Results 91 to 100 of about 64,082 (287)

Rotor performance characteristics from an aeroacoustic helicopter wind-tunnel test program [PDF]

open access: yes
An investigation of helicopter rotor noise at model scale was conducted in the Langley 4 by 7 meter tunnel. The program described was the first of a planned three-phase project whose purpose was to examine the characteristic noise mechanism involved in ...
Elliott, J. W., Hoad, D. R., Orie, N. M.
core   +1 more source

Ground‐based robotic remote sensing for standardized biodiversity monitoring in coastal habitats

open access: yesRemote Sensing in Ecology and Conservation, EarlyView.
Illustrated workflow of the proposed citizen‐to‐robot monitoring pipeline: (i) expert‐validated citizen observations are translated into AI models, (ii) deployed on a ground‐based robotic platform for proximal sensing of coastal dune habitats, (iii) enabling standardized detection of ecological targets (e.g., Pancratium maritimum & Brithys crini), and (
Giovanni Di Lorenzo   +5 more
wiley   +1 more source

Control Law Design for Twin Rotor MIMO System with Nonlinear Control Strategy

open access: yesDiscrete Dynamics in Nature and Society, 2016
Modeling of complex air vehicles is a challenging task due to high nonlinear behavior and significant coupling effect between rotors. Twin rotor multi-input multioutput system (TRMS) is a laboratory setup designed for control experiments, which resembles
M. Ilyas   +5 more
doaj   +1 more source

An investigation of rotor harmonic noise by the use of small scale wind tunnel models [PDF]

open access: yes
Noise measurements of small scale helicopter rotor models were compared with noise measurements of full scale helicopters to determine what information about the full scale helicopters could be derived from noise measurements of small scale helicopter ...
Schaffer, E. G., Sternfeld, H., Jr.
core   +1 more source

Ionogel Actuators: A Review

open access: yesSmartBot, EarlyView.
Ionogels dynamically and functionally couple ionic liquids with polymer networks, enabling multiscale programmable deformation and motion under electrical, magnetic, optical, thermal, humidity, and chemical stimuli. This article systematically elucidates the constituent components, structural design, and multiscale actuation mechanisms of ionogel ...
Dezhou Cao   +5 more
wiley   +1 more source

Measurement method for repetition frequencies of the blades of an aerial vehicle on the base of the convolution of the «secondary» modulation spectrum

open access: yesДоклады Белорусского государственного университета информатики и радиоэлектроники, 2019
A novel measurement method for repetition frequencies of the blades of an aerial vehicle (in part, helicopter's main and tail rotor) for adaptation circuits of the radar sensor with an inverse synthesis of antenna aperture is proposed.
S. R. Heister, T. T. Nguyen
doaj  

Rating helicopter noise [PDF]

open access: yes
The effectiveness of the EPNL procedure in quantifying helicopter blade slap and tail rotor noise heard on approach some distance from the flyover position is addressed.
Leverton, J. W.   +2 more
core   +1 more source

Interactional aerodynamics and acoustics of a propeller-augmented compound coaxial helicopter [PDF]

open access: yes, 2008
The aerodynamic and acoustic characteristics of a generic hingeless coaxial helicopter with a tail-mounted propulsor and stabiliser have been simulated using Brown's Vorticity Transport Model.
Brown, Richard   +3 more
core  

Efficient Harvesting of Irregular and Low‐Frequency Mechanical Energy via Hybridized Electromagnetic‐Triboelectric Systems

open access: yesSmall, EarlyView.
ABSTRACT The rapid expansion of the Internet of Things (IoT) and wearable electronics necessitates sustainable power sources to replace the limited electrochemical battery. While mechanical energy harvesting offers a promising solution, traditional harvesters face challenges of irregular and low−frequency environmental sources. This review presents the
Yongbin Han   +2 more
wiley   +1 more source

RESULTS OF THE FIRST MI-171A2 FLYING LABORATORY TEST PHASE

open access: yesНаучный вестник МГТУ ГА, 2016
The present publication describes the results of the first stage of the flying laboratory (Mi-171 helicopter) flight tests performed at Mil Moscow Helicopter Plant, JSC facilities. Main rotor components with blades made of polymer composite materials and
V. A. Ivchin, K. Y. Samsonov
doaj  

Home - About - Disclaimer - Privacy