Spectral proper orthogonal decomposition (SPOD) is a major modal analysis that extracts a dominant structure at each frequency from complicated flow data, such as the wavepacket hidden under turbulent jets. This study investigated the physical interpretation of subdominant multilobe structures in the SPOD modes. A high-speed schlieren movie that exhibited multilobe structures in the SPOD was analyzed using a wavelet-based conditional sampling and averaging (WB-CSA) method. The results of WB-CSA showed spatiotemporally localized wavepackets, which were formed intermittently and convected downstream through growth and decay. Such intermittent convection causes multilobe structures in the SPOD, as illustrated by simple synthetic data that model the results of WB-CSA. Therefore, multilobe structures, together with the most dominant single-lobe wavepackets, can be interpreted as representing the intermittent convection of wavepackets.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Interpretation of Multilobe Wavepackets in Spectral Proper Orthogonal Decomposition of Supersonic Jet


    Contributors:

    Published in:

    AIAA Journal ; 60 , 1 ; 56-64


    Publication date :

    2021-08-23


    Size :

    9 pages




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Guide to Spectral Proper Orthogonal Decomposition

    Schmidt, Oliver T. / Colonius, Tim | AIAA | 2020


    Application of Proper Orthogonal Decomposition to a Supersonic Axisymmetric Jet

    E. Caraballo / M. Samimy / J. Scott et al. | AIAA | 2003


    Proper Orthogonal Decomposition Analysis of Numerically Simulated Supersonic Jet flow

    Mignee, Juliette / Kastner, Jeff / Liu, Junhui et al. | AIAA | 2010


    Vortex Buffeting of Aircraft Tail: Interpretation via Proper Orthogonal Decomposition

    Younjong Kim / Donald Rockwell / Antonios Liakopoulos | AIAA | 2005