pressure time history of a helicopter is described.
openaire   +2 more sources