A variational analysis of flow-reversal condition in a turbulent swirling pipe flow using the bulk-helicity concept

Nobumitsu Yokoi, Akira Yoshizawa, Kimitaka Itoh, Sanae I. Itoh

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The magnitude of axial-flow retardation near the center of a turbulent swirling flow is estimated from the results of the variational analysis with the aid of the helicity concept. It is analytically shown that the axial-flow reversal in a swirl occurs if the bulk helicity imparted to the mean flow exceeds the critical value, which is proportional to the square of the flux. It is suggested that the bulk helicity in the center region plays an important role in determining the flow-reversal condition. Through the comparison with the experimental observations in a turbulent swirling pipe flow, the reliability of the theoretically-derived reversal condition is confirmed.

Original languageEnglish
Pages (from-to)1186-1202
Number of pages17
JournalPhysics of Fluids
Volume16
Issue number5
DOIs
Publication statusPublished - May 2004

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pipe flow
swirling
axial flow

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics

Cite this

A variational analysis of flow-reversal condition in a turbulent swirling pipe flow using the bulk-helicity concept. / Yokoi, Nobumitsu; Yoshizawa, Akira; Itoh, Kimitaka; Itoh, Sanae I.

In: Physics of Fluids, Vol. 16, No. 5, 05.2004, p. 1186-1202.

Research output: Contribution to journalArticle

Yokoi, Nobumitsu ; Yoshizawa, Akira ; Itoh, Kimitaka ; Itoh, Sanae I. / A variational analysis of flow-reversal condition in a turbulent swirling pipe flow using the bulk-helicity concept. In: Physics of Fluids. 2004 ; Vol. 16, No. 5. pp. 1186-1202.
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