The delay of turbulent boundary layer separation by oscillatory active control

Y. Katz, D. Nishri, Israel J Wygnanski

Research output: Chapter in Book/Report/Conference proceedingConference contribution

9 Citations (Scopus)

Abstract

The flow over a solid wedge from which a fully developed, turbulent boundary layer separates naturally, was investigated experimentally. The flow which separates at the geometric discontinuity turnes into a free mixing layer downstream of it. However the flow can be forced to reattach by the introduction of two-dimensional, harmonic, and small-amplitude perturbations at the apex of the wedge. The temporally-averaged characteristics of the reattached boundary layer are typical to flows at less severe pressure gradients, with the exception of the spanwise coherence near the solid surface which has been notably enhanced by the imposed perturbations. Phase-locked and ensemble-averaged results indicate that the subharmonic frequency dominates the flow at large distances from the apex at all forcing frequencies considered thus far. The preliminary results presented, indicate that this might be an effective way to delay separation of turbulent as well as laminar boundary layers.

Original languageEnglish (US)
Title of host publicationAIAA 2nd Shear Flow Conference, 1989
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
StatePublished - 1989
EventAIAA 2nd Shear Flow Conference, 1989 - Tempe, United States
Duration: Mar 13 1989Mar 16 1989

Other

OtherAIAA 2nd Shear Flow Conference, 1989
CountryUnited States
CityTempe
Period3/13/893/16/89

Fingerprint

Boundary layers
Laminar boundary layer
Pressure gradient

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Katz, Y., Nishri, D., & Wygnanski, I. J. (1989). The delay of turbulent boundary layer separation by oscillatory active control. In AIAA 2nd Shear Flow Conference, 1989 [AIAA-89-0975] American Institute of Aeronautics and Astronautics Inc, AIAA.

The delay of turbulent boundary layer separation by oscillatory active control. / Katz, Y.; Nishri, D.; Wygnanski, Israel J.

AIAA 2nd Shear Flow Conference, 1989. American Institute of Aeronautics and Astronautics Inc, AIAA, 1989. AIAA-89-0975.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Katz, Y, Nishri, D & Wygnanski, IJ 1989, The delay of turbulent boundary layer separation by oscillatory active control. in AIAA 2nd Shear Flow Conference, 1989., AIAA-89-0975, American Institute of Aeronautics and Astronautics Inc, AIAA, AIAA 2nd Shear Flow Conference, 1989, Tempe, United States, 3/13/89.
Katz Y, Nishri D, Wygnanski IJ. The delay of turbulent boundary layer separation by oscillatory active control. In AIAA 2nd Shear Flow Conference, 1989. American Institute of Aeronautics and Astronautics Inc, AIAA. 1989. AIAA-89-0975
Katz, Y. ; Nishri, D. ; Wygnanski, Israel J. / The delay of turbulent boundary layer separation by oscillatory active control. AIAA 2nd Shear Flow Conference, 1989. American Institute of Aeronautics and Astronautics Inc, AIAA, 1989.
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