Abstract Above a critical value of the Reynolds number, flows past bluff bodies are characterized by self-sustained oscillations, due to the formation of the Kármán vortex street. This results in the dynamic loading of the body, which, in practical applications, may lead to structural fatigue. In recent work, it was demonstrated that, in flow past a cylinder, implementing surface hydrophobicity results in decreased drag and lift forces, leading to vortex street cancellation at a critical level of control effort. In order to achieve vortex street suppression at lower levels of control effort, utilizing materials with controllable wettability properties appears as a promising possibility. Thus, in the present work, the effectiveness of a proportional feedback control scheme, utilizing the application of time-dependent slip conditions on the cylinder surface, is investigated by means of CFD simulations. Firstly, the feedback control scheme is tested for a problem definition characterized by the application of slip on the entire cylinder surface, for a wide range of the control scheme parameters; it is demonstrated that flow unsteadiness is reduced at substantially lower levels of control effort, in comparison to corresponding passive control schemes. Secondly, in the frame of feedback control, an optimization problem is formulated and solved, aiming at the partial or full suppression of the Kármán vortex street at a minimal control effort, using time-dependent slip conditions on a part of the cylinder surface. The results demonstrate a further reduction in control effort. Overall, in comparison to passive flow control, a reduction in control effort by two orders of magnitude is attained with the present optimized feedback control scheme.


    Zugriff

    Zugriff prüfen

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Optimal Cancelation of Vortex Street in Flow Past a Circular Cylinder with Controllable Wettability Properties


    Beteiligte:


    Erscheinungsdatum :

    2016-01-01


    Format / Umfang :

    10 pages





    Medientyp :

    Aufsatz/Kapitel (Buch)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Oscillatory rotating flow past a circular cylinder

    Kunka, M. / Foster, M. | AIAA | 1996


    ARTICLE WITH CONTROLLABLE WETTABILITY

    FURRER DAVID ULRICH / BURLATSKY SERGEI F / ELLIOTT PAUL et al. | Europäisches Patentamt | 2017

    Freier Zugriff

    Article with controllable wettability

    FURRER DAVID ULRICH / BURLATSKY SERGEI F / ELLIOTT PAUL et al. | Europäisches Patentamt | 2018

    Freier Zugriff

    Computation of turbulent flow past a circular cylinder

    Ramakrishnan, S / Ota, D / Chakravarthy, S | AIAA | 1995


    Steady flow past a vertical surface-piercing circular cylinder

    Chaplin, J.R. / Teigen, P. | Tema Archiv | 2003