A modified extremum-seeking closed-loop control system is proposed for jet mixing enhancement. The system introduces a variable perturbation component that may act to adjust adaptively the searching range of the optimal control signal. The actuator is a single pulsed minijet injected radially into the main jet before its issue. The excitation frequency f e for the minjet is controlled by an electromagnetic valve. The open-loop control measurements indicate that, given the duty cycle and the mass flow rate ratio of the minijet to the main jet, the decay rate K of jet centerline mean velocity, which provides a measure for jet mixing, displays a maximum at the optimum frequency ratio f e / f 0 = 0.5 , where f 0 is the preferred-mode frequency of the main jet. Comparison is made between the modified and classical systems. Although both may find automatically the optimal f e / f 0 and hence a maximum K , the modified system achieves a contraction in the fluctuating f e , when the control target is reached, by 70%, and subsequently an increase in K by 12%. The new system further exhibits a better robustness than the classical.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Modified Extremum-Seeking Closed-Loop System for Jet Mixing Enhancement


    Beteiligte:
    Fan, D. W. (Autor:in) / Wu, Z. (Autor:in) / Yang, H. (Autor:in) / Li, J. D. (Autor:in) / Zhou, Y. (Autor:in)

    Erschienen in:

    AIAA Journal ; 55 , 11 ; 3891-3902


    Erscheinungsdatum :

    2017-07-06


    Format / Umfang :

    12 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch