Journal of Fluid Science and Technology
Online ISSN : 1880-5558
ISSN-L : 1880-5558
Papers
A numerical analysis for identification of flow transition in vortex generation in terms of local flow topology
Katsuyuki NAKAYAMALucas DIAS MIZUSHIMA
著者情報
ジャーナル フリー

2017 年 12 巻 3 号 p. JFST0027

詳細
抄録

A numerical analysis, based on a novel physical quantity of the topology, is presented to specify the key flow leading into a vortex. This analysis traces the flow transition into a vortical flow in terms of local flow geometry (topology) specified by the velocity gradient tensor, and specifies the important flow component for the vortex transition. The transition where a non-vortical flow becomes vortical can be identified by swirlity that represents the unidirectionality and intensity of the azimuthal flow in a plane. The swirl plane after the vortex transition can be predicted by an eigenplane of real eigenvalues of the velocity gradient tensor. Then the tensor components are represented associating with the predicted plane, and their relations to the flow topology are clarified. The analysis of their transitions enables to specify the important flow components that lead the flow into a vortical flow. This numerical analysis can be applied to various turbulent flows in order to clarify the mechanism or feature of the vortex transition, or suppress a specific vortex in engineering fields.

著者関連情報
© 2017 by The Japan Society of Mechanical Engineers
前の記事 次の記事
feedback
Top