Steady hydrodynamic interaction between human swimmers
Related Experiment Video
Updated: Jan 26, 2026

A Rapidly Incremented Tethered-Swimming Maximal Protocol for Cardiorespiratory Assessment of Swimmers
Published on: January 28, 2020
Zhi-Ming Yuan1,2, Mingxin Li2, Chun-Yan Ji1
11 School of Naval Architecture and Ocean Engineering, Jiangsu University of Science and Technology , Zhenjiang, Jiangsu 212003 , People's Republic of China.
Abstract:
This study focuses on the hydrodynamic interaction between two or three human swimmers in competitive swimming. Although the swimming performance of a single swimmer has been widely examined, studies on the interaction between multiple competitive swimmers are very rare. Experiments showed evidence that the drag of a swimmer could be modified by the existence of the other adjacent competitors (Chatard & Wilson. 2003 Med. Sci. Sports Exerc. 35, 1176-1181. ( doi:10.1249/01.MSS.0000074564.06106.1F )). The following questions arise: (1) what mechanism determines the interaction; (2) which position experiences drag reduction or drag increase; (3) how much can drag be reduced or increased in a formation? According to the authors' knowledge, such questions have not been addressed by any published literature. Therefore, the main purpose of this study is to find the mechanism of the hydrodynamic interaction between human swimmers and to quantify this interactive effect by using a steady potential flow solver. The free-surface effect was fully taken into account in our calculations. We firstly calculated the wave drag of a swimmer swimming solely in an open swimming pool. Then we calculated the wave drag of the same swimmer when he/she swam in the wake region of one or two leading swimmers. The results showed that the hydrodynamic interaction made a significant contribution to the drafter's wave drag. By following a leading swimmer, a drafter at wave-riding positions could save up to 63% of their wave drag at speed of 2.0 m s-1 and lateral separation of 2.0 m. Particularly, when a drafter is following two side-by-side leaders, the drag reduction could even be doubled. To the authors' knowledge, this study is the first to demonstrate that the hydrodynamic interaction between human swimmers can best be described and explained in terms of wave interference effect on the free water surface. When the wave cancellation effect is observed, the wave drag of a drafter could be minimized, and this wave cancellation effect can be achieved only when the drafter is in a wave-riding position.
Related Concept Videos
Steady State Concentration
Most drugs are administered in repeated doses at fixed intervals or through continuous...
Steady Flow of a Fluid Stream
During this process, the momentum of the fluid within the control volume remains constant over the time interval dt. By applying the...
Transient and Steady-state Response
These test signals are integral in designing control systems to exhibit two key performance aspects: transient response and steady-state...
Velocity and Acceleration in Steady and Unsteady Flow
The acceleration can be generalized to any point in the flow, and expressed as components along three perpendicular directions, representing changes in velocity over...
Steady, Laminar Flow Between Parallel Plates
Steady, Laminar Flow in Circular Tubes

