A thermoacoustic interpretation of Mack’s second-mode instability is proposed. It is demonstrated that the fundamental mechanism of second-mode wave growth in hypersonic boundary layers is consistent with standing-wave thermoacoustically driven instability. The resonant nature of such modes is sustained by an acoustic impedance well between the wall (infinite impedance) and near the sonic line (secondary peak in impedance). A Lagrangian approach is adopted to show that such resonant standing waves derive energy from the base flow through thermoacoustic Reynolds stress, which results from the divergence of acoustic power inside the impedance well, and thermodynamic work. This treatment does not represent a complete energy closure (due to the neglect of viscosity), but it does provide insight toward a fundamental energy source and the physical mechanisms governing Mack’s acoustic second mode.


    Access

    Download


    Export, share and cite



    Title :

    Thermoacoustic Interpretation of Second-Mode Instability


    Contributors:

    Published in:

    AIAA Journal ; 56 , 9 ; 3585-3592


    Publication date :

    2018-09-01




    Type of media :

    Article (Journal)


    Type of material :

    Electronic Resource


    Language :

    English




    Thermoacoustic Flow Instability in a Scramjet Combustor

    Ma, Fuhua / Li, Jian / Yang, Vigor et al. | AIAA | 2005


    Chaotic and Linear Statistics Analysis in Thermoacoustic Instability Detection

    Chiocchini, S. / Pagliaroli, T. / Camussi, R. et al. | AIAA | 2018




    Experimental Study on Thermoacoustic Instability in a Rijke Tube

    Yang, Y. / Wang, W. | British Library Online Contents | 2014