A New Drag Measurement System for Wind Tunnel Testing of the Racing Bicycle and Rider to Determine a Low Drag Configuration.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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This study investigated the application of splitter plate effects to reduce the aerodynamic drag of the racing bicycle and rider system. A sensitive, low-force, beam-type, single-component balance was developed to provide drag measurements accurate to within 0.053 N 0.012 lbf. The performance of the new system was verified by comparing the measured drag on a three-dimensioaal, right-circular cylinder model, 0.127 m 5.0 in in diameter and 0.610 m 24 in long, with the results from a commercial balance and a other similar data. The bicycle and rider model consisted of a full-scale mannequin comprising only the hips, legs and feet, mounted on a regulation 0.48 m 19 in size bicycle. Rotation of the wheels and a stationary ground plane were also simulated. Two frame configurations in conjunction with a disk type wheel were tested to determined the lowest drag configuration for narrow and wide spacing of the riders legs. The results show that for the standard tube construction frame, the conventional wisdom to streamline as much as possible prevails. When an aerodynamic frame was tested, the overall drag was reduced. Although the standard spacing still provided the lowest drag configuration, any further streamlining showed an increase in drag.
- Surface Transportation and Equipment
- Fluid Mechanics