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| DOI： |
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| Analyzing the Impact of Clearance Leakage on Impeller Strength in Centrifugal Pump Using Fluid-solid Coupling |
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GAO Peng, HAN Rujun, QIAO Yu, NIE Zhifeng
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Shandong University of Science and Technology, College of Mechanical and Electronic Engineering, Qingdao 266590, China
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| Abstract: |
| Taking the secondary impeller of DG-350 multistage centrifugal pump as a test model, this paper studied the influence of clearance leakage on secondary impeller deformation and strength based on fluid-structure interaction. The deformation distribution and equivalent stress were obtained from sequential fluid-solid coupling and strong fluid-solid coupling respectively. The results showed that the maximum deformation and the maximum equivalent stress were 0.021 4 mm and 21.51 MPa respectively when the clearance leakage was taken into account, and were 0.053 6 mm and 87 MPa respectively without considering the clearance leakage. The clearance between the wear-rings resulted in a great pressure between the impeller and the fluid guide vanes applied to the impeller front and rear covers. This pressure could offset some fluid pressure on the impeller cavity and hence reduced the deformation and maximum equivalent stress zone on the impeller. Randomly selecting a point A and a point B near the maximum deformation zone and the maximum equivalent stress on the impeller respectively, transition analysis showed that the equivalent stress at points A and B varied periodically with time in the last rotation period. The equivalent stress at node B was always higher than that at node A and was close to the maximum equivalent stress, revealing that the region in the proximity of B has the highest stress. The equivalent stress at node A was less than that at node B, but it fluctuated more profoundly, indicating a likely occurrence of fatigue. |
| Key words: fluid-structure interaction; clearance between the wear-rings; impeller strength |
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