0
TECHNICAL PAPERS

Controlling Turbulence in a Rearward-Facing Step Combustor Using Countercurrent Shear

[+] Author and Article Information
David J. Forliti1

Mechanical Engineering Department University of Minnesota, 111 Church St. SE Minneapolis, MN 55455dforliti@buffalo.edu

Paul J. Strykowski

Mechanical Engineering Department University of Minnesota, 111 Church St. SE Minneapolis, MN 55455

1

Current address: Department of Mechanical and Aerospace Engineering, State University of New York at Buffalo, Buffalo, NY.

J. Fluids Eng 127(3), 438-448 (Jan 25, 2005) (11 pages) doi:10.1115/1.1899170 History: Received February 24, 2004; Revised November 24, 2004; Accepted January 25, 2005

The present work describes the application of countercurrent shear flow control to the nonreacting flow in a novel step combustor. The countercurrent shear control employs a suction based approach, which induces counterflow through a gap at the sudden expansion plane. Peak turbulent fluctuation levels, cross-stream averaged turbulent kinetic energy, and cross-stream momentum diffusion increased with applied suction. The control downstream of the step operates via two mechanisms: enhanced global recirculation and near field control of the separated shear layer. The use of counterflow also enhances three dimensionality, a feature that is expected to be beneficial under burning conditions.

FIGURES IN THIS ARTICLE
<>
Copyright © 2005 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Conventional and countercurrent rearward-facing step geometries

Grahic Jump Location
Figure 2

Countercurrent rearward-facing step geometry parameters

Grahic Jump Location
Figure 3

The effect of sample size on the convergence of first and second order velocity statistics

Grahic Jump Location
Figure 4

Test section initial conditions upstream of expansion plane

Grahic Jump Location
Figure 5

Global and high-resolution instantaneous velocity-vector fields for (a), (c) the base line case and (b), (d) the 10.7% suction mass flow case

Grahic Jump Location
Figure 6

Streamlines for the mean velocity fields for the countercurrent step flow at various suction mass flow levels

Grahic Jump Location
Figure 7

Mean streamwise velocity profiles for a variety of suction mass flows at (a) x∕H=0.1, (b) x∕H=1.0, (c) x∕H=2.0, and (d) x∕H=8.0

Grahic Jump Location
Figure 8

Streamwise velocity ratio distributions for the countercurrent step flow at various suction mass flow levels

Grahic Jump Location
Figure 9

Rms streamwise velocity fluctuation profiles for a variety of suction mass flows at (a) x∕H=1.0, (b) x∕H=2.0, (c) x∕H=3.0, and (d) x∕H=5.0

Grahic Jump Location
Figure 10

Cross-stream averaged turbulent energy distributions for the countercurrent step flow at various suction mass flow levels

Grahic Jump Location
Figure 11

Cross-stream integral length scales for the 0% and 10.7% suction mass flow cases

Grahic Jump Location
Figure 12

Streamwise velocity ratio distributions for gap heights G∕H of 0.15, 0.25, and 0.35 for 9.3% suction mass flow

Grahic Jump Location
Figure 13

Cross-stream averaged turbulent kinetic energy distributions for gap heights G∕H of 0.15, 0.25, and 0.35 for 9.3% suction mass flow

Grahic Jump Location
Figure 14

Spanwise averaged (a) streamwise and (b) spanwise velocity fluctuation levels for 0%, 6.5% and 9.3% suction mass flows

Tables

Errata

Discussions

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 Journal Articles
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