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Journal of Flow Visualization and Image Processing

ISSN for PRINT: 1065-3090

Institutional price:	$586.00
Issues per year:	4

Best Paper Award Selection - Editorial Board Site

2003, Volume10

162 pages

DOI: 10.1615/JFlowVisImageProc.v10.i12

Issue price - $280.00

ON THE BEHAVIOR OF POD MODES OF THE FLOW PAST A PERFORATED PLATE

Giancarlo Alfonsi
CESIC — Supercomputing Center for Computational Engineering, Fluid Dynamics Division, Università della Calabria, Via P. Bucci 22b, 87036 Rende (Cosenza), Italy

Leonardo Primavera
CESIC — Supercomputing Center for Computational Engineering, Fluid Dynamics Division, Università della Calabria, Via P. Bucci 22b, 87036 Rende (Cosenza), Italy

Riccardo Felisari
Dipartimento di Ingegneria Idraulica, Politecnico di Milano Piazza L. da Vinci 32, 20133 Milano, Italy

ABSTRACT

The temporal behavior of coherent structures of turbulence in the case of a multiple interacting turbulent jet flow developing downstream from a perforated plate is investigated. The Proper Orthogonal Decomposition (POD) is applied to extract the coherent motions from a turbulent flow database of numerical nature obtained with the use of a finite-element computational code for the numerical integration of the Navier–Stokes equations at Re = 13300; for turbulence modeling the Large Eddy Simulation (LES) approach is followed and the Smagorinsky Sub Grid-Scale model (SGS) is used. The three-dimensional time-dependent velocity field past the perforated plate is computed and 400 time steps of the turbulent statistically steady state are considered for the decomposition of the flow field onto two appropriate computational subdomains. "Reduced" velocity fields, each reflecting the contribution of the first four most energetic POD modes containing up to 96.24% and 95.82% of the turbulent kinetic energy of the originary flow field, respectively, are reconstructed. Results are presented in terms of temporal evolution of the turbulent kinetic energy of the four most energetic eigenmodes of each subdomain, showing, in both cases, a rather regular temporal dynamics of the coherent structures (the POD modes) through different phases of the turbulent activity.