Results 231 to 240 of about 337,376 (283)

Rotating-Blade Vortex Noise

Proceedings of the Symposium on Status of Testing and Modeling Techniques for V/STOL Aircraft, Philadelphia 1972, 1972
An experimental investigation has been made in the Langley full-scale tunnel and outdoors to investigate some of the characteristics of vortex noise generated on a rotating-blade system. Acoustic measurements were made at several microphone positions for two different blade sections with several tip shapes and spoiler configurations.
James Scheiman, William Letko, James Shivers, David Hilton   +3 more
openaire   +1 more source

Vibrations of Twisted Rotating Blades

Journal of Vibration and Acoustics, 1984
The literature dealing with vibrations of turbomachinery blades is voluminous, but the vast majority of it treats the blades as beams. In a previous paper a two-dimensional analytical procedure was developed and demonstrated on simple models of blades having camber.
A. W. Leissa, J. K. Lee, A. J. Wang
openaire   +1 more source

An OPR-Free Blade Tip Timing Method for Rotating Blade Condition Monitoring

IEEE Transactions on Instrumentation and Measurement, 2021
Blade tip timing (BTT) is a noncontact blade vibration measurement method for rotating blade condition monitoring. However, it is difficult to install a once-per-revolution (OPR) probe due to the internal environment limitation of an engine. To solve this problem, an OPR-free BTT method is proposed in this article.
Zengkun Wang, Zhibo Yang 0001, Shuming Wu, Haoqi Li, Shaohua Tian, Xingwu Zhang, Ruqiang Yan 0001, Xuefeng Chen 0002   +7 more
openaire   +2 more sources

The Laminar Boundary Layer on a Rotating Blade

Journal of the Aeronautical Sciences, 1951
Boundary-layer equations of motion for a blade rotating steadily in an incompressible fluid are developed. The equations show that , at stations several chord lengths from the axis of rotation of a thin blade, the chordwise velocity is independent of the spanwise velocity due to rotation; hence, the separation line is unaffected by rotation.
openaire   +2 more sources

Analysis of Incompressible, Nonviscous Blade-to-Blade Flow in Rotating Blade Rows

Journal of Fluids Engineering, 1958
Abstract A method is developed for the blade-to-blade solution of the incompressible, nonviscous flow through rotating blade rows (including the inlet region) with or without splitter vanes. Splitter vanes are partial blades which do not extend to the inlet of the blade row.
openaire   +1 more source

One-blade rotation of a persistent posterior vertex

American Journal of Obstetrics and Gynecology, 1991
Fifteen women in labor at term with no evidence of protraction or arrest disorder successfully underwent a single-blade rotation of the fetus from occipitoposterior to occipitoanterior position. There were no failures, no fetal injuries, and no significant maternal trauma.
J O, Escamilla, S J, Carlan
openaire   +2 more sources

Stress Analysis of the Rotating Circular Saw Blade

Solid State Phenomena, 2017
The article deals with the determination of parameters of longitudinal wood cutting by circular saw blade and construction of the cutting tool. A computational model was chosen to determine stress of the rotating circular saw blade. Stress analysis revealed that maximal stress caused by the temperature gradient was approximately ten times higher than ...
Bílek, Ondřej, Kovařík, Martin
openaire   +2 more sources

Rotating blades and aerodynamic sound

Journal of Sound and Vibration, 1973
The history of research on rotating blade noise is reviewed, from early studies of propeller radiation to current work on aircraft-engine fans. The survey is selective, with emphasis on fundamental aspects of aerodynamic sound generation by blades. The topics covered include the following: early research on propeller noise, unsteady airfoil theory ...
openaire   +1 more source

Physics-Guided Sound Synthesis for Rotating Blades

2020
This paper focuses on sound synthesis for rotating blades such as fans, helicopters and wind turbines, which is common in both real world and computer games though has received little attention until now. In this paper, we propose a novel physics-guided sound synthesis method for rotating blades.
Siqi Xu, Shiguang Liu
openaire   +2 more sources

The Acoustic Analogy and the Prediction of the Noise of Rotating Blades

Theoretical and Computational Fluid Dynamics, 1998
The paper focuses on the prediction of the noise of rotating machinery. The governing Ffowcs Williams-Hawkings (FW-H) equation for this problem is a wave equation for perturbation density with three source terms, which are known as thickness, loading, and the quadrupole source terms.
Farassat, F., Brentner, Kenneth S.
openaire   +2 more sources