In the interaction of an acoustic field with a moving airframe, a canonical initial value problem for an acoustic field induced by an unsteady source distribution q(t,x) with q=0 for t<=0, in a medium moving with a uniform unsteady velocity U(t).i in the coordinate system x fixed on the airframe, is encountered. Signals issued from a source point S in the domain of dependence 'D' of an observation point P at time t will arrive at point P more than once corresponding to different retarded times 'tau' in the interval (0,t). The number of arrivals is called the multiplicity of the point S. The multiplicity equals one if the velocity U remains subsonic and can be greater when U becomes supersonic. For an unsteady uniform flow U(t).i, rules are formulated for defining the smallest number of I subdomains Vi of 'D' with the union of Vi equal to 'D'. Each subdomain has multiplicity 1 and a formula for the corresponding retarded time. The number of subdomains Vi with nonempty intersection is the multiplicity m of the intersection. The multiplicity is at most I. Examples demonstrating these rules are presented for media at accelerating and/or decelerating supersonic speed.


    Zugriff

    Zugriff über TIB

    Verfügbarkeit in meiner Bibliothek prüfen

    Bestellung bei Subito €


    Exportieren, teilen und zitieren



    Titel :

    Acoustic field in unsteady moving media


    Weitere Titelangaben:

    Akustische Felder in sich instationär bewegenden Medien


    Beteiligte:
    Bauer, F. (Autor:in) / Maestrello, L. (Autor:in) / Ting, L. (Autor:in)

    Erschienen in:

    Erscheinungsdatum :

    1996


    Format / Umfang :

    15 Seiten, 10 Bilder, 6 Quellen




    Medientyp :

    Aufsatz (Zeitschrift)


    Format :

    Print


    Sprache :

    Englisch




    Moving wall effects in unsteady flow

    ERICSSON, L. E. | AIAA | 1988


    Kinetic meshless methods for unsteady moving boundaries

    Ramesh, V. / Vivek, S. / Deshpande, S.M. | Tema Archiv | 2010


    Moving-Wall Effect on Unsteady Boundary Layers

    H. Dumitrescu / V. Cardos | AIAA | 2000


    Unsteady Aerodynamics of Fast Moving Control Surfaces

    W. Kolander / H. Hansen | NTIS | 1984


    An Acoustic Analogy Formulation for Uniformly Moving Media: Formulation 1C

    Najafi-Yazdi, Alireza / Mongeau, Luc / Bres, Guillaume | AIAA | 2010