0

Full Content is available to subscribers

Subscribe/Learn More  >

Active Flow Control With an Oscillating Backward Facing Step

[+] Author Affiliations
Sertac Cadirci, Hasan Gunes

Istanbul Technical University, Istanbul, Turkey

Paper No. ESDA2012-82645, pp. 193-199; 7 pages
doi:10.1115/ESDA2012-82645
From:
  • ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis
  • Volume 2: Applied Fluid Mechanics; Electromechanical Systems and Mechatronics; Advanced Energy Systems; Thermal Engineering; Human Factors and Cognitive Engineering
  • Nantes, France, July 2–4, 2012
  • Conference Sponsors: International
  • ISBN: 978-0-7918-4485-4
  • Copyright © 2012 by ASME

abstract

An oscillatory, zero-net-mass flux actuator system, Jet and Vortex Actuator (JaVA), is implemented on the step wall of a backward facing step. JaVA is shown previously both experimentally and numerically that it can energize the boundary layer by creating jets or vortices thus it may delay flow separation when used properly. The main part of JaVA is a rectangular cavity with a moving actuator plate. The actuator plate is mounted asymmetrically inside the cavity of the JaVA box, such that there are one narrow and one wide gap between the plate and the box. The main governing parameters are the actuator plate’s width (b), the amplitude (a) and the operating frequency (f). The main target of the control with active jets on the step wall is to influence directly the main recirculation zone, thus as the actuator plate or the step’s vertical wall moves periodically in horizontal direction, a jet emerges into the recirculation zone. Non-dimensional numbers such as the scaled amplitude (Sa = 2πa/b) and the jet Reynolds number (ReJ = 4abf/ν) as well as the maximum cross flow velocity characterize the JaVA-induced flow types and effects on the recirculation zone. One period consists of one blowing and one suction phase into the recirculation zone. The actuator plate has a sinusoidal motion determined by the amplitude and the operating frequency. Time-averaged flow fields and boundary layer profiles for actuated and not actuated cases at various operating frequencies indicate the effect of active flow control. The control effectiveness is given by the ratio of the jet Reynolds number to the Reynolds number of the incoming flow (r = ReJ/Re). A transient finite-volume-based laminar, incompressible Navier-Stokes solver (Fluent) has been used to study the flow fields generated by JaVA. The computational domain consists of a moving zone along the channel and the motion of the actuator plate is generated by a moving grid imposing appropriate boundary conditions with User-Defined-Functions (UDF). Numerical simulations reveal the JaVA-boundary layer interaction in the narrow channel for various governing parameters such as frequencies (jet Reynolds numbers) and channel flow velocities (Reynolds numbers, Re = 200, 400 and 800). The proposed control method based on suction and blowing with an oscillating backward facing step (OsBFS) seems to be effective in shortening the recirculation zone length and delaying the flow separation downstream of the backward facing step.

Copyright © 2012 by ASME
Topics: Flow control

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In