On the role of thickness ratio and location of axis of rotation in the flat plate motions

AbstractWe study the role of small-scale perturbations in the onset of avalanches in a rotating drum in the stick-slip regime. By vibrating the system along the axis of rotation with an amplitude orders of magnitude smaller than the particles’ diameter, we found that the order parameter that properly describes the system is the kinetic energy. We also show that, for high enough frequencies, the onset of the avalanche is determined by the amplitude of the oscillation, contrary to previous studies that showed that either acceleration or velocity was the governing parameter. Finally, we present a theoretical model that explains the transition between the continuous and discrete avalanche regimes as a supercritical Hopf bifurcation.

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Sensorimotor aspects of high-speed artificial gravity: II. The effect of head position on illusory self motion

Journal of Vestibular Research ◽

10.3233/ves-2003-125-608 ◽

2003 ◽

Vol 12 (5-6) ◽

pp. 283-289

Author(s):

Fred W. Mast ◽

Nathaniel J. Newby ◽

Laurence R. Young

Keyword(s):

Healthy Subjects ◽

Horizontal Plane ◽

High Speed ◽

Semicircular Canals ◽

Vertical Axis ◽

Head Position ◽

Artificial Gravity ◽

Axis Of Rotation ◽

Self Motion

The effects of cross-coupled stimuli on the semicircular canals are shown to be influenced by the position of the subject's head with respect to gravity and the axis of rotation, but not by the subject's head position relative to the trunk. Seventeen healthy subjects made head yaw movements out of the horizontal plane while lying on a horizontal platform (MIT short radius centrifuge) rotating at 23 rpm about an earth-vertical axis. The subjects reported the magnitude and duration of the illusory pitch or roll sensations elicited by the cross-coupled rotational stimuli acting on the semicircular canals. The results suggest an influence of head position relative to gravity. The magnitude estimation is higher and the sensation decays more slowly when the head's final position is toward nose-up (gravity in the subject's head x-z-plane) compared to when the head is turned toward the side (gravity in the subject's head y-z-plane). The results are discussed with respect to artificial gravity in space and the possible role of pre-adaptation to cross-coupled angular accelerations on earth.

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Spatial Coherence in the Wake of a Flat Plate

Applied Mechanics Reviews ◽

10.1115/1.3101846 ◽

1997 ◽

Vol 50 (11S) ◽

pp. S36-S38

Author(s):

Jose´ B. Da´vila ◽

Muhammad R. Hajj ◽

Richard W. Miksad ◽

Edward J. Powers

Keyword(s):

Wind Tunnel ◽

Resonant Frequency ◽

Flat Plate ◽

Spatial Coherence ◽

Streamwise Velocity ◽

Coupled Mode ◽

Streamwise Velocity Fluctuation ◽

Mode Energy ◽

Made In

Spatial coherence of the streamwise velocity fluctuation was measured in the wake of a flat plate in a wind tunnel. The measurements were made in the context of determining the role of wavenumber resonance in quadratic interactions among resonant frequency modes. Frequency domain results show that sum-interaction modes targeted by coupled mode pairs are spatially coherent. This suggests that spatial coherence measurements can be combined with bispectral measurements to determine mode energy transit and direction.

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Role of the Plate-motions on the Development of Inner Arc Basins as Exemplified by the Tertiary of North Kyusyu.

Journal of Geography (Chigaku Zasshi) ◽

10.5026/jgeography.102.7_849 ◽

1993 ◽

Vol 102 (7) ◽

pp. 849-867 ◽

Cited By ~ 8

Author(s):

Tsugio SHUTO

Keyword(s):

Plate Motions

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Autorotating flat-plate wings: the effect of the moment of inertia, geometry and Reynolds number

Journal of Fluid Mechanics ◽

10.1017/s0022112079000641 ◽

1979 ◽

Vol 92 (2) ◽

pp. 327-348 ◽

Cited By ~ 67

Author(s):

J. D. Iversen

Keyword(s):

Reynolds Number ◽

Aspect Ratio ◽

Flat Plate ◽

Plate Thickness ◽

Thickness Ratio ◽

Moment Of Inertia ◽

Speed Ratio ◽

Free Flight ◽

Tip Speed Ratio ◽

The Moment

Free-flight and wind-tunnel measurements by previous investigators of the flat-plate autorotation phenomenon have been analysed. The variation of the autorotation characteristics with changes in the Reynolds number and the aspect ratio, thickness ratio and moment of inertia of the flat plate have been correlated. The interpretation of the role of the Reynolds number made in a previous investigation is shown to be incorrect. The tip-speed ratio, for the ranges of the dimensionless parameters investigated, is shown to be a function of only the plate aspect ratio, thickness ratio, and also the moment of inertia if the latter is sufficiently small. The lift and drag coefficients, and therefore the free-flight glide angle, are shown to be functions of the tip-speed ratio, the aspect ratio and the Reynolds numbers based on the chord and plate thickness.

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Role of crack length, crack spacing and layer thickness ratio in the electric potential and temperature of thermoelectric bi-materials systems

Engineering Fracture Mechanics ◽

10.1016/j.engfracmech.2021.108170 ◽

2021 ◽

pp. 108170

Author(s):

Dongdong Jiang ◽

Yue-Ting Zhou

Keyword(s):

Crack Length ◽

Layer Thickness ◽

Electric Potential ◽

Thickness Ratio ◽

Crack Spacing ◽

Layer Thickness Ratio

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The Effect of Initial Curvature in a Flexible Disk Rotating Near a Flat Plate

Journal of Tribology ◽

10.1115/1.2920629 ◽

1991 ◽

Vol 113 (2) ◽

pp. 355-360 ◽

Cited By ~ 7

Author(s):

M. Carpino

Keyword(s):

Flat Plate ◽

Rigid Plate ◽

Governing Equations ◽

Initial Curvature ◽

Axis Of Rotation ◽

Flexible Disk

The effect of initial curvature in a disk which is rotated close to a rigid flat plate is analyzed in this paper. When the unconstrained disk is not rotating, it has an initial curvature perpendicular to the axis of rotation. A thin gas film separates the disk from the rigid plate when the disk is rotating. The governing equations for this system are presented and solved.

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