Control of turbulent separation by periodic suction and injection

Hirofumi Ooizumi, Shinnosuke Obi, Shigeaki Masuda

Research output: Contribution to journalArticle

Abstract

Effects of periodic perturbation on the turbulent separating flows in a plane two-dimensional asymmetric diffuser have been experimentally investigated. The perturbation was accomplished by alternating injection and suction through a two-dimensional slit located upstream of the expected detachment point. The results indicate that the pressure recovery along the diffuser depends on the frequency as well as the amplitude of the injection/suction flow; the maximum improvement was achieved as St approx.0.03, the Strouhal number St being based on the channel width and channel center velocity at the inlet of the diffuser. The phase-averaged velocity distributions at each phase of the oscillation were evaluated by means of synchronized sampling of the velocity signal employing direction-sensible hot-wire anemometry. A wavy pattern of the instantaneous streamlines, obtained from the velocity profiles, extends throughout the entire region of the diffuser, confirming an enhanced momentum transport due to the organized oscillatory fluid motion.

Original languageEnglish
Pages (from-to)123-128
Number of pages6
JournalNippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Volume59
Issue number557
Publication statusPublished - 1993 Jan
Externally publishedYes

Fingerprint

diffusers
suction
injection
Strouhal number
velocity distribution
Phase velocity
pressure recovery
Velocity distribution
perturbation
Turbulent flow
Momentum
velocity measurement
detachment
phase velocity
Wire
turbulent flow
upstream
Sampling
slits
Recovery

ASJC Scopus subject areas

  • Mechanical Engineering

Cite this

Control of turbulent separation by periodic suction and injection. / Ooizumi, Hirofumi; Obi, Shinnosuke; Masuda, Shigeaki.

In: Nippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B, Vol. 59, No. 557, 01.1993, p. 123-128.

Research output: Contribution to journalArticle

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