Flow Structures Identification through Proper Orthogonal Decomposition: The Flow around Two Distinct Cylinders

• Type: Article in International Scientific Journal
• Date: 2021

Authors

Ângela M. Ribau (Author) Other; Nelson D. Gonçalves (Author) Other; Luís L. Ferrás (Author) Other; Alexandre M. Afonso (Author) FEUP; A. M. Ribau (Author) FEUP

Journal

The Journal is awaiting validation by the Administrative Services.

Title: FLUIDS

Vol. 127

Pages: 1-384

ISSN: 2311-5521

Indexing

ISI Web of Knowledge - 6 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00V-M8X

DOI: 10.3390/fluids6110384

Abstract (EN): Numerical simulations of fluid flows can produce a huge amount of data and inadvertently important flow structures can be ignored, if a thorough analysis is not performed. The identification of these flow structures, mainly in transient situations, is a complex task, since such structures change in time and can move along the domain. With the decomposition of the entire data set into smaller sets, important structures present in the main flow and structures with periodic behaviour, like vortices, can be identified. Therefore, through the analysis of the frequency of each of these components and using a smaller number of components, we show that the Proper Orthogonal Decomposition can be used not only to reduce the amount of significant data, but also to obtain a better and global understanding of the flow (through the analysis of specific modes). In this work, the von Karman vortex street is decomposed into a generator base and analysed through the Proper Orthogonal Decomposition for the 2D flow around a cylinder and the 2D flow around two cylinders with different radii. We consider a Newtonian fluid and two non-Newtonian power-law fluids, with n=0.7 and n=1.3. Grouping specific modes, a reconstruction is made, allowing the identification of complex structures that otherwise would be impossible to identify using simple post-processing of the fluid flow.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 20