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ARTICLE

Numerical Simulations of Unstable Flow through a Spherical Bulge in a 90-degree Asymmetrical Bend

by ,

1 Instituto Superior T ´ecnico, Technical University of Lisbon, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.

Computer Modeling in Engineering & Sciences 2005, 9(2), 211-220. https://doi.org/10.3970/cmes.2005.009.211

Abstract

Time-dependent numerical simulations of the flow through a spherical bulge in a 90-degree asymmetrical bend have been performed for Reynolds numbers in the range 100-400. The present results have demonstrated that the flow reaches asymptotically steady, symmetrical solutions for Reynolds numbers up to 300, whereas a value of 400 for this parameter leads to unsteadiness. The computed flow behavior at this higher Reynolds number has shown to be characterized by an intermittent transition between small-amplitude, irregular oscillations and large-amplitude bursts occurring at a low frequency. In addition, the unsteady flow was asymmetrical and exhibited swirl switching.

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Keywords

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