Results 31 to 40 of about 314,370 (260)
Effect of axial spacing on rotating stall performance of FBCDZ-10-No20 contra-rotating fan
Meitan kexue jishu, 2023 Mining contra-rotating fan are prone to rotational stall when it operates at low flow rates, which seriously affects the operational stability. The unsteady flow in the full flow passage of a FBCDZ-10-No20 contra-rotating fan at five axial spacings was ...
Qingguang CHEN +3 more
doaj +1 more source
Main rotor-tail rotor intraction and its implications for helicopter directional control [PDF]
, 2008 Aerodynamic interference between the main and tail rotor can have a strong negative influence on the flight mechanics of a conventional helicopter. Significant unsteadiness in the tail rotor loading is encountered under certain flight conditions, but the
Fletcher, Timothy M., Brown, R.E.
core +4 more sources
Aerodynamics Optimization of a Ducted Coaxial Rotor in Forward Flight Using Orthogonal Test Design
Shock and Vibration, 2018 To investigate the aerodynamic complexities involved in the combination of freestream and propeller’s suction flow field of ducted coaxial rotors system in forward flight, an orthogonal L16(43) test design has been applied to optimize the design ...
Yuening Jiang, Hai Li, Hongguang Jia
doaj +1 more source
Optimization of the Guiding Stability of a Horizontal Axis HTS ZFC Radial Levitation Bearing
Actuators, 2021 This document presents a study on the optimization of the 3D geometry of a horizontal axis radial levitation bearing with zero-field cooled (ZFC) high-temperature superconductor (HTS) bulks in the stator, and radially magnetized permanent magnet (PM ...
António J. Arsénio +3 more
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Effects of rotor separation on the axial descent performance of dual-rotor configurations
Flow, 2023 Rotorcraft can encounter highly unsteady flow when descending at a steep angle, leading to a flow condition called vortex ring state, which is associated with strong oscillatory airloads and substantial losses in mean rotor thrust.
Marcel Veismann +2 more
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Diffusion resonances in action space for an atom optics kicked rotor with decoherence [PDF]
Physical Review E, 2002 We numerically investigate momentum diffusion rates for the pulse kicked rotor across the quantum to classical transition as the dynamics are made more macroscopic by increasing the total system action. For initial and late time rates we observe an enhanced diffusion peak which shifts and scales with changing kick strength, and we also observe ...
Daley, A. J. +3 more
openaire +3 more sources
Energies, 2023 To elucidate the wind-direction dependence of the rotor performance in closely spaced vertical-axis wind turbines, wind-tunnel experiments were performed at a uniform wind velocity.
Yoshifumi Jodai, Yutaka Hara
doaj +1 more source
Aerodynamic Optimization Design of an Orthogonal Octo-Rotor UAV in a Hovering State
DronesThis paper presents a novel orthogonal octo-rotor Unmanned Aerial Vehicle (UAV) and addresses the aerodynamics of the UAV with varied rotor spacing by both numerical simulations and experiments.
Yao Lei +5 more
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CFD-FEM Analysis of Flow-Induced Vibrations in Waterjet Propulsion Unit
Journal of Marine Science and Engineering, 2022 This paper investigates the problem of vibration in an axial flow waterjet propeller with high power density and low specific speed. Based on fluid–structure coupling vibration analysis, combined with modal analysis and ship tests, the unsteady fluid ...
Yuanxing Dai +4 more
doaj +1 more source
Frontiers in Energy ResearchIntroductionTandem dual-rotor wind turbines achieve efficient wind energy capture through aerodynamic coupling between upstream and downstream rotors.
Xinkai Li +8 more
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