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Effect of Swim Cap Surface Roughness on Passive Drag
Giorgio Gatta1, Matteo Cortesi, Paola Zamparo
11Department for Life Quality Studies, Rimini, School of Pharmacy, Biotechnology and Sport Science, University of Bologna, Bologna, Italy; and 2Department of Neurological, Neuropsychological, Morphological and Movement Sciences, University of Verona, Verona, Italy.
Journal of Strength and Conditioning Research
|May 2, 2015
Summary
Wrinkled swim caps increase drag in swimming, potentially harming performance. Smooth or dimpled caps showed no difference in drag compared to smooth caps, especially when arms are above the head.
Area of Science:
- Sports Science
- Fluid Dynamics
- Biomechanics
Background:
- Technological advancements in swimsuits have improved swimming performance.
- Swim cap technology has lagged behind, despite the head's significant role in hydrodynamics.
- The impact of swim cap surface texture on drag is not well understood.
Purpose of the Study:
- To compare the passive drag (Dp) of three different silicon swim cap models.
- To evaluate the effect of swim cap design (smooth, dimpled, wrinkled) on hydrodynamic drag.
- To assess drag under different swimming conditions (speeds and body positions).
Main Methods:
- Ten swimmers were towed underwater at varying speeds (1.5, 1.7, 1.9 m/s).
- Experiments were conducted in two body positions: arms above head (LA) and arms alongside body (SA).
- Passive drag was measured, and a speed-specific drag coefficient (k) was calculated (k = Dp/v).
Main Results:
- No significant differences in drag (k) were found among swim caps in the LA position.
- In the SA position, no differences in drag were observed between smooth and dimpled caps.
- The wrinkled swim cap showed a significant 4.4% increase in drag (k) compared to the dimpled cap in the SA position.
Conclusions:
- Swim cap surface texture can influence hydrodynamic drag.
- Wrinkled swim caps may be detrimental to swimming performance, particularly in the SA position.
- Further research into swim cap design optimization for reduced drag is warranted.
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