0
Research Papers: Fundamental Issues and Canonical Flows

Influence of Curvature and Pressure Gradient on Turbulent Wake Development in Curved Channels

[+] Author and Article Information
M. T. Schobeiri

Turbomachinery Performance and Flow Research Laboratory, Texas A&M University, College Station, TX 77843-3123tschobeiri@mengr.tamu.edu

J. Fluids Eng 130(9), 091201 (Aug 11, 2008) (14 pages) doi:10.1115/1.2953225 History: Received October 31, 2006; Revised March 31, 2008; Published August 11, 2008

The development of steady wake flow downstream of a cylindrical rod within a curved channel under the influence of positive, negative, and zero streamwise pressure gradients is theoretically and experimentally investigated. The measured asymmetric wake quantities, such as the mean velocity, turbulent fluctuations in longitudinal and lateral directions, and the turbulent shear stress, are transformed from the probe coordinate system into the curvilinear wake coordinate system. For the transformed nondimensionalized velocity defect and the turbulent quantities, affine profiles are observed throughout the flow regime. Based on the experimental observations and using the transformed equations of motion and continuity, a theoretical framework that generally describes a two-dimensional curvilinear steady wake flow is developed. The theory treats the straight wake flow as a special case for which the curvature radius approaches infinity. A comparison of the developed theory with our own experimental results and with the re-evaluated experimental data from the literature establishes the general validity of the theory.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Curved channel test section: 1, exit duct; 2, convex wall assembly; 3, concave wall; 4, probe; 5, wake generator; 6, motor; 7, top wall; 8, safety pin; 9, rotary vernier; 10, traversing system; 11, stepper motor; 12, locking wheel.

Grahic Jump Location
Figure 5

(a) Radial position and (b) local curvature of the wake center

Grahic Jump Location
Figure 6

Mean longitudinal velocity for (a) zero, (b) positive, and (c) negative pressure gradient cases

Grahic Jump Location
Figure 7

Nondimensional mean velocity defect for (a) zero, (b) positive, and (c) negative pressure gradient cases

Grahic Jump Location
Figure 8

Mean lateral velocity for (a) zero, (b) positive, and (c) negative pressure gradient cases

Grahic Jump Location
Figure 2

Schematic velocity distribution, wake defect

Grahic Jump Location
Figure 3

Nondimensional product of maximum velocity defect and wake width for a curved channel

Grahic Jump Location
Figure 4

Nondimensional (a) momentum thickness ratio and (b) shape factor

Grahic Jump Location
Figure 9

Reynolds shear stress for (a) zero, (b) positive, and (c) negative pressure gradient cases

Grahic Jump Location
Figure 10

Nondimensional mean velocity defect for (a) d=2mm and (b) d=0.5mm; comparison with data from Eifler (2)

Grahic Jump Location
Figure 11

Reynolds shear stress for (a) d=2mm and (b) d=0.5mm; comparison with data from Eifler (2)

Grahic Jump Location
Figure 12

(a) Mean velocity defect and (b) mean longitudinal velocity; comparison with data from Nakayama (7)

Grahic Jump Location
Figure 13

(a) Mean lateral velocity and (b) Reynolds shear stress; comparison with data from Nakayama (7)

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.

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