Aerodynamic Effects by Marathon Pacemakers on a Main Runner

Abstract

A slipstream is a region of reduced pressure or even suction (negative pressure) formed behind an object in downstream. Even in a marathon event, it is possible to use preceding runners as a shield to reduce aerodynamic drag and to carry out physical strength presservation. These preceding runners are called pacemakers, who maintain a lap time of an main runner. In this research, to confirm the effect of pacemakers' slipstream and to find a suitable arrangement of pacemakers, drag of the main runner was measured using 3 component load cells in a wind tunnel. And the factor of drag reduction was studied by grasping the flow field using a smoke tunnel. Numerical calculations were also carried out in a real Reynolds number and compared with experiments concerning drag and flow field.