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UNSTEADY DRAG ON A CYLINDER DUE TO TRANSVERSE OSCILLATION AT FINITE AMPLITUDE

✍ Scribed by C.L. MORFEY; M. TAN


Publisher
Elsevier Science
Year
2001
Tongue
English
Weight
354 KB
Volume
246
Category
Article
ISSN
0022-460X

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✦ Synopsis


Transverse oscillations of a cylinder in a viscous #uid generate a force on the #uid that becomes non-linear at large oscillation amplitudes. When the cylinder motion is sinusoidal, non-linearity produces odd order harmonic distortion in the force. Numerical simulations based on the incompressible Navier}Stokes equations are used to explore (1) departures from linear theory and (2) the approach to quasi-steady behaviour, for oscillations over a wide frequency range at peak Reynolds numbers between 10\ and 10. Non-linearity appears once the displacement amplitude becomes comparable with the viscous penetration depth at the oscillation frequency. The results provide insight into the attenuation of sound in air-"lled "brous materials, where non-linear behaviour has been observed at sound pressure levels around 150 dB and upwards (see the paper by H.