Premium
Dynamic Mode Decomposition for Swirling Jet Flow Undergoing Vortex Breakdown
Author(s) -
Luginsland Tobias,
Kleiser Leonhard
Publication year - 2012
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201210236
Subject(s) - dynamic mode decomposition , vortex , jet (fluid) , mechanics , large eddy simulation , inflow , nozzle , physics , flow (mathematics) , conical surface , turbulence , classical mechanics , geometry , mathematics , thermodynamics
Swirling jets undergoing vortex breakdown occur in many technical applications, e.g. vortex burners, turbines and jet engines. At the stage of vortex breakdown the flow is dominated by a conical shear layer and a large recirculation zone around the jet axis. We performed Large‐Eddy Simulations (LES) of compressible swirling jet flows at Re=5000, Ma=0.6 in the high swirl number regime (S=1). A nozzle is included in our computational setup to account for more realistic inflow conditions. The obtained velocity fields are analyzed by means of temporal and spatial dynamic mode decomposition (DMD) to get further insight into the characteristic structures dominating the flow. We present eigenvalue spectra for the case under consideration and discuss the stability behaviour in time and space. (© 2012 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)