Investigation of the structures in the unstable rotating-cone boundary layer

K. Kato, T. Kawata, P. H. Alfredsson, R. J. Lingwood

Research output: Contribution to journalArticle

2 Citations (Scopus)

Abstract

This work reports on the unstable region and the transition process of the boundary-layer flow induced by a rotating cone with a half apex angle of 60 degrees using the probability density function (PDF) contour map of the azimuthal velocity fluctuation, which was first used by Imayama et al. [Phys. Fluids 24, 031701 (2012)PHFLE61070-663110.1063/1.3696020] for the similar boundary-layer flow induced by a rotating disk. The PDF shows that the transition behavior of the rotating-cone flow is similar to that on the rotating disk. The effects of roughness elements on the cone surface have been examined. For the cone with roughnesses, we reconstructed the most probable vortex structure within the boundary layer from the hot-wire anemometry time signals. The results show that the PDF clearly describes the overturning process of the high-momentum upwelling of the spiral vortices, which due to vortex meandering cannot be detected in the phase-averaged velocity field reconstructed from the point measurements. At a late stage of the overturning process, our hot-wire measurements captured high-frequency oscillations, which may be related to secondary instability.

Original languageEnglish
Article number053903
JournalPhysical Review Fluids
Volume4
Issue number5
DOIs
Publication statusPublished - 2019 May
Externally publishedYes

ASJC Scopus subject areas

  • Computational Mechanics
  • Modelling and Simulation
  • Fluid Flow and Transfer Processes

Fingerprint Dive into the research topics of 'Investigation of the structures in the unstable rotating-cone boundary layer'. Together they form a unique fingerprint.

  • Cite this