Mid Sweden University

The aim of this project was to develop a wind tunnel that enables the study of human performance during various types ofsports and physical activities by examining the influence of aerodynamic drag, precipitation, frictional forces and gravitationalforces on uphill and downhill travel on a moving substrate. An overall design for a wind tunnel and working section containinga large treadmill was drafted, followed by computational fluid dynamics simulations of flow conditions to assess thedesign’s feasibility and select from different geometries prior to its construction. The flow conditions in the completed windtunnel were validated using different flows, speeds and treadmill inclinations. Pilot experiments were carried out using across-country skier to investigate the effect of aerodynamic drag on oxygen uptake during double poling and the maximalachieved speed when rolling on a declined treadmill. The purpose was to validate the usefulness of the tunnel. The resultsshowed that flow conditions are acceptable for experiments even in worst-case scenarios with maximal inclined and declinedtreadmill. Results also showed that aerodynamic drag has a significant impact on the skier’s energy expenditure.