Results 41 to 50 of about 416,529 (192)

Control of Aerodynamic Characteristics of Thick Airfoils at Low Reynolds Numbers Using Methods of Boundary Layer Control

Fluids
The article explores flow behavior around thick airfoils at low Reynolds numbers and the potential application of energy methods to manipulate the flow field for increased lift and reduced drag. The study relies on a set of propulsion airfoils calculated
Pavel Bulat, Pavel Chernyshov, Nikolay Prodan, Konstantin Volkov   +3 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

Classification and Diagnosis of Propeller Damages Using FFT-Based Motor Current Signature Analysis of DC-Link Current

IEEE Access
This study proposes a frequency-domain diagnostic approach for detecting and characterizing unmanned aerial vehicle (UAV) propeller damage using only motor electrical signals. Motor current signals were analyzed via fast Fourier transform (FFT) across 36
Giho Lee, Sewoong Park, Seungmin Choi, Sanga Lee, Jinseok Jeong, Donguk Lee   +5 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

Terminal airspace modelling for unmanned aircraft systems integration [PDF]

, 2016
This paper considers the problem of integrating unmanned aircraft into low altitude airspace above urban environments, including major terminal areas and helicopter landing sites.
Mcfadyen, Aaron, Aaron McFadyen, Terry Martin, Martin, Terry   +3 more
core   +1 more source

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

Finite element analysis of thermoplastic composite wing leading-edge structure for a modular unmanned aerial vehicle

Discover Applied Sciences
This study investigates the structural performance of a polyaryletherketone (PAEK)-based thermoplastic composite wing leading-edge design for the ASNLQ-218 unmanned aerial vehicle (UAV).
Feng Yang, Shanshan Tang, Daliang He, Heye Xiao, Zhiwei Sun, Yuelai Ding   +5 more
doaj   +1 more source

Smoke Diffusion Characteristics for Smoke Generator Based on Turbojet

Nanjing Hangkong Hangtian Daxue Xuebao
Based on the discrete phase model in the simulation software FLUENT， the smoke diffusion characteristics under high-speed jet action of a smoke generator powered by a turbojet engine are calculated.
CAO Guangzhou, REN Rui, SUN Hongliang
doaj   +1 more source

Overview of regulatory frameworks for unmanned aircraft [PDF]

Tehnika
This paper presents the regulatory framework for the use of unmanned aircraft in the airspace of the Republic of Serbia. The work contains an overview of regulations at the international level, primarily the regulations of the International Civil ...
Marina Miloš S., Mirosavljević Petar D.   +1 more
doaj   +1 more source

Drones or uncrewed aircraft – acronyms, definitions, and gender equality

Bulletin of "Carol I" National Defense University, 2023
Unmanned aircraft/drones are increasingly present in everyday life, from flight demonstrations, event filming, mapping, and agricultural use to delivering goods or, in the future, transporting people.
Cătălin BALMUȘ, Ph.D Candidate
doaj   +1 more source