| Résumé | Ice friction affects us in many ways, from slippery roads to winter sports. In cold regions, ice friction influences ice interaction with itself, which determines the motion of ice floes. It also influences the structural forces resulting from ice interactions with fixed and moored structures and with floating vessels. Ice friction also affects surface transportation over snow and ice. This paper addresses only one aspect of ice friction in winter sports, but it is potentially relevant to other applications, particularly surface transportation over ice. The model of ice friction described here is for a steel bobsleigh runner sliding on ice at high velocity. The model describes ice friction in the fully-lubricated, hydrodynamic regime, where a layer of meltwater completely separates the ice and slider surfaces. The effect of any contact between asperities on both surfaces is neglected. Friction results from a ploughing force, arising from ice deformation, crushing and extrusion, and from the shear stress in the lubricating Couette flow. The model takes into account frictional melting, heat conduction into the ice and the lateral squeeze flow of the lubricating liquid. The effect of pressure on the melting temperature is also accounted for. Sensitivity testing of the numerical model has been conducted to examine the influence of such factors as runner dimensions, sliding speed, ice temperature and g-forces. A comparison with recent measurements of bobsled ice friction made by one of the authors is encouraging, suggesting that the model has identified and adequately represented the most essential physical processes. Copyright © 2013 by the International Society of Offshore and Polar Engineers (ISOPE). |
|---|
