Military aircraft employ aero-gas turbines fitted with afterburners to meet the requirements of rapid increase in thrust for flight operations that involve combat maneuvers. The airflow rate through an aero-gas turbine remains unchanged even after an afterburner is invoked to ensure that there is no disruption in the turbomachinery operating characteristics. Triggering of flow instabilities leading, in turn, to combustor instabilities could occur due to the incorrect Rayleigh heat addition in the constant area afterburner. In normal operation, the propelling nozzle should be correctly opened up to pass the increased volumetric flow rate of the heated air due to heat addition in the afterburner. Any mismatch could result in violent flow instabilities including possible fan stall in a turbofan. The processes of triggering instabilities by sub/supercritical Rayleigh heat addition have been characterized. The gas dynamic equivalence of secondary mass addition to heat addition has been analyzed and experimentally validated in a model afterburner combustion test rig. Consequently, sudden sub/supercritical heat addition in an afterburner with its corresponding propelling nozzle closure has been studied and characterized for the equivalent mass addition in a separate model afterburner simulation test rig.


    Access

    Check access

    Check availability in my library

    Order at Subito €


    Export, share and cite



    Title :

    Triggering of Flow Instabilities by Simulated Sub/Supercritical Rayleigh Heat Addition in an Aero-Gas Turbine Afterburner


    Additional title:

    Lect.Notes Mechanical Engineering




    Publication date :

    2020-08-01


    Size :

    13 pages





    Type of media :

    Article/Chapter (Book)


    Type of material :

    Electronic Resource


    Language :

    English




    IMECE2005-79874 Flow Investigations in an Aero Gas Turbine Engine Afterburner

    Kumar, S. S. / Ganesan, V. / American Society of Mechanical Engineers | British Library Conference Proceedings | 2005


    Simulation studies on an aero engine afterburner control system

    Kathiresan, S. / Garudachar, B. K. / Balakrishnan, S. R. et al. | British Library Conference Proceedings | 2000