Decomposition of time-resolved tomographic PIV

• Published in: Experiments in fluids Vol. 52; no. 6; pp. 1567 - 1579
• Main Authors: Schmid, Peter J., Violato, Daniele, Scarano, Fulvio
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2012; Springer; Springer Verlag (Germany)
• Subjects: Coherence; Decomposition; Dynamics; Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics; Exact sciences and technology; Fluid dynamics; Fluid flow; Fluid- and Aerodynamics; Fluids; Fundamental areas of phenomenology (including applications); Heat and Mass Transfer; Instrumentation for fluid dynamics; Jets; Particle image velocimetry; Physics; Research Article; Temporal logic; Transition to turbulence; Turbulent flows, convection, and heat transfer; Vortex Ring; Dynamic Mode Decomposition; Proper Orthogonal Decomposition; Proper Orthogonal Decomposition Mode; Strouhal Number; Water; Test facilities; Three dimensional flow; Circular jet; Tomography; Ring vortex; Particle image velocimetry; Transition flow; Experimental study; Velocity measurement; Vortex pair; Turbulent laminar transition
• ISSN: 0723-4864; 1432-1114
• DOI: 10.1007/s00348-012-1266-8

An experimental study has been conducted on a transitional water jet at a Reynolds number of Re  = 5,000. Flow fields have been obtained by means of time-resolved tomographic particle image velocimetry capturing all relevant spatial and temporal scales. The measured three-dimensional flow fields have then been postprocessed by the dynamic mode decomposition which identifies coherent structures that contribute significantly to the dynamics of the jet. Both temporal and spatial analyses have been performed. Where the jet exhibits a primary axisymmetric instability followed by a pairing of the vortex rings, dominant dynamic modes have been extracted together with their amplitude distribution. These modes represent a basis for the low-dimensional description of the dominant flow features.