This paper briefly describes a computational model developed by our group to calculate the coefficient of friction between a steel blade and ice. We then discuss two experiments executed to specify certain aspects of the computational model. We measured the ice hardness of five athletic ice surfaces and found it to be ((−0.6 ± 0.4)T + (14.7 ± 2.1)) MPa. We also measured the coefficient of friction between steel blades (runners) and ice at low speeds and during a World Cup 2-men bobsleigh competition as = (5.3 ± 2.0) × 10-3.
While the low coefficient of friction of ice is well known, it is not well understood. In a survey of the subject, Rosenberg (2005) examines the major aspects of the issue. We have developed a numerical model, based on hydrodynamic lubrication, to predict friction on ice. We are using this model to calculate the coefficient of friction between ice and the blades of speed skates and bobsleds. Our goal is to optimize the shape of the blade in order to minimize friction and improve performance in the sports of speed skating and bobsleigh. In this paper, we briefly review the components of the numerical model and discuss two experiments we performed to specify and validate aspects of the model. THE F.A.S.T. MODEL We call the model Frictional Algorithm for Skate Thermohydrodynamics (F.A.S.T.) (Penny et al., 2007). First, the model calculates the force required to plow through the ice. Specifically, it is the product of the ice hardness and the cross-sectional area of the indentation left in the ice perpendicular to the axis of motion. We assume that the ice applies a constant pressure over the entire contact area. This assumption is supported by the experiments of Martel (1895).
