MEASURING THE WAVE DISSIPATION PRODUCED BY A SWIMMING-LINE SEPARATION ROPE

  • Jaina Vilas-Boas
  • D. Silva
  • R. Fernandes
  • P. Gonçalves
  • P. Figueiredo
  • S. Pereira
  • H. Roeseler
  • L. Machado
Keywords: Swimming, hydrodynamics, wave drag

Abstract

Hydrodynamic drag (D) seems to be one of the major determinants of swimming performance. D is usually divided into pressure, friction and wave drag (Dw). Meanwhile, Dw can be due to two distinct phenomena: (i) wave production (Dwwp) and (ii) transfer of negative wave momentum (Dwtm). Dwwp refers to the energy dissipated from the kinetic energy of the swimmer and used to generate waves, and Dwtm refers to the drag effect (reduction of forward kinetic energy of the swimmer) attributed to the impact of waves produced by others, or produced by the swimmer itself and rebounded at a swimming pool wall. In order to define the competition lane of each swimmer, the competition swimming pools dispose of swimming-line separation ropes (S-LSR). In the meantime, the manufacturers of this S-LSR claim that they have the ability to absorb waving energy, and thus to dissipate waves avoiding Dw tm, and other perturbing wave effects. The purpose of this research was to characterize the swimmer’s wave production, and to measure the effect upon the wave energy dissipation of a common S-LSR (Fig.1).