Roughness trips are widely applied in wind-tunnel testing to hasten the laminar–turbulent boundary-layer transition. It is well known that they influence the boundary-layer transition and its development. However, their influence on aeroacoustic quantities (in particular, on the airfoil trailing-edge noise) is not yet fully understood. This paper discusses the relationship between the trip height and the boundary-layer development and radiated trailing-edge noise. Wind-tunnel experiments were performed with zigzag strips and grit elements placed on the surface of a NACA 0012 airfoil. The roughness trip heights k ranged from 17 to 214% of the undisturbed boundary-layer thickness δ k at the trip location. The chord-based Reynolds number varied from 1.3 × 10 5 to 3.3 × 10 5 . This paper shows that trip heights within 50 to 105% of δ k have little influence on the near field and the trailing-edge noise. However, trips with k / δ k > 1.05 increase the spectra of velocity and pressure fluctuations in the low-frequency range up to 2.5 and 3 dB, respectively, resulting in an increase of the trailing-edge radiated noise up to 4 dB in a similar frequency range. In summary, this paper shows the importance of carefully defining the roughness trip used to trigger a laminar–turbulent transition in aeroacoustic and aerodynamic measurements.


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    Titel :

    Influence of Roughness Trips on Near- and Far-Field Trailing-Edge Noise



    Erschienen in:

    AIAA Journal ; 60 , 10 ; 5880-5889


    Erscheinungsdatum :

    01.10.2022




    Medientyp :

    Aufsatz (Konferenz) , Aufsatz (Zeitschrift)


    Format :

    Elektronische Ressource


    Sprache :

    Englisch




    Near Field Trailing Edge Tone Noise Computation

    Loh, C. Y. / AIAA | British Library Conference Proceedings | 2003



    Influence of Surface Roughness Geometry on Trailing Edge Wall Pressure Fluctuations and Noise

    dos Santos, Fernanda Leticia / Even, Nikolaj A. / Botero, Laura et al. | AIAA | 2021


    Trailing Edge Noise

    Strahle, Warren C. / Nagamatsu, Henry T. / Schwartz, Ira R. | AIAA | 1976


    Trailing edge noise

    TAM, C. / YU, J. | AIAA | 1975