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LI
Yang
OUYANG Hua
DU Zhaohui
School of Mechanical Engineering, Shanghai
Jiaotong University,
Shanghai 200030, China
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COMPUTATIONAL AND EXPERIMENTAL STUDY ON TIP LEAKAGE
VORTEX OF CIRCUMFERENTIAL
SKEWED BLADES*
Abstract:
In the steady operation condition, the experiments and the
numerical simulations are used to investigate the tip leakage
flow fields in three low pressure axial flow fans with three
kinds of circumferential skewed rotors, including the radial
rotor, the forward-skewed rotor and the back-ward-skewed rotor.
The three-dimensional viscous flow fields of the fans are
computed. In the experiments, the two-dimensional plane particle image velocimetry (PIV) system is used to measure the flow fields in the tip region of three different pitchwise positions of each fan. The results show that the computational results agree well with the experimental data in the flow field of the tip region of each fan. The tip leakage vortex core segments based on method of the eigenmode analysis can display clearly some characteristics of the tip leakage vortex, such as the origination position of tip leak-age vortex, the development of vortex strength, and so on. Compared with the radial rotor, the other two skewed rotors can increase the stability of the tip leakage vortex and the increment in the for-ward-skewed rotor is more than that in the backward-skewed one. Among the tip leakage vortices of the three rotors, the velocity of the vortex in the forward-skewed rotor is the highest in the circumferential direction and the lowest in the axial direction.
Key words:
Low pressure axial flow fan Tip leakage vortex Particle image velocimetry (PIV)
Eigenmode analysis
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