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Peristaltic transport of a fractional Burgers’ fluid with variable viscosity through an inclined tube

100%

Rachid H.

Open Physics

2015

vol. 13

issue 1

In the present study,we investigate the unsteady peristaltic transport of a viscoelastic fluid with fractional Burgers’ model in an inclined tube. We suppose that the viscosity is variable in the radial direction. This analysis has been carried out under low Reynolds number and long-wavelength approximations. An analytical solution to the problem is obtained using a fractional calculus approach. Figures are plotted to show the effects of angle of inclination, Reynolds number, Froude number, material constants, fractional parameters, parameter of viscosity and amplitude ratio on the pressure gradient, pressure rise, friction force, axial velocity and on the mechanical efficiency.

Mechanical Work and Long-Distance Performance Prediction: the Influence of Allometric Scaling

94%

Peikriszwili Tartaruga M., Brisswalter J., Mota C. B., Alberton C. L., Gomeñuka N. A., Peyré-Tartaruga L. A.

Journal of Human Kinetics

2013

vol. 38

73-82

The purpose of this study was to examine the effect of allometric scaling on the relationship between mechanical work and long-distance running performance in recreational runners. Fourteen recreational long-distance runners (male, mean ± SD - age: 29 ± 7 years; body mass: 70.0 ± 10.2 kg; body height: 1.71 ± 0.07 m; maximal oxygen uptake: VO2max 52.0 ± 4.9 ml·kg-1·min-1) performed two tests: a continuous incremental test to volitional exhaustion in order to determine VO2max, and a 6-minute running submaximal test at 3.1 m·s-1, during which segments in the sagittal plane were recorded using a digital camera and the internal (Wint), external (Wext) and total (Wtot) mechanic work, in J.kg-1·m-1, was subsequently calculated. The results indicated a significant correlation between mechanical work and performance, however, the strongest correlations were observed when allometric exponents were used (respectively for Wint, Wext and Wtot; non allometric vs. allometric scaling defined by literature (0.75) or determined mathematically (0.49): r = 0.38 vs. r = 0.44 and r = 0.50; r = 0.80 vs. r = 0.83 and r = 0.82; r = 0.70 vs. r = 0.77 and r = 0.78). These results indicate that mechanical work could be used as a predictor of recreational long-distance performance and an allometric model may improve this prediction.

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1 Journal of Human Kinetics

1 Open Physics

1 2015

1 2013

1 Alberton C. L.

1 Brisswalter J.

1 Gomeñuka N. A.

1 Mota C. B.

1 Peikriszwili Tartaruga M.

1 Peyré-Tartaruga L. A.

1 Rachid H.

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Peristaltic transport of a fractional Burgers’ fluid with variable viscosity through an inclined tube

Mechanical Work and Long-Distance Performance Prediction: the Influence of Allometric Scaling