Numerical and experimental investigations of human swimming motions

Abstract

This paper reviews unsteady flow conditions in human swimming and identifies the limitations and future potential of the current methods of analysing unsteady flow. The capability of computational fluid dynamics (CFD) has been extended from approaches assuming steady-state conditions to consideration of unsteady/transient conditions associated with the body motion of a swimmer. However, to predict hydrodynamic forces and the swimmer’s potential speeds accurately, more robust and efficient numerical methods are necessary, coupled with validation procedures, requiring detailed experimental data reflecting local flow. Experimental data obtained by particle image velocimetry (PIV) in this area are limited, because at present observations are restricted to a two-dimensional 1.0 m2 area, though this could be improved if the output range of the associated laser sheet increased. Simulations of human swimming are expected to improve competitive swimming, and our review has identified two important advances relating to understanding the flow conditions affecting performance in front crawl swimming: one is a mechanism for generating unsteady fluid forces, and the other is a theory relating to increased speed and efficiency.

Individual–Environment Interactions in Swimming: The Smallest Unit for Analysing the Emergence of Coordination Dynamics in Performance?

“…Numerous methods have been designed to understand how purposive human movement might perturb fluids (for reviews, see [55] and [56]), ranging from experiments (i.e. tufts methods) to robotics and mathematical modelling.…”

“…In both approaches, the motion resulted in the production of vortices [4], similar to those previously observed [59] when the hand adapted its orientation. An important advantage of PIV is that it does not disturb the swimmer's actions [55] in experiments. However, this method needs further investigation since current studies are limited by issues of transfer to competitive swimming conditions (i.e.…”

“…flumes, fins and paddles) to gain a general and indirect (i.e. artificial) overview of this coupling [55]. Ecological dynamics offers a new perspective for assessing these functional interactions, requiring investigators to manipulate swimmers' actions and/or flow dynamics to measure the impact on the performer-environment system.…”

Assessment of passive drag in swimming by numerical simulation and analytical procedure

“…To learn about swimmer's passive drag, literature reports three different approaches (Barbosa et al, 2015;Takagi, Nakashima, Sato, Matsuuchi, & Sanders, 2015): (1) experimental techniques (towing and gliding tests), (2) numerical simulations (computer fluid dynamics [CFD]) and (3) analytical procedures (a set of mathematical models encompassed by Naval Architecture but adapted to human swimming, followed by use of the drag equation). Eventually, researchers started to investigate whether the different approaches would return the same results (i.e., goodness-of-fit), if they were sensitive enough to reflect the same phenomenon or not.…”

Realization and swimming performance of the breaststroke by a swimming humanoid robot

“…First, it is expected that it will become an experimental platform for the research of human swimming. To date, many simulation studies about human swimming have been conducted [12][13][14][15]. Such simulation technique is very useful and powerful tool for analysis.…”