Non-contact torque measurement on a rotating shaft incorporating a mechanical resonator

1999 ◽  
Author(s):  
N. Whitehead
Keyword(s):  
Torque Measurement ◽  
Mechanical Resonator ◽  
Rotating Shaft

Drag Reduction of Surfactant Solutions for an Enclosed Rotating Disk

1999 ◽  
Author(s):  
Satoshi Ogata ◽  
Keizo Watanabe
Keyword(s):  
Drag Reduction ◽  
Pipe Flow ◽  
Transition Point ◽  
Rotating Disk ◽  
Torque Measurement ◽  
Rotating Disks ◽  
Rotating Shaft ◽  
Surfactant Solutions ◽  
Circular Pipe Flow ◽  
Maximum Drag Reduction

Abstract Recently, many studies on surfactant solutions have been conducted for drag reduction in a circular pipe flow. However, currently there are very few studies on rotating disks in the solutions. In this study, drag reduction for an enclosed rotating disk in surfactant solutions was clarified experimentally. Experiments were carried out to measure the torque acting on one side of a rotating disk, using a torque measurement device located at the top of the rotating shaft. Test surfactant solutions were Ethoquad O/12 at concentrations of 50, 100 and 200ppm. The temperatures of solutions were 18°C and 28°C. The clearances between the disk and the stator were 10mm and 20mm. It was shown that the Reynolds number at the transition point increased with increasing concentration and temperature of these solutions. The maximum drag reduction ratio was about 41% in 200ppm Ethoquad O/12 solution at 28°C.

Bisynchronous Torsional Vibrations in Rotating Shafts

1987 ◽  
Vol 54 (4) ◽  
pp. 893-897 ◽  
Author(s):  
O. Bernasconi
Keyword(s):  
Angular Momentum ◽  
Nonlinear Term ◽  
Rotation Frequency ◽  
Longitudinal Component ◽  
Torsional Vibrations ◽  
Rotating Shaft ◽  
Rotating Shafts

In this study, the intrinsic behavior of rotating shafts with residual unbalance is considered. The longitudinal component of the angular momentum caused by synchronous precession (whirling) induces torsional vibrations with a frequency of twice the rotation frequency (bisynchronous). The nonlinear term which represents this coupling is characteristic of the asymmetrical aspect of rotating shaft kinematics. This result has been obtained analytically and confirmed experimentally.

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