Results 141 to 150 of about 188,936 (312)
Results of the 1986 NASA/FAA/DFVLR main rotor test entry in the German-Dutch wind tunnel (DNW) [PDF]
An acoustics test of a 40%-scale MBB BO-105 helicopter main rotor was conducted in the Deutsch-Niederlandischer Windkanal (DNW). The research, directed by NASA Langley Research Center, concentrated on the generation and radiation of broadband noise and ...
Brooks, Thomas F., Martin, Ruth M.
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Liquid Jetting‐Based Miniature Robotic Navigation in Confined Fluidic Spaces
Advanced Intelligent Systems, EarlyView.We introduce a new class of liquid‐jetting‐based miniature robots (JetBots) ranging in size from mm‐to‐cm, featuring a unified approach in design, fabrication, and actuation. They demonstrate fast locomotion (30.3 cm/s), rapid steering (648.8°/s), and diverse functions, such as puncturing soft materials and unlimited cargo sampling and delivery, paving
Debasish Roy, Tianlu Wang
wiley +1 more source
Research investigation of helicopter main rotor/tail rotor interaction noise [PDF]
Acoustic measurements were obtained in a Langley 14 x 22 foot Subsonic Wind Tunnel to study the aeroacoustic interaction of 1/5th scale main rotor, tail rotor, and fuselage models.
Fitzgerald, J., Kohlhepp, F.
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Controlling the Guanidinium Cation Rotation by Cation–π Interactions
Angewandte Chemie International Edition, EarlyView.A lanthanide π‐container has been employed to trap a guanidinium cation inside the aromatic cavity by cation–π interactions. X‐ray crystallography and solid‐state nuclear magnetic resonance (NMR) spectroscopy at fast magic‐angle spinning (MAS) frequencies have been utilized to probe the underlying host–guest interactions.
Hannah Busch +12 more
wiley +1 more source
Helicopter main-rotor noise: Determination of source contributions using scaled model data [PDF]
Acoustic data from a test of a 40 percent model MBB BO-105 helicopter main rotor are scaled to equivalent full-scale flyover cases. The test was conducted in the anechoic open test section of the German-Dutch Windtunnel (DNW).
Brooks, Thomas F. +2 more
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Piezoceramics-based Devices for Active Balancing of Flexible Shafts [PDF]
, 2006 This paper focuses on vibration control of flexible shafts by means of rotorfixed piezoelectric materials. The target is to realize compact solutions for the suppression of problematic resonant vibration at so-called flexural critical speeds.
Boer, A. de, Sloetjes, P.J.
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Journal of the American Oil Chemists' Society, EarlyView.ABSTRACT In oil‐in‐water emulsions, lipid oxidation begins at the interface between the two phases. One strategy to slow down this process is to place antioxidants at the interface, where they can directly block oxidative reactions. This study explored that idea by conjugating soluble faba bean protein with tannic acid using the free‐radical grafting ...
Shahrzad Sharifimehr, Supratim Ghosh
wiley +1 more source
Complexity Analysis of Bubble Plumes in Power Law Fluids Based on Chaos Theory
Asia-Pacific Journal of Chemical Engineering, EarlyView.ABSTRACT In order to reveal the complexity of the internal flow of bubble plume in power law fluid, the flow characteristics and chaotic characteristics of plume are studied by experiment and theory. The chaotic characteristic parameters (correlation dimension D, K entropy, and Lyapunov exponent λ) of gas velocity under different superficial gas ...
Xin Dong +6 more
wiley +1 more source
TASK Quarterly, 2013 The paper presents the results of numerical simulations based on the URANS approach and the chimera overlapping grids technique of the main PZL W-3A “Sokół” (Falcon) helicopter rotor in forward flight conditions.
OSKAR SZULC +3 more
doaj
Experimental blade vortex interaction noise characteristics of a utility helicopter at 1/4 scale [PDF]
Models of both the advanced main rotor system and the standard or "baseline" UH-1 main rotor system were tested at one-quarter scale in the Langley 4- by 7-Meter (V/STOL) Tunnel using the general rotor model system.
Conner, D. A., Hoad, D. R.
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