Results 41 to 50 of about 189,925 (269)

Research on Secondary Condensation Method Based on Substructure Method for Helicopter Tail Boom Model

Aerospace
The tail boom is a critical structural component of a helicopter, and accurately capturing its dynamic characteristics is essential; however, the inherent geometric and material complexity of the tail boom usually leads to large-scale finite element ...
Kunjian Jin, Xu Wang, Guoke Huang, Yingqi Zhang, Guorui Yu, Xiao Wang   +5 more
doaj   +1 more source

THE EFFECT OF DIFFERENT OPTIONS OF BLADES MAIN ROTOR ON THE X-SHAPED TAIL ROTOR OF THE MI-171 LL

Научный вестник МГТУ ГА, 2018
This paper describes the effect of different rotor blades on the X-shaped tail rotor of the Mi-171 LL, observed conducting flight tests. The tests were carried out on the same helicopter in the similar atmospheric conditions.The objective of the tests ...
V. A. Ivchin, V. A. Nikiforov, K. Yu. Samsonov   +2 more
doaj   +1 more source

Cordilleran Ice Sheet early deglaciation inferred from evolution of Late‐Pleistocene glacial Lake Dzulh Stun in east‐central British Columbia, Canada

Journal of Quaternary Science, EarlyView.
Abstract We document the early decay of the Late‐Pleistocene Cordilleran Ice Sheet in the central portion of the Rocky and Cariboo Mountains and the Rocky Mountain Trench in east‐central British Columbia. Glacial lakes impounded at the eastern margin of the ice sheet occupied watersheds on the west flank of the central Rocky Mountains, leaving ...
Brendan G. N. Miller, John J. Clague, Andrée Blais‐Stevens   +2 more
wiley   +1 more source

Helicopter Accident Survivability [PDF]

Journal of the Royal Army Medical Corps, 1984
Army Air Corps accident and fatality rates have now reached levels which compare favourably with data from other civilian and military sources. This improvement is the result of enhanced helicopter design and parallel progress in aircrew training. The introduction of new generations of turbine powered rotor craft has largely eliminated mechanical ...
P, Vyrnwy-Jones, R, Thornton
openaire   +2 more sources

Moose indifferent to canopy loss from forest disturbance by bark beetles

The Journal of Wildlife Management, EarlyView.
Moose showed strikingly similar patterns of habitat selection before and after widespread forest disturbance following an infestation of bark beetles. Our findings indicate that beetle‐kill does not appreciably alter habitat quality for moose and highlight the importance of riparian areas in sustaining moose as they contend with changing forests ...
Alexander B. May, Rebecca L. Levine, Lee Knox, Corey Class, Matthew J. Kauffman, Kevin L. Monteith   +5 more
wiley   +1 more source

Adaptive Feedforward Vibration Control of Helicopter Cabin Floor Driven by Piezoelectric Stack Actuators: Modeling, Simulation and Experiments

International Journal of Aerospace Engineering
Active control of structural response is the most practical and effective approach to mitigate helicopter vibration and enhance ride quality. In this paper, adaptive feedforward vibration control is constructed for the helicopter cabin floor driven by ...
Laishou Song, Yingquan Wang, Xiaoyu Shen
doaj   +1 more source

Applicability of the steady‐state oxygen stable isotope method for estimating metabolism in low‐productivity Arctic lakes

Limnology and Oceanography: Methods, EarlyView.
Abstract Metabolism is a key property of lake ecosystem functioning, but logistical challenges make it difficult to estimate across remote regions. The steady‐state dissolved oxygen (DO) stable isotope method (18O method) estimates metabolism from discrete water samples and thus enables large‐scale surveys.
Fredrik Alriksson, Marcus Klaus, Cristian Gudasz, Matthew Bogard, Gerard Rocher‐Ros, Dominic Vachon, Jan Karlsson   +6 more
wiley   +1 more source

Research on Whirl‑Flutter Characteristics of Distributed Propulsive Rotorcraft

Nanjing Hangkong Hangtian Daxue Xuebao
Aiming at the problem of whirl-flutter dynamics of distributed propulsion rotorcraft in high-speed forward flight state， this paper proposes a highly versatile， fast and efficient distributed multi-rotor/tilt-wing coupled aeroelastic dynamics analysis ...
CHENG Yi, YU Zhihao, WANG Siwen, ZHAO Jinrui   +3 more
doaj   +1 more source

Ellipsoid‐Based Interval‐Type Uncertainty Model Updating Based on Riemannian Manifold and Gaussian Process Model

International Journal of Mechanical System Dynamics, EarlyView.
ABSTRACT Modern engineering systems require advanced uncertainty‐aware model updating methods that address parameter correlations beyond conventional interval analysis. This paper proposes a novel framework integrating Riemannian manifold theory with Gaussian Process Regression (GPR) for systems governed by Symmetric Positive‐Definite (SPD) matrix ...
Yanhe Tao, Qintao Guo, Jin Zhou, Cheng Yi   +3 more
wiley   +1 more source

Design of Swarm Intelligence Control Based on Double-Layer Deep Reinforcement Learning

Applied Sciences
Traditional methods have limitations regarding efficient collaboration and dynamic response in complex dynamic environments. Although existing swarm intelligence control methods possess certain adaptive optimization capabilities, they still face ...
Xiangpei Yan, Guorui Yu, Guoke Huang, Ruchuan Zhou, Liu Hao   +4 more
doaj   +1 more source