Results 111 to 120 of about 605,830 (356)

Friction power loss in ball bearings: Correlation with bearing skidding and cage motion stability

Friction
This study introduces a prediction method for bearing friction power loss, focusing on the interplay of bearing skidding and cage motion stability on the tribological properties of ball bearings.
Mingkai Wang, Linbo Zhu, Kim Tiow Ooi, Haizhen Li, Ke Yan, Jun Hong   +5 more
doaj   +1 more source

Coupled thrust and vorticity dynamics during VRS [PDF]

, 2008
The focus is on the vortex ring state (VRS) observed at rapid descent rates. At VRS, the helical vortex filaments coming off the blades amalgamate around the rotor disk forming a vortex ring, which periodically detaches into the wake, causing extreme ...
Caradonna, F.X., Green, R.B., Savas, O.
core  

TreeSpider: In‐Canopy Exploration With Tether‐Based Aerial Modular Arms

Advanced Robotics Research, EarlyView.
A tethered drone with perching arms and a 360° ring enables unprecedented maneuverability within dense forest canopies. By dynamically adjusting tether length and decoupling pitch from the frame, it navigates between branches, senses multiple trees, and interacts physically with foliage.
Luca Romanello, Tian Lan, Salaheldin Hassan, Maximilian Leutschafft, Erdem Ekinci, Sophie F. Armanini, Mirko Kovac, Basaran Bahadir Kocer   +7 more
wiley   +1 more source

Impeller-Induced Rotor-Dynamic Forces [PDF]

, 1989
The flow through and around the rotor of a turbomachine exerts a force on the rotor and, hence, rotor shaft and bearing system. In some circumstances this force may lead to excitation of shaft whirl in the direction of impeller rotation.
Acosta, Allan J., Brennen, Christopher E., Caughey, Thomas K.   +2 more
core  

Degradable Magnetic Composites from Recycled NdFeB Magnets for Soft Actuation and Sensing

Advanced Robotics Research, EarlyView.
This work presents a degradable soft magnetic composite made from recycled NdFeB particles embedded in a gelatin‐based organogel. The material is processed into magnetic sensors and soft robotic components, which can later be dissolved in a green solvent to recover NdFeB magnetic particles.
Muhammad Bilal Khan, Lin Guo, Kilian Schäfer, Eduardo Sergio Oliveros‐Mata, Xiaotao Wang, Florian Hofmann, Matthias Lutzi, Mark Suppelt, Proloy Taran Das, Jan Schmidtpeter, Imants Dirba, Stephan Rinderknecht, Mario Kupnik, Denys Makarov, Oliver Gutfleisch   +14 more
wiley   +1 more source

Rotor performance characteristics from an aeroacoustic helicopter wind-tunnel test program [PDF]

An investigation of helicopter rotor noise at model scale was conducted in the Langley 4 by 7 meter tunnel. The program described was the first of a planned three-phase project whose purpose was to examine the characteristic noise mechanism involved in ...
Elliott, J. W., Hoad, D. R., Orie, N. M.
core   +1 more source

Waveguide Photoactuators: Materials, Fabrication, and Applications

Advanced Robotics Research, EarlyView.
Waveguide photoactuators convert guided light into mechanical motion. Their tethered‐flexible design enables minimally invasive surgery and confined‐space robotics. This review aims to guide materials selection, device design, and system integration, accelerating the transition of waveguide photoactuators from laboratory prototypes to versatile ...
Minjie Xi, Hemin Pan, Yang Zong, Yongfeng Mei, Jizhai Cui   +4 more
wiley   +1 more source

Case study of natural convection topology optimization based on finite volume method

Case Studies in Thermal Engineering
Topology optimization is crucial for improving natural convection cooling devices. This study applies natural convection topology optimization to various engineering cases, including 2D, 3D, inclined, and inverted heat sink with various boundary ...
Honglei Liu, Shuzhe Guo, Ce Liu, Fei Du, Baotong Li, Jun Hong   +5 more
doaj   +1 more source

Characteristic Analysis and Simulated Test of Hybrid Bearing with the Introduction of Piezoelectric Controller

Shock and Vibration, 2016
A novel hybrid bearing with the introduction of piezoelectric controller and tilting pads to control vibration actively is proposed in this paper, and the feasibility of this scheme is verified by theoretical calculation and experimental data.
Runlin Chen, Wu Ouyang, Zhaoyang Shi, Yangyang Wei, Xiaoyang Yuan   +4 more
doaj   +1 more source

Sleep Alters the Velocity of Physiological Brain Pulsations in Humans

Advanced Science, EarlyView.
Sleep alters I/CSF oscillatory flow, driven by increased respiratory (29%) and vasomotor pulsation (21%) velocities, while cardiovascular pulsations decreased by (22%). Velocity is quantified using optical flow analysis of MREG data. Spectral power increases alongside these pulsations (spatial correlation, r = 0.35 and r = 0.39, respectively ...
Ahmed Elabasy, Heta Helakari, Tommi Väyrynen, Zalán Rajna, Niko Huotari, Lauri Raitamaa, Ville Isokoski, Matti Järvelä, Mika Kaakinen, Johanna Piispala, Mika Kallio, Vesa Korhonen, Tapio Seppänen, Vesa Kiviniemi   +13 more
wiley   +1 more source