0
TECHNICAL PAPERS

Numerical Simulation of Vortex Shedding and Lock-in Characteristics for a Thin Cambered Blade

[+] Author and Article Information
Baoshan Zhu1

State Key Laboratory of Hydroscience and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, P.R.C.bszhu@mail.tsinghua.edu.cn

Jun Lei, Shuliang Cao

State Key Laboratory of Hydroscience and Engineering, Department of Thermal Engineering, Tsinghua University, Beijing 100084, P.R.C.

1

Corresponding author.

J. Fluids Eng 129(10), 1297-1305 (Apr 28, 2007) (9 pages) doi:10.1115/1.2776964 History: Received July 04, 2006; Revised April 28, 2007

In this paper, vortex-shedding patterns and lock-in characteristics that vortex-shedding frequency synchronizes with the natural frequency of a thin cambered blade were numerically investigated. The numerical simulation was based on solving the vorticity-stream function equations with the fourth-order Runge–Kutta scheme in time and the Chakravaythy–Oscher total variation diminishing (TVD) scheme was used to discretize the convective term. The vortex-shedding patterns for different blade attack angles were simulated. In order to confirm whether the vortex shedding would induce blade self-oscillation, numerical simulation was also carried out for blade in a forced oscillation. By changing the pitching frequency and amplitude, the occurrence of lock-in at certain attack angles was determined. Inside the lock-in zone, phase differences between the blade’s pitching displacement and the torque acting on the blade were used to infer the probability of the blade self-oscillation.

Copyright © 2007 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The tested thin cambered blade with maximum camber y∕c=0.038 at x∕c=0.40 and blade thickness t∕c=0.036 at x∕c=0.27

Grahic Jump Location
Figure 2

O grid around the blade

Grahic Jump Location
Figure 3

Comparison of streamline for Re=3000 at T=5.0: (a) present method, grid density 120×150, ΔT=0.005; (b) present method, grid density 180×220, ΔT=0.0025; and (c) flow visualization by Bouard and Coutanceau (18)

Grahic Jump Location
Figure 4

Comparison of drag coefficient: Re=3000

Grahic Jump Location
Figure 5

Time variation in lift and drag coefficients: Re=3000

Grahic Jump Location
Figure 6

Vortex patterns at f∕fs=1.0 and Am=2.0 in a cycle T: (a) T∕4, (b) T∕2, (c) 3T∕4, and (d) T

Grahic Jump Location
Figure 7

Lift and drag coefficients at f∕fs=1.0 and Am=2.0

Grahic Jump Location
Figure 8

Time variations for lift force and torque: (a) α=−8.3deg and (b) α=13.7deg

Grahic Jump Location
Figure 9

Instantaneous flow patterns for α=−8.3deg: (a) calculated streamline at T=14.40; (b) flow visualization (3)

Grahic Jump Location
Figure 10

Calculated streamline contours in a cycle: α=−8.3deg

Grahic Jump Location
Figure 11

Calculated streamline contours in a cycle: α=13.7deg

Grahic Jump Location
Figure 12

Variation of averaged torque and vortex-shedding frequency with attack angle α: (a) α=−8.3deg and (b) α=13.7deg

Grahic Jump Location
Figure 13

Calculated streamline contours in an oscillation cycle for α¯=−8.3deg, Δα=5.0deg: (a) St∕Sts=0.92 and (b) St∕Sts=0.68

Grahic Jump Location
Figure 14

Time histories of the oscillation displacement Δαsin(2πft) and torque Cm on the blade for α¯=−8.3deg, Δα=5.0deg: (a) St∕Sts=0.92 and (b) St∕Sts=0.68

Grahic Jump Location
Figure 15

Lock-in boundaries for two different attack angles: (a) α¯=−8.3deg and (b) α¯=−4.3deg

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