This publication presents an analytical method for the aerodynamic and acoustic pre-design of ducted fans for small aircraft. Based on studies of the primary design variables, the paper discusses the physical sound generation phenomena, as well as the interdisciplinary relationships of ducted fan design. First, the fan design and analysis methods are described. On the basis of an aerodynamic mean line method, the radial distribution of the flow velocities is used to determine the steady blade flow. Unsteady aerodynamic excitations are calculated by means of Sears’ blade response function. To determine the generation and propagation of sound within the ducted fan, Goldstein’s acoustic analogy is solved analytically. The methods are applied to a reference case, for which studies show that ducted fans offer significant potential in reducing sound emission, compared to free propellers. Since the rotor-alone noise of subsonic ducted fans is always cut-off, tonal sound is predominantly excited by rotor–stator interactions. These sources can be significantly reduced by a proper selection of the rotor blade and stator vane numbers, as well as optimal lean and sweep of the stator vanes. Large diameters and axial gaps are acoustically advantageous, but reduce fan stage efficiency and increase nacelle drag due to large wetted areas, especially at cruise. As a result, the importance of considering these complex interdependencies in a comprehensive design approach is shown. The pre-design method presented can be used to determine an optimal ducted fan design, taking into account interdisciplinary trade-offs, with an emphasis on noise. Analysis of the ducted fan concept shows that the ducted fan can be a promising alternative to the free propeller, especially if low noise emission is required.


    Zugriff

    Download


    Exportieren, teilen und zitieren



    Titel :

    Acoustic pre-design studies of ducted fans for small aircraft


    Weitere Titelangaben:

    CEAS Aeronaut J


    Beteiligte:
    Koppelberg, Jan (Autor:in) / Weintraub, Daniel (Autor:in) / Jeschke, Peter (Autor:in)

    Erschienen in:

    CEAS Aeronautical Journal ; 13 , 4 ; 877-889


    Erscheinungsdatum :

    2022-10-01


    Format / Umfang :

    13 pages




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch





    Acoustic pre-design studies of ducted fans for small aircraft

    Koppelberg, Jan / Weintraub, Daniel / Jeschke, Peter | DataCite | 2022


    Aircraft with ducted fans on wings

    ZHOU GUOFU / F ¨ 1 RSTNER MICHAEL / BENDER STEFAN et al. | Europäisches Patentamt | 2023

    Freier Zugriff

    Ducted fans for hybrid electric propulsion of small aircraft

    Weintraub, Daniel / Koppelberg, Jan / Köhler, Jo et al. | Springer Verlag | 2022

    Freier Zugriff

    Ducted fans for hybrid electric propulsion of small aircraft

    Weintraub, Daniel / Koppelberg, Jan / Köhler, Jo Alexander et al. | DataCite | 2022


    VTOL AIRCRAFT WITH LEADING EDGE TILTING DUCTED FANS

    GRONINGA KIRK L / ROBERTSON DANIEL B / LOUIS MATTHEW E | Europäisches Patentamt | 2020

    Freier Zugriff