Results 31 to 40 of about 7,858 (154)

Using unmanned aerial vehicles (drones) to improve access to blood in low‐ and middle‐income countries: Current challenges and opportunities

Vox Sanguinis, EarlyView.
Abstract Blood transfusion is life‐saving for patients in emergencies, but low‐ and middle‐income countries (LMICs) often face a severe shortage of banked blood. Establishing blood banks in rural areas presents substantial logistical and economic challenges for many LMICs.
Suvro Sankha Datta, Ritwick Mondal, Shramana Deb, Giuseppe Tortora, Angela Pirri   +4 more
wiley   +1 more source

Computational investigations of Ka-226T helicopter coaxial rotor aerodynamics in the vortex ring state

Научный вестник МГТУ ГА
The vortex ring states are observed when the rotor is flowed at positive angles of attack. For the main rotor, these conditions are realized during a steep descent of the helicopter at low speeds.
P. V. Makeev, Yu. M. Ignatkin, A. I. Shomov, S. V. Selemenev   +3 more
doaj   +1 more source

Empirical measurements of small unmanned aerial vehicle co-axial rotor systems [PDF]

, 2011
Small unmanned aerial vehicles (SUAV) are beginning to dominate the area of intelligence, surveillance, target acquisition and reconnaissance (ISTAR) in forward operating battlefield scenarios.
Bell, Jonathon, Prior, Stephen D.
core  

Design of HAWT Rotor for Non‐Uniform Inflow Conditions: A Theoretical and Experimental Approach for Shear Flow

Energy Science &Engineering, Volume 14, Issue 4, Page 1935-1951, April 2026.
This paper aims to provide a robust design approach for HAWTs operating in shear flow. This study fills a critical research gap by integrating BEM and vortex theories for blade design in non‐homogeneous inflow conditions. The authors of the paper made an effort to develop and test an experimentally unsophisticated model of a turbine working in shear ...
Agnieszka Dorota Woźniak, Piotr Strzelczyk, Taeseong Kim   +2 more
wiley   +1 more source

Effect of Bearing Support Parameters on the Radial and Angular Deformation of Rotor Shaft Gear Based on CRDRS Support Configuration with Intermediate Bearing Support

Machines
The rotor shaft is a critical component responsible for transmitting engine power to the helicopter’s rotor. Deformation of the rotor shaft can affect the meshing performance of the output stage gears in the main gearbox, thereby affecting load transfer ...
Xiaojie Yuan, Xiaoyu Che, Rupeng Zhu, Weifang Chen   +3 more
doaj   +1 more source

The Generating Mechanism and Suppression Measure of the ‘Wheel‐Rail’ Rolling Arc for Electrified Trains

High Voltage, Volume 11, Issue 2, Page 370-384, April 2026.
ABSTRACT As the ‘main blood vessel’ of the traction power supply system for high‐speed trains, the ‘wheel‐rail’ coupling grounding reflux system provides the vital channel to send traction current back to terrestrial substations; meanwhile, the rail track also plays a role in transmitting the train's occupancy signal to the control system. An insulated
Jiefu Hou, Song Xiao, Mengqiao Wang, Pupu Li, Guangning Wu, Ye Cao, Guoqiang Gao, Yujun Guo, Xueqin Zhang, Yongdong He   +9 more
wiley   +1 more source

Simulation of Unsteady Aerdynamic Load for Rigid Coaxial Rotor in Forward Flight with Vortex Particle Method [PDF]

, 2017
Co-axial rotor systems are frequently used for high-speed helicopters. Nevertheless, issues related to rotor-head drag, aerodynamic performance and vibration should also be considered. Simulating the unsteady aerodynamic loads for a rigid coaxial rotor,
Barakos, George N., Sun, Yiming, Tan, Jianfeng   +2 more
core  

The Future of Hydrogen‐Powered Aviation: Technologies, Challenges, and a Strategic Roadmap for Sustainable Decarbonization

Advanced Energy and Sustainability Research, Volume 7, Issue 3, March 2026.
Hydrogen‐powered aviation offers a transformative pathway to zero‐emission flight by eliminating in‐flight CO2 emissions. Key considerations include propulsion systems (fuel cells and hydrogen combustion), cryogenic storage and insulation challenges, infrastructure and cost barriers, and supply‐chain constraints.
Mubasshira, Md Mahbubur Rahman, Karib Hassan Khan, Md Nizam Uddin, Dewan Hafiz Nabil   +4 more
wiley   +1 more source

Aeroacoustics of a coaxial rotor in level flight [PDF]

, 2008
The aeroacoustic characteristics of a coaxial system with teetering rotors in level forward °ight are com- pared to those of an equivalent articulated single rotor with the same solidity.
Brown, R.E., Duraisamy, K., Kim, H.W.
core   +1 more source

Design Challenges to Expand the Functionality of Drones: Deformable Rotorcraft and Nature‐Inspired Flapping Drones

Advanced Intelligent Systems, Volume 8, Issue 3, March 2026.
This review systematically analyzes deformable drones, including extendable, foldable, and tilting configurations, along with nature‐inspired flapping rotorcraft. By classifying deformation principles and structural mechanisms, design trade‐offs, functional capabilities, and future development potential are highlighted.
Ju‐Hee Lee, Sumin Jung, Jinwoo Jang, Yeji Han, Minchae Kang, Jihun Seong, Suyeon Seo, Eunsol Park, Haesol Kwak, Min‐Woo Han   +9 more
wiley   +1 more source