BROWSE

Related Researcher

Author's Photo

Kim, Jooha
Fluid-Based Convergence Lab (FBC)
Research Interests
  • Experimental fluid mechanics
  • Flow control
  • Flow visualization

ITEM VIEW & DOWNLOAD

Inverse Magnus effect on a rotating sphere: when and why

Cited 0 times inthomson ciCited 0 times inthomson ci
Title
Inverse Magnus effect on a rotating sphere: when and why
Author
Kim, JoohaChoi, HaecheonPark, HyungminYoo, Jung Yul
Keywords
separated flows; wakes/jets
Issue Date
2014-08
Publisher
CAMBRIDGE UNIV PRESS
Citation
JOURNAL OF FLUID MECHANICS, v.754, no., pp.R2-1 - R2-11
Abstract
In some specific conditions, a flying spinning ball deflects in a direction opposite to that predicted by the Magnus effect, which is known as the inverse Magnus effect. To elucidate when and why this effect occurs, we measure the variations of the drag and lift forces on a rotating sphere and the corresponding flow field with the spin ratio (the ratio of the rotational velocity to the translational one). This counterintuitive phenomenon occurs because the boundary layer flow moving against the surface of a rotating sphere undergoes a transition to turbulence, whereas that moving with the rotating surface remains laminar. The turbulence energizes the flow and thus the main separation occurs farther downstream, inducing faster flow velocity there and generating negative lift force. Empirical formulae are derived to predict the location where the flow separates as a function of the Reynolds number and the spin ratio. Using the formulae derived, the condition for the onset of the inverse Magnus effect is suggested based on the negative lift generation mechanism.
URI
Go to Link
DOI
10.1017/jfm.2014.428
ISSN
0022-1120
Appears in Collections:
MEN_Journal Papers
Files in This Item:
Kim et al. (2014).pdf Download

find_unist can give you direct access to the published full text of this article. (UNISTARs only)

Show full item record

qrcode

  • mendeley

    citeulike

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

MENU