0
TECHNICAL PAPERS

Experimental Analysis on Tip Leakage and Wake Flow in an Axial Flow Fan According to Flow Rates

[+] Author and Article Information
C.-M. Jang1

Senior Researcher, Fire & Engineering Services Research Department,  Korea Institute of Construction Technology, 2311, Dachwa-dong, Goyang-Si, 411-712, Korea jangcm@kict.re.kr

D. Sato, T. Fukano

Department of Mechanical Science and Engineering,  Kyushu University, 6-10-1, Hakozaki, Higashi-Ku, Fukuoka, 812-8581, Japan

1

Corresponding Author.

J. Fluids Eng 127(2), 322-329 (Oct 16, 2004) (8 pages) doi:10.1115/1.1881695 History: Received April 09, 2004; Revised October 16, 2004

The flow characteristics in the blade passage and in the wake region of a low-speed axial flow fan have been investigated by experimental analysis using a rotating hot-wire sensor and a five-hole probe for design and off-design operating conditions. The results show that the tip leakage vortex is moved upstream when the flow rate is decreased, thus disturbing the formation of wake flow near the rotor tip. That is, the tip leakage vortex interfaces with the blade suction surface and results in high velocity fluctuation near the blade suction surface. From axial velocity distributions downstream of the fan rotor, large axial velocity decay near the rotor tip is observed at near-stall condition, which results in a large blockage compared to that at the design condition. Finally, the wake flow downstream of the rotor blade is clearly measured at the design and off-design conditions. However, the trough of the high velocity fluctuation due to Karmann vortex street in the wake flow is observed at a higher flow condition than the design flow rate.

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

Meridional streamlines for the design of an axial flow fan (mm)

Grahic Jump Location
Figure 2

Distribution of design parameters obtained from the Carpet plot

Grahic Jump Location
Figure 3

Blade profile of the designed axial flow fan

Grahic Jump Location
Figure 4

Sound pressure level and total pressure rise

Grahic Jump Location
Figure 5

Schematic view of experimental setup (mm)

Grahic Jump Location
Figure 6

Test blade measuring system

Grahic Jump Location
Figure 7

Calibration curves of five-hole probe

Grahic Jump Location
Figure 8

Distribution of an axial velocity and a tangential velocity downstream of the fan rotor: (a) axial velocity (b) tangential velocity

Grahic Jump Location
Figure 9

Distribution of relative flow angle upstream and downstream of fan rotor at the design operating condition

Grahic Jump Location
Figure 10

Contour of relative velocity on the plane 96% span: (a) Φ=0.28, (b) Φ=0.31, (c) Φ=0.41, and (d) Φ=0.47

Grahic Jump Location
Figure 11

Trajectory of the vortical center of the tip leakage vortex

Grahic Jump Location
Figure 12

Contour of velocity fluctuation on the plane 96% span (a) Φ=0.28, (b) Φ=0.31, (c) Φ=0.41, and (d) Φ=0.47

Grahic Jump Location
Figure 13

Contour of relative velocity and velocity fluctuation on the quasi-orthogonal plane to the tip leakage vortex (Φ=0.41): (a) positions of the quasi-orthogonal planes to the tip leakage vortex, (b) relative velocity, and (c) velocity fluctuation

Grahic Jump Location
Figure 14

Radial positions of the vortical center of a tip leakage vortex

Grahic Jump Location
Figure 15

Perspective view of experimental grid in the wake region

Grahic Jump Location
Figure 16

Contour of relative velocity and velocity fluctuation in the wake region: (a) relative velocity and (b) velocity fluctuation

Grahic Jump Location
Figure 17

Contour of relative velocity and velocity fluctuation on the plane of 68% span in the wake region: (a) relative velocity and (b) velocity fluctuation

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