scholarly journals The Motion of Rapidly Rotating Curling Rocks

1999 ◽  
Vol 52 (6) ◽  
pp. 1025 ◽  
Author(s):  
Mark R. A. Shegelski ◽  
Ross Niebergall
Keyword(s):  
Liquid Film ◽  
Relative Velocity ◽  
Thin Liquid Film ◽  
Translational Motion ◽  
Slow Rotation ◽  
Kinetic Friction ◽  
Centre Of Mass ◽  
Ice Surface ◽  
Translational Speed ◽  
Careful Comparison

We present a physical model that accounts for the motion of rapidly rotating curling rocks. By rapidly rotating we mean that the rotational speed of the contact annulus of the rock about the centre of mass is large compared with the translational speed of the centre of mass. The principal features of the model are: (i ) that the kinetic friction induces melting of the ice, with the consequence that there exists a thin film of liquid water lying between the contact annulus of the rock and the ice; (ii ) that the curling rock drags some of the thin liquid film around the rock as it rotates, with the consequence that the relative velocity between the rock and the thin liquid film is significantly different to the relative velocity between the rock and the underlying solid ice surface. Since it is the former relative velocity which dictates the nature of the motion of the curling rock, our model predicts some interesting differences between the motions of slowly versus rapidly rotating rocks. Of principal note is that our model predicts, and observations confirm, that rapidly rotating curling rocks stop moving translationally well before rotational motion ceases. This is in sharp contrast to the usual case of slow rotation, where both rotational and translational motion cease at the same instant. We have verified this and other predictions of our model by careful comparison with the motion of actual curling rocks.

The motion of rotating cylinders sliding on pebbled ice

2000 ◽  
Vol 77 (11) ◽  
pp. 847-862 ◽  
Author(s):  
MRA Shegelski ◽  
M Reid ◽  
R Niebergall
Keyword(s):  
Thin Film ◽  
Liquid Film ◽  
Contact Area ◽  
Relative Velocity ◽  
Thin Liquid Film ◽  
Center Of Mass ◽  
Translational Motion ◽  
Rotating Cylinder ◽  
Outer Edge ◽  
Slow Rotation

We consider the motion of a cylinder with the same mass and sizeas a curling rock, but with a very different contact geometry.Whereas the contact area of a curling rock is a thin annulus havinga radius of 6.25 cm and width of about 4 mm, the contact area of the cylinderinvestigated takes the form of several linear segments regularly spacedaround the outer edge of the cylinder, directed radially outward from the center,with length 2 cm and width 4 mm. We consider the motion of this cylinderas it rotates and slides over ice having the nature of the ice surfaceused in the sport of curling. We have previously presented a physicalmodel that accounts for the motion of curling rocks; we extend this modelto explain the motion of the cylinder under investigation. In particular,we focus on slow rotation, i.e., the rotational speed of the contact areasof the cylinder about the center of mass is small compared to thetranslational speed of the center of mass.The principal features of the model are (i) that the kineticfriction induces melting of the ice, with the consequence that thereexists a thin film of liquid water lying between the contact areasof the cylinder and the ice; (ii) that the radial segmentsdrag some of the thin liquid film around the cylinder as it rotates,with the consequence that the relative velocity between the cylinderand the thin liquid film is significantly different than the relativevelocity between the cylinder and the underlying solid ice surface.Since it is the former relative velocity that dictates the nature of themotion of the cylinder, our model predicts, and observations confirm, thatsuch a slowly rotating cylinder stops rotating well before translationalmotion ceases. This is in sharp contrast to the usual case of most slowlyrotating cylinders, where both rotational and translational motion ceaseat the same instant. We have verified this prediction of our model bycareful comparison to the actual motion of a cylinder having a contactarea as described.PACS Nos.: 46.00, 01.80+b

The motion of a curling rock

1996 ◽  
Vol 74 (9-10) ◽  
pp. 663-670 ◽  
Author(s):  
Mark R. A. Shegelski ◽  
Ross Niebergall ◽  
Mark A. Walton
Keyword(s):  
Thin Film ◽  
Liquid Film ◽  
Physical Model ◽  
Liquid Water ◽  
Dry Friction ◽  
Thin Liquid Film ◽  
Kinetic Friction ◽  
Contact Areas ◽  
Wet Friction

We present a plausible physical model that accounts for the motion of a curling rock. The principal features of the model are (i) that the kinetic friction induces melting of the ice with the consequence that the curling rock experiences both "dry friction," when encountering solid ice, as well as "wet friction," for contact areas that pass over the thin film of liquid water lying above the ice; (ii) that the wet friction is velocity dependent; and (iii) that the curling rock is able, in its last stages of motion, to drag some of the thin liquid film part way around the rock, which significantly enhances the curl of the rock. We compare the model to actual trajectories of curling rocks.

scholarly journals The motion of curling rocks: Experimental investigation and semi-phenomenological description

2004 ◽  
Vol 82 (10) ◽  
pp. 791-809 ◽  
Author(s):  
E T Jensen ◽  
Mark RA Shegelski
Keyword(s):  
Experimental Investigation ◽  
Liquid Film ◽  
Frictional Force ◽  
Dry Friction ◽  
Thin Liquid Film ◽  
Ice Surface ◽  
Wet Friction ◽  
Wide Range ◽  
Friction Models ◽  
Rule Out

A large number of curling shots using a wide range of rotational and translational velocities on two different ice surfaces have been recorded and analyzed. The observed curling-rock trajectories are described in terms of a semi-phenomenological model. The data are found to rule out "dry-friction" models for the observed motion, and to support the idea that the curling rock rides upon a thin liquid film created at the ice surface (i.e., "wet friction"). Evidence is found to support the hypothesis that the frictional force acting upon each segment of the curling rock is directed opposite to the motion relative to this thin liquid film and not relative to the underlying fixed ice surface. PACS No.: 01.80.+b

scholarly journals Visualization of Surface Acoustic Waves in Thin Liquid Films

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
R. W. Rambach ◽  
J. Taiber ◽  
C. M. L. Scheck ◽  
C. Meyer ◽  
J. Reboud ◽  
...  
Keyword(s):  
Liquid Film ◽  
Acoustic Waves ◽  
Low Cost ◽  
Thin Liquid Film ◽  
Surface Acoustic Waves ◽  
Liquid Films ◽  
Theoretical Description ◽  
Propagation Path ◽  
Microfluidic Channels ◽  
Potential Applications

Abstract We demonstrate that the propagation path of a surface acoustic wave (SAW), excited with an interdigitated transducer (IDT), can be visualized using a thin liquid film dispensed onto a lithium niobate (LiNbO3) substrate. The practical advantages of this visualization method are its rapid and simple implementation, with many potential applications including in characterising acoustic pumping within microfluidic channels. It also enables low-cost characterisation of IDT designs thereby allowing the determination of anisotropy and orientation of the piezoelectric substrate without the requirement for sophisticated and expensive equipment. Here, we show that the optical visibility of the sound path critically depends on the physical properties of the liquid film and identify heptane and methanol as most contrast rich solvents for visualization of SAW. We also provide a detailed theoretical description of this effect.

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