Drag Force Reduction in Swimming

The purpose of this experiment was to determine if there is a length at which the reduction of drag, created by wearing a swim cap, becomes insignificant. To conduct the experiment a 150-gallon stock tank was filled with water and a ResuciAnne head was pulled through with the water twice per run, once with a wig and once with a wig and once with a swim cap over the wig. We hypothesized that if we can pull a head through water with a wig and then with a swim cap over the wig, then we can determine at what length of hair the drag-reduction by the cap over is insignificant. We had to reject our hypothesis because when we pulled the head through the water using a force sensor to measure the difference in forces between the two samples, there was no point at which the hair length became non-significant between the trials with and without the cap. When analyzed, the graphs of the data revealed that there was not a length of hair that was short enough to reduce the drag. The cap trials never had a result that was significant enough to neglect the need for a cap.

Research Done By:

Jeff Hill
Lakeview High School

Adam Stone
Fitzgerald High School