Results 21 to 30 of about 3,950 (148)

Thrust Characteristics of a Ducted Fan of a Quadcopter in Various Flight Modes

Fluids
Ducted fans are widely used in vehicles with a high engine power per unit swept area, including hovercraft propulsors and vertical take-off aircraft. Computational fluid dynamics (CFD) is a powerful tool for selecting the aerodynamic configuration of new
Pavel Bulat, Pavel Chernyshov
doaj   +1 more source

Development of a project to create a road transport infrastructure using small unmanned aircraft [PDF]

E3S Web of Conferences
The infrastructure for small unmanned aircraft has not yet been formed: there are no organized ground-based stations, there are no clear operating regulations for performing specialized types of work.
Duganova Elena, Novikov Ivan, Miroshnikov Evgeny, Dolzhenko Alexander   +3 more
doaj   +1 more source

Collision‐Resilient Winged Drones Enabled by Tensegrity Structures

Advanced Robotics Research, EarlyView.
Based on structures of birds such as the woodpeck, this article presents the collision‐resilient aerial robot, SWIFT. SWIFT leverages tensegrity structures in the fuselage and wings which allow it to undergo large deformations in a crash, without sustaining damage. Experiments show that SWIFT can reduce impact forces by 70% over conventional structures.
Omar Aloui, Raphael Zufferey, William Stewart, Mohammad Askari, Simon Jeger, Dario Floreano   +5 more
wiley   +1 more source

Chance-constrained optimal power flow for improving line flow and voltage security of power transmission networks

Autonomous Intelligent Systems
With the growing penetration of renewable energy, the impact of renewable uncertainties on power system secure operation is of increasing concern. Based on a recently developed linear power flow model, we formulate a chance-constrained optimal power flow
Yaodan Cui, Yue Song, Kairui Feng, Haonan Xu, Qinyu Wei, Kaiyu Li   +5 more
doaj   +1 more source

A Global Methane Observation System to Reduce Uncertainty for Anthropogenic and Natural Sources and Sinks for Detecting and Attributing Climate Feedbacks

Advanced Science, EarlyView.
Conceptual illustration of a Global Ecosystem Methane Observing System (GEM‐OS) integrating satellites, aircraft, atmospheric networks, and ecosystem measurements to quantify methane emissions from anthropogenic and natural sources. The multi‐scale observing framework improves source attribution, reduces uncertainty in regional methane budgets, and ...
P. Ciais, S. Peng, J. Chang, F. Li, Q. Zhu, K. Yuan, G. Hugelius, H. Li, Y. Cai, F. Chevallier, K. Tibrewal, E. A. Kort, K. Arndt, J. Watts, B. Buma, N. Besic, P. I. Palmer, H. Cadillo‐Quiroz, E. Euskirchen, M. J. Gondwe, A. Hoyt, R. Jackson, S. Malone, D. Monteverde, S. Natali, M. Ramonet, C. Rey‐Sanchez, L. B. Sagang, E. A. G. Schuur, R. Vargas, R. Varner, Z. Zhang, B. Poulter   +32 more
wiley   +1 more source

UAS Maintenance: A Critical Component in Maintaining Airworthiness

International Journal of Aviation, Aeronautics, and Aerospace, 2018
Over the last several decades, the notion of traditional aircraft design has significantly changed. While there are many modern aircraft that resemble earlier models, their components, systems, and overall architecture have evolved, including the ...
Bettina M Mrusek, Kristy W Kiernan, Patti J. Clark   +2 more
doaj   +1 more source

Topology‐Enabled Finite‐Band Absorption Framework Based on a Bioinspired Nested Dual‐Loop Architecture

Advanced Science, EarlyView.
A nuclear‐pore‐inspired nested dual‐loop architecture redistributes electromagnetic energy through coupled transport, confinement, and dissipation pathways. Integrated with Co/Fe3O4 dual‐magnetic composites and topology optimization, the 11‐mm‐thick absorber delivers continuous 2–40 GHz attenuation, raises finite‐band structural utilization to 82%, and
Shaokang Liu, Weicheng Liao, Pinchen Luo, Mengchen Jin, Tangming Yan, Xing Zhao, Qingshan Wang   +6 more
wiley   +1 more source

A Review of Detect and Avoid Standards for Unmanned Aircraft Systems

Aerospace
When operating an unmanned aircraft system within the specific category beyond Air Risk Class a or within the certified category, a detect and avoid system is required in order to mitigate the risk of colliding with manned aircraft.
Marcel Riedel
doaj   +1 more source

The use of Unmanned Aircraft Systems (UAS) in combat operations [PDF]

Transport Problems, 2011
In this publication has been presented selected aspects of the wide spectrum of Unmanned Aircraft Systems (UAS)/UAV adaptation within the military structures.
Tomasz GUGAŁA
doaj  

Cross‐scale Material‐Structure Synergy for 2D Metamaterials: Toward Customizable Intelligent Electromagnetic Manipulation in Multiphysics Fields

Advanced Science, EarlyView.
Recent advances in metasurface‐enabled low‐observable technologies are reviewed from the perspective of cross‐scale material–structure synergy. Electromagnetic, thermal, optical, and acoustic stealth are highlighted together with dynamic tuning, programmable coding, data‐driven inverse design, artificial intelligence, multispectral compatibility, and ...
Shuhao Wang, Xing Yang, Liping Liu, Yang Peng, Yangyang Wang, Hualiang Lv   +5 more
wiley   +1 more source