Results 111 to 120 of about 66,325 (272)

Rotor blade design and dynamic characteristics analysis of unmanned helicopter

Hangkong gongcheng jinzhan
The widespread application of composite materials in blades also makes the force and stiffness characteristics of blades more complex than traditional blades.
GAO Hongbo
doaj   +1 more source

Effects of nonuniform swash-plate stiffness on coupled blade-control system dynamics and stability [PDF]

, 1972
Program has been developed that analytically determines effects of nonuniform swash-plate support stiffness, swash-plate flexibility, and out-of-blade track on vibratory mechanical stability characteristics of helicopter rotor systems.
Piarulli, V. J.
core   +1 more source

A method for tail rotor aerodynamic force prediction under rotor interference based on coupled momentum source and blade element theory

Xibei Gongye Daxue Xuebao
Due to the influence of slip flow and wake, the tail rotor of a helicopter may produce strong unsteady aerodynamic force in its main rotor interference flow field, which may affect the helicopter control and lead to structural failure.
WEN Long, ZHAO Xu, WANG Weite, LIU Xinyuan, YU Haiyang, HE Long, HE Shun   +6 more
doaj   +1 more source

Reduction of high-speed impulsive noise by blade planform modification of a model helicopter rotor [PDF]

The reduction of high speed impulsive noise for the UH-1H helicopter was investigated by using an advanced main rotor system. The advanced rotor system had a tapered blade planform compared with the rectangular planform of the standard rotor system ...
Conner, D. A., Hoad, D. R.
core   +1 more source

The effect of helicopter configuration on the fluid dynamics of brownout [PDF]

, 2008
Brown’s Vorticity Transport Model, coupled to an additional particle transport model, is used to simulate the development of the dust cloud that can form around a helicopter when operating in dusty or desert conditions.
Brown, R., Phillips, C.
core   +1 more source

Results of the flight noise measurement program using a standard and modified SH-3A helicopter [PDF]

A field noise measurement program has been conducted using both a standard SH-3A helicopter and an SH-3A helicopter modified to reduce external noise levels.
Henderson, H. R., Hilton, D. A., Pegg, R. J.   +2 more
core   +1 more source

High Lift, Low Pitching Moment Airfoils [PDF]

, 1988
Two families of airfoil sections which can be used for helicopter/rotorcraft rotor blades or aircraft propellers of a particular shape are prepared. An airfoil of either family is one which could be produced by the combination of a camber line and a ...
Noonan, Kevin W.
core   +1 more source

Investigation of Helicopter Blade Tip Configuration during Hover Flight Employing Computational Fluid Dynamics

Modelling and Simulation in Engineering
Our research focused on investigating the influence of rotor blade tip geometry on the aerodynamic performance of helicopters during hover flight, with the goal of enhancing overall efficiency.
Soufiane Stouti, Assel Thami Lahlou, Ismail Lagrat, Hamid Mounir, Oussama Bouazaoui   +4 more
doaj   +1 more source

Vibratory Loads Data from a Wind-Tunnel Test of Structurally Tailored Model Helicopter Rotors [PDF]

An experimental study was conducted in the Langley Transonic Dynamics Tunnel to investigate the use of a Bell Helicopter Textron (BHT) rotor structural tailoring concept, known as rotor nodalization, in conjunction with advanced blade aerodynamics as ...
Hamouda, M-Nabil H., Idol, Robert F., Mirick, Paul H., Singleton, Jeffrey D., Wilbur, Matthew L., Yeager, William T., Jr.   +5 more
core   +1 more source

PASSIVE CONTROL OF SHOCK WAVE APPLIED TO HELICOPTER ROTOR HIGH-SPEED IMPULSIVE NOISE REDUCTION

TASK Quarterly, 2010
A strong, normal shock wave, terminating a local supersonic area on an airfoil (or a helicopter blade), not only limits the aerodynamic performance, but also becomes a source of High-Speed Impulsive (HSI) noise.
PIOTR DOERFFER, OSKAR SZULC
doaj