title: 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 m(2) 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.
authors.affiliation: a Faculty of Health and Sport Sciences , University of Tsukuba , Tsukuba , Ibaraki , Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Takagi
authors.affiliation: b Department of Mechanical and Control Engineering , Tokyo Institute of Technology , Tokyo , Japan.
authors.forename: Motomu
authors.initials: M
authors.lastname: Nakashima
authors.affiliation: c Nuclear Energy and Safety , Paul Scherrer Institute , Villigen , Switzerland.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Sato
authors.affiliation: d Emeritus Professor, University of Tsukuba , Tsukuba , Ibaraki , Japan.
authors.forename: Kazuo
authors.initials: K
authors.lastname: Matsuuchi
authors.affiliation: e Exercise and Sport Science , The University of Sydney , Sydney , Australia.
authors.forename: Ross H
authors.initials: RH
authors.lastname: Sanders
mesh_terms: D001132:Arm / Q000502:physiology; D001696:Biomechanical Phenomena; D003163:Competitive Behavior / Q000502:physiology; D003198:Computer Simulation; D006225:Hand / Q000502:physiology; D006801:Humans; D057446:Hydrodynamics; D008954:Models, Biological; D009068:Movement / Q000502:physiology*; D012212:Rheology; D012371:Robotics; D013550:Swimming / Q000502:physiology*
keywords: Computational fluid dynamics; particle image velocimetry; pressure distribution; robot; swimming simulation model; unsteady fluid force