Fluid-structure interaction study of a mixed-flow pump impeller during startup
Abstract
Purpose
The purpose of this paper is to experimentally and numerically study the transient hydraulic impact and overall performance during startup accelerating process of mixed-flow pump.
Design/methodology/approach
In this study, the impeller rotor vibration characteristics during the starting period under the action of fluid–structure interaction was investigated, which is based on the bidirectional synchronization cooperative solving method for the flow field and impeller structural response of the mixed-flow pump. Experimental transient external characteristic and the transient dimensionless head results were compared with the numerical calculation results, to validate the accuracy of numerical calculation method. Besides, the deformation and dynamic stress distribution of the blade under the stable rotating speed and accelerating condition were studied based on the bidirectional fluