Analysis of acceleration and numerical modeling of skeleton sled motion

Abstract

The skeleton is a high-speed sport achieving speeds up to 130 km•h-1 on an ice track, but conditions for faster sliding have not been documented. This paper describes a theoretical model, an experiment and numerical modelling to evaluate the effect of air drag and runner stiffness. A mathematical model was determined for the forward motion of the skeleton down an angled straight ice track that included vertical motion to consider vibrations from a rough ice track. Numerical modelling results were compared with experimental tests performed at a bobsled push-start facility. The skeleton sliding time was logged at the start and end of a 23.7 m long ice track. The motion was registered by a portable accelerometer attached to the centre of mass on the skeleton base plate. Acceleration down the ice track axis was numerically integrated to calculate the speed and the distance with time. Numerical modelling showed that the speed increased linearly, and the 23.7 m were too short to see the effect of air drag and runner stiffness on the sliding time. Modelling results showed that despite faster sliding times at conditions of lower air drag, the runner started to vibrate earlier leading to less stable sliding conditions. A higher runner stiffness delayed the onset of vibration. Modelling not only showed conditions that could lead to faster sliding, but also predicted the stability of the skeleton slide, over a longer distance that is available at push-start facilities.

Modelling of stiffness variability of skeleton sled on inclined ice plane

“…Previous studies looked at the movement of the skeleton sleigh on inclined harmonious function profile of roughness with variable runner stiffness [1]. How the movement is affected by the resistance forces -the air resistance C D and the ice friction coefficient f -was analyzed.…”

Investigation of Vibration Induced by Sliding Down an Ice Plane

“…The aim of the study is to determine whether it is possible to distinguish the quality of the surface from data of acceleration of the sample in axial directions using a portable accelerometer. More extensive studies have modelled the effect of road roughness on motion [3]. Despite the changing characteristics of ice surfaces, it is valuable to know how the surface influences the sliding motion over ice.…”