0
Research Papers: Flows in Complex Systems

Fluid Force Moment on the Backshroud of a Francis Turbine Runner in Precession Motion

[+] Author and Article Information
Bingwei Song1

School of Hydraulic Engineering, Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, China; Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japanbingweisong@dl.cn

Hironori Horiguchi, Yumeto Nishiyama, Shinichiro Hata, Yoshinobu Tsujimoto

Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan

Zhenyue Ma

School of Hydraulic Engineering, Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116024, China

1

Corresponding author.

J. Fluids Eng 132(5), 051108 (May 13, 2010) (8 pages) doi:10.1115/1.4001618 History: Received August 02, 2009; Revised April 07, 2010; Published May 13, 2010; Online May 13, 2010

The fundamental characteristics of rotordynamic fluid force moment on the backshroud of a Francis turbine runner in precession motion were studied using model tests and computations based on a bulk flow model. The runner is modeled by a disk positioned close to a casing with a small axial clearance. An inward leakage flow is produced by an external pump in the model test. The effects of the leakage flow rate, the preswirl velocity at the inlet of the clearance, and the axial clearance on the fluid force moment were examined. It was found that the fluid force moment encourages the precession motion at small forward precession angular velocity ratios and the region encouraging the precession motion is affected by the preswirl velocity. Through the comparisons of the fluid force moment with and without the rotation of the disk, it was found that the normal moment without the disk rotation did not have the effect to encourage the precession motion. Thus, the swirl flow due to disk rotation was found to be responsible for the encouragement of the precession motion.

FIGURES IN THIS ARTICLE
<>
Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Schematic of experimental facility: (a) overall view and (b) cross-section of sleeve

Grahic Jump Location
Figure 2

Details of the test section

Grahic Jump Location
Figure 3

Definition of the rotordynamic fluid force moments

Grahic Jump Location
Figure 4

Steady pressure distribution in the clearance: (a) effect of flow rate (C2=4 mm and UJ=0), (b) effect of preswirl flow (C2=4 mm and vl/UT=0.170), and (c) effect of clearance (UJ=0 and vl/UT=0.170)

Grahic Jump Location
Figure 5

Effects of leakage flow rates on fluid force moment in the case of C2=4 mm and UJ/UT=0: (a) normal moment and (b) tangential moment

Grahic Jump Location
Figure 6

Effects of preswirl velocities on fluid force moment in the case of C2=4 mm and vl/UT=0.170: (a) normal moment and (b) tangential moment

Grahic Jump Location
Figure 7

Effects of axial clearance C2 on fluid force moment in the case of vl/UT=0.170, UJ/UT=0: (a) normal moment and (b) tangential moment

Grahic Jump Location
Figure 8

Unsteady components of pressure and velocity in the clearance for Ω/ω=1.2 in the case of C2=4 mm, vl/UT=0.170, and UJ/UT=0: (a) pressure (exp.), (b) pressure (calc.), and (c) velocity (calc.)

Grahic Jump Location
Figure 9

The same as Fig. 8 for Ω/ω=0.3

Grahic Jump Location
Figure 10

The same as Fig. 8 for Ω/ω=−0.3

Grahic Jump Location
Figure 11

The same as Fig. 8 for Ω/ω=−1.2

Grahic Jump Location
Figure 12

Fluid force moment in the cases of precession with and without rotation at C2=4 mm, vl/UT=0.170, and UJ/UT=0: (a) normal moment and (b) tangential moment

Grahic Jump Location
Figure 13

Experimental unsteady components of pressure in the clearance under precession motion without rotation in the case of C2=4 mm, vl/UT=0.170, and UJ/UT=0 at (a) Ω/ω=1.2, (b) Ω/ω=0.3, (c) Ω/ω=−0.3, and (d) Ω/ω=−1.2

Grahic Jump Location
Figure 14

Comparison of fluid force moments obtained by the force sensor, the unsteady pressure, and the computation between the conditions of precession with and without rotation in the case of C2=4 mm, vl/UT=0.170, and UJ/UT=0: (a) normal moment and (b) tangential moment

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