Wall-induced forces on a rigid sphere at finite Reynolds number

Zeng, Lanying; Balachandar, S.; Fischer, Paul

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https://hdl.handle.net/2142/986 Copy

Description

Title

Wall-induced forces on a rigid sphere at finite Reynolds number

Author(s)

• Zeng, Lanying
• Balachandar, S.
• Fischer, Paul

Issue Date

2005

Keyword(s)

Fluid mechanics

Abstract

We perform direct numerical simulations of a rigid sphere translating parallel to a flat wall in an otherwise quiescent ambient fluid. A spectral element method is employed to perform the simulations with high accuracy. For Re<100, we observe the lift coefficient to decrease with both Reynolds number and distance from the wall. In this regime the present results are in good agreement with the low-Reynoldsnumber theory of Vasseur & Cox (1977), with the recent experiments of Takemura & Magnaudet (2003) and with the simulations of Kim et al. (1993). The most surprising result from the present simulations is that the wall-induced lift coefficient increases dramatically with increasing Re above about 100. Detailed analysis of the flow field around the sphere suggests that this increase is due to an imperfect bifurcation resulting in the formation of a double-threaded wake vortical structure. In addition to a non-rotating sphere, we also simulate a freely rotating sphere in order to assess the importance of free rotation on the translational motion of the sphere. We observe the effect of sphere rotation on lift and drag forces to be small. We also explore the effect of the wall on the onset of unsteadiness.

Publisher

Cambridge University Press

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/986

DOI

https://doi.org/10.1017/S0022112005004738

Has Version(s)

Previously released as TAM Report 1049. http://hdl.handle.net/2142/245.

Copyright and License Information

Copyright owned by Cambridge University Press 2005.

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