Experimental study of high-speed friction on ice

Kozlov, I. I.; Shugai, A. A.

doi:10.1007/bf01050128

Cited by 9 publications

(4 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Formula (4), e.g., indicates that water films with a thickness of up to h a ∼ 10 -7 -10 -6 m can be formed during ice friction at v ~ 1 m/s, μ ~ 1 Pa s, T m ~ 273 K, T int ∼ 265 ä, T ω ∼ 275 ä, k ~ 0.6 W/(m K), k ice ~ 2.35 W/(m K), ρ ice ∼ 0.9 × 10 3 kg m -3 , c ice ~ 2039 J (kg K) -1 , and l ∼ 10 -3 m. This estimate agrees with the results of corresponding experiments (Kozlov and Shugai, 1991). Formula (4), e.g., indicates that water films with a thickness of up to h a ∼ 10 -7 -10 -6 m can be formed during ice friction at v ~ 1 m/s, μ ~ 1 Pa s, T m ~ 273 K, T int ∼ 265 ä, T ω ∼ 275 ä, k ~ 0.6 W/(m K), k ice ~ 2.35 W/(m K), ρ ice ∼ 0.9 × 10 3 kg m -3 , c ice ~ 2039 J (kg K) -1 , and l ∼ 10 -3 m. This estimate agrees with the results of corresponding experiments (Kozlov and Shugai, 1991).…”

Section: Model Of Water Vapor Explosive Eruptionsupporting

confidence: 89%

“…In this case, thin water films can be formed at the ice grain boundaries due not only to the motion of the dislocations toward the grain boundaries, but also the mutual friction of the grains (Budnevich and Deryagin, 1952;Amosov, 1982;Oksanen and Keinonen, 1982;Kozlov and Shugai, 1991;Maenoa and Arakawa, 2004). In this case, thin water films can be formed at the ice grain boundaries due not only to the motion of the dislocations toward the grain boundaries, but also the mutual friction of the grains (Budnevich and Deryagin, 1952;Amosov, 1982;Oksanen and Keinonen, 1982;Kozlov and Shugai, 1991;Maenoa and Arakawa, 2004).…”

Section: Model Of Water Vapor Explosive Eruptionmentioning

confidence: 99%

See 1 more Smart Citation

10.1007/s11208-008-2004-x

2010

CrossRef Listing of Deleted DOIs

View full text Add to dashboard Cite

The possibility of generating water vapor and other gaseous products during nonvolcanic explosive eruptions in lithospheres of icy satellites is discussed. Explosive eruptions of ice, with its fragmentation into micro-and nanofragments, can occur in the extensive deep layers of such icy satellites as Europa, Ganymede, Enceladus, etc., if giant cracks are episodically formed in the lithospheres of these satellites. Such cracks can be produced by tidal forces, synchronous resonances of satellites, or especially powerful impacts. The model is based on the recently obtained experimental evidence that explosive ice instability (Bridgman effect) is formed at a strong nonuniform compression in the regions of high pressures and low temperatures. Water films, the thicknesses of which reach several microns, can be formed during the process of the mutual friction of ice fragments during their quasi-liquid flow at the instant of an explosive eruption. About 1-10 dm 3 of a water film can be produced in 1 m 3 of erupted ice fragments. Water vapor can be formed from a water film when this water boils up after a rapid pressure drop as a result of an ice-water mixture eruption from cracks. A certain amount of gaseous products in the form of hydrogen, oxygen, and ammonia molecules and radicals on their basis can be generated during the sputtering induced by electrons and ions and the dissociation of nanofragments of ice during the process of ice explosive fragmentation as a result of fracto-, tribo-, and secondary emission. The estimates indicate that the volume of water vapor erupted on satellites can be larger than that of discharged ionized gases by a factor of not less than 10 5 -10 7 . Water vapor and microscopic ice fragments can be erupted from cracks in the lithospheres of small Enceladus-type satellites at velocities higher than the second cosmic velocity. Gaseous products generated in such episodic processes can, most probably, substantially contribute to the density of the atmosphere that exists on small icy satellites, but can only insignificantly contribute to this density on large satellites. The stick-slip motions of the most condensed plumes of water vapor and dust, normal to the satellite surface, along the mouths of gigantic cracks may indicate that the proposed model is realistic. Such wanderings of water vapor plumes can result in the synchronous motions of thermal patches on the satellite surface along crack mouths at velocities of about 10 km/h.

