Propelling Efficiency, Water Resistances, and the Latest in Young Swimmer’s Biomechanics

2020 ◽  
pp. 151-170
Author(s):  
Tiago M. Barbosa ◽  
Jorge E. Morais
Keyword(s):  
Propelling Efficiency

The interplay between propelling efficiency, hydrodynamic position and energy cost of front crawl in 8 to 19-year-old swimmers

2008 ◽  
Vol 104 (4) ◽  
pp. 689-699 ◽  
Author(s):  
P. Zamparo ◽  
S. Lazzer ◽  
C. Antoniazzi ◽  
S. Cedolin ◽  
R. Avon ◽  
...  
Keyword(s):  
Energy Cost ◽  
Front Crawl ◽  
Propelling Efficiency

Propelling efficiency of front-crawl swimming

1988 ◽  
Vol 65 (6) ◽  
pp. 2506-2512 ◽  
Author(s):  
H. M. Toussaint ◽  
A. Beelen ◽  
A. Rodenburg ◽  
A. J. Sargeant ◽  
G. de Groot ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Energy Expenditure ◽  
Mechanical Efficiency ◽  
Total Efficiency ◽  
Extended Version ◽  
O2 Uptake ◽  
Free Swimming ◽  
Front Crawl ◽  
Propelling Efficiency ◽  
The Relationship

In this study the propelling efficiency (ep) of front-crawl swimming, by use of the arms only, was calculated in four subjects. This is the ratio of the power used to overcome drag (Pd) to the total mechanical power (Po) produced including power wasted in changing the kinetic energy of masses of water (Pk). By the use of an extended version of the system to measure active drag (MAD system), Pd was measured directly. Simultaneous measurement of O2 uptake (VO2) enabled the establishment of the relationship between the rate of the energy expenditure (PVO2) and Po (since when swimming on the MAD system Po = Pd). These individual relationships describing the mechanical efficiency (8-12%) were then used to estimate Po in free swimming from measurements of VO2. Because Pd was directly measured at each velocity studied by use of the MAD system, ep could be calculated according to the equation ep = Pd/(Pd + Pk) = Pd/Po. For the four top class swimmers studied, ep was found to range from 46 to 77%. Total efficiency, defined as the product of mechanical and propelling efficiency, ranged from 5 to 8%.

Mechanical and propelling efficiency in swimming derived from exercise using a laboratory-based whole-body swimming ergometer

2012 ◽  
Vol 113 (4) ◽  
pp. 584-594 ◽  
Author(s):  
Paola Zamparo ◽  
Ian L. Swaine
Keyword(s):  
Power Output ◽  
Power Input ◽  
Mechanical Power ◽  
Whole Body ◽  
Metabolic Power ◽  
Exact Simulation ◽  
Mechanical Power Output ◽  
Propelling Efficiency ◽  
Overall Efficiency ◽  
Active Drag

Determining the efficiency of a swimming stroke is difficult because different “efficiencies” can be computed based on the partitioning of mechanical power output (Ẇ) into its useful and nonuseful components, as well as because of the difficulties in measuring the forces that a swimmer can exert in water. In this paper, overall efficiency (ηO = ẆTOT/Ė, where ẆTOT is total mechanical power output, and Ė is overall metabolic power input) was calculated in 10 swimmers by means of a laboratory-based whole-body swimming ergometer, whereas propelling efficiency (ηP = ẆD/ẆTOT, where ẆD is the power to overcome drag) was estimated based on these values and on values of drag efficiency (ηD = ẆD/Ė): ηP = ηD/ηO. The values of ηD reported in the literature range from 0.03 to 0.09 (based on data for passive and active drag, respectively). ηO was 0.28 ± 0.01, and ηP was estimated to range from ∼0.10 (ηD = 0.03) to 0.35 (ηD = 0.09). Even if there are obvious limitations to exact simulation of the whole swimming stroke within the laboratory, these calculations suggest that the data reported in the literature for ηO are probably underestimated, because not all components of ẆTOT can be measured accurately in this environment. Similarly, our estimations of ηP suggest that the data reported in the literature are probably overestimated.

The interplay between arms-only propelling efficiency, power output and speed in master swimmers

2014 ◽  
Vol 114 (6) ◽  
pp. 1259-1268 ◽  
Author(s):  
P. Zamparo ◽  
E. Turri ◽  
R. Peterson Silveira ◽  
A. Poli
Keyword(s):  
Power Output ◽  
Propelling Efficiency

Air-levitated platelets: from take off to motion

2017 ◽  
Vol 814 ◽  
pp. 535-546 ◽  
Author(s):  
Dan Soto ◽  
Hélène de Maleprade ◽  
Christophe Clanet ◽  
David Quéré
Keyword(s):  
Porous Surface ◽  
Porous Substrate ◽  
Propelling Efficiency ◽  
Directional Motion ◽  
Texture Design

A plate placed above a porous substrate through which air is blown can levitate if the airflow is strong enough. We first model the flow needed for taking off, and then examine how an asymmetric texture etched on the porous surface induces directional motion of the hovercraft. We discuss how the texture design impacts the propelling efficiency, and how it can be used to manipulate these frictionless objects both in translation and in rotation.

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