Some Results on Bobsleigh Aerodynamics

Bobsleighs races nowadays are decided upon hundredths of a second. As the margins are that small the aerodynamics of a bobsleigh can play a significant role in a race outcome. This paper investigates the influence of the gap between the nose and the rear cowling of a two-man bobsleigh. The paper especially focusses on the misalignment between both cowling parts due to lateral rotation in a track bend. CFD analyses and wind tunnel tests have shown that the rotation of the nose increases the drag due to an enlarged frontal area and due to adverse effects of the airstream flowing into the cavity. The results are used to define an area of investigation to alter the gap geometry which may lead to reduced drag when the bobsleigh parts are misaligned.