show abstract

Section: Model Of Water Vapor Explosive Eruptionsupporting

confidence: 89%

Section: Model Of Water Vapor Explosive Eruptionmentioning

confidence: 99%

10.1007/s11208-008-2004-x

2010

CrossRef Listing of Deleted DOIs

View full text Add to dashboard Cite

show abstract

“…As already stated, a single contact is assumed both for the skates (perpendicularly below the corresponding axle) and for the buffers (at the centre of the buffers). This means that multiple contacts, that may occur in presence of high normal loads and/or on rough ice surfaces, are neglected due to lack of experimental data and the limited literature developed on the subject [10][11][12][13][14]. Moreover, the resulting forces of contact pressure (normal contact force) and shear stress (longitudinal and lateral contact forces) distributions are considered.…”

Section: Contact Modelmentioning

confidence: 99%

A driver model of a two-man bobsleigh

et al. 2011

View full text Add to dashboard Cite

Up to now, the optimization of structural parameters affecting the performance of a bobsleigh has been carried out mainly on the basis of athletes’ feedback, thus leading to a series of small modifications without univocal guidelines. Even though on-track tests represent a basic step for the final tuning of the sled, experimentation does not seem to represent an appropriate tool to objectively determine the influence of such structural parameters on the overall performance. In fact, their effect can easily be masked by driving errors, changes in the ice surface conditions and temperature thus requiring repeated tests for achieving statistical evidence. For this reason, numerical analysis, carried out with a 3D model of the bobsled, turns out to be a privileged instrument to optimize bob design although limitations in the sled model (e.g. ice friction properties that still have to be fully understood) may affect the obtained results. However, such tool is able to provide useful indications only if a correct driver model is implemented. This work focuses on the development of a numerical model of a bobsleigh driver that aims at reproducing the driving behaviour of real-world cup drivers and is basically made up of two steps: the identification of the trajectory that allows minimizing run time and the determination of the driver’s inputs to exactly follow that trajectory. For comparison purposes, the simulated driver’s inputs are compared with recorded ones on Cesana Pariol Olympic track

show abstract

“…Friction facilitated by a lubricating layer of no more than a few molecular layers is known as boundary friction. This thin layer reduces solid–solid contact at the interface, while the slider’s load is mainly supported by the surface asperities (Kozlov and Shugai, 1991; Bhushan, 2002). In the mixed friction regime the load of the slider is supported by both the surface asperities and the lubricating layer, which is thicker than in the boundary friction regime.…”

Section: Introductionmentioning

confidence: 99%

Ice friction: the effect of thermal conductivity

Kietzig¹,

Hatzikiriakos²,

Englezos³

2010

J. Glaciol.

View full text Add to dashboard Cite

The effect of thermal conductivity on ice friction is studied systematically for different metallic slider materials over a wide range of temperatures, and sliding velocities. By thermally insulating the slider with fiberglass, the isolated effect of thermal conductivity on ice friction is investigated. A decrease of the friction coefficient in the boundary friction regime and an earlier onset of the mixed friction regime in terms of sliding velocity are found. Furthermore, the dependence of the ice friction coefficient on sliding velocity is compared for different sliding materials. It is found that the influence and importance of thermal conductivity decreases with increasing sliding velocity.

show abstract

Experimental study of high-speed friction on ice

Cited by 9 publications

References 1 publication

10.1007/s11208-008-2004-x

10.1007/s11208-008-2004-x

A driver model of a two-man bobsleigh

Ice friction: the effect of thermal conductivity

Contact Info

Product

Resources

About