Results 211 to 220 of about 54,340 (264)

Helicopter Main-Rotor/Tail-Rotor Interaction

Journal of the American Helicopter Society, 2000
Preliminary results from a study to model the interaction aerodynamics and aeroacoustics of the main and tail rotor of a helicopter in subsonic flow are presented. The configurations studied are: 1) two bladed main and tail rotors in hover, and 2) a four-bladed main rotor and two-bladed tail rotor in climbing flight.
Yin, J., Ahmed, S.R.
openaire   +3 more sources

Aerodynamics and aeroacoustics of helicopter main-rotor/tail-rotor interaction

5th AIAA/CEAS Aeroacoustics Conference and Exhibit, 1999
Preliminary results from an ongoing effort to model the interaction aerodynamics and aeroacoustics of main- and tail rotor of a helicopter in subsonic flow are presented. The configurations studied are a) a two-blade main- and tail rotor in hover, and b) a four-blade main- and a two-blade tail rotor in climb flight.
Ahmed, S.R., Yin, J.
openaire   +2 more sources

Tri-quadrotor with main and secondary rotor

2020 Chinese Automation Congress (CAC), 2020
Multi-rotor aircrafts were widely used in military and civilian fields. However, the development of multirotor aircraft was limited by power and endurance time. In order to improve these problems, this paper focused on the flight module with one main rotor and three secondary rotors under the triangular frame, which can form the Unmanned Aerial Vehicle
Wei Dong, Qi Gao, Feng Pan
openaire   +1 more source

Modelling the interaction of helicopter main rotor and tail rotor wakes

The Aeronautical Journal, 2007
AbstractThe mutual interaction between the main rotor and tail rotor wakes is central to some of the most problematic dynamic phenomena experienced by helicopters. Yet achieving the ability to model the growth and propagation of helicopter rotor wakes with sufficient realism to capture the details of this interaction has been a significant challenge to
T. M. Fletcher, R. E. Brown
openaire   +1 more source

Main Rotor Yoke Cracking

1992
Abstract The 4340 steel main rotor yoke of a helicopter failed during a hovering exercise. Visual examination of the yoke revealed no evidence of gross external damage. Visual fracture surface examination, macrofractography, scanning electron micrography, and metallography of a section cut from the yoke in the region of the cracking ...
S.R. Lamb, G. Clerk
openaire   +1 more source

Titanium UTTAS Main Rotor Blade

Journal of the American Helicopter Society, 1976
A description of the design philosophy leading to the development of a high performance rotor blade for the Army UTTAS helicopter is presented. The Army mission requirements of 550 fpm rate‐of‐climb at 4000 ft, 95° conditions and a 1.75 g maneuver at 150 knots translate into Figure of Merit and aeroelastic achievements beyond those of existing rotors.
Peter Arcidiacono, Robert Zincone
openaire   +1 more source

Lynx Main Rotor/Tail Rotor Interactions: Mechanisms and Modelling

Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 1994
A flight trial has been conducted by the Defence Research Agency (DRA) Bedford using a Lynx AH Mk5 helicopter fitted with an instrumented tail rotor to collect data on tail rotor aerodynamic performance. The analysis carried out to date has concentrated on the effects of main rotor wake interactions on the tail rotor. This paper describes the trial and
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

Kinematic and Dynamic Modeling of a Helicopter Rigid Main Rotor

Volume 2: 32nd Mechanisms and Robotics Conference, Parts A and B, 2008
Analysis of the kinematics and dynamics of a helicopter main rotor is presented in the paper. A rigid rotor type is assumed, where feathering angle of the blade is controlled by a swashplate mechanism. Kinematic constrains and links equilibrium are studied in order to determine the mechanism movement and the forces on the servoactuators which drive the
BATTEZZATO, ALESSANDRO, PASTORELLI, STEFANO PAOLO, SORLI, Massimo   +2 more
openaire   +3 more sources

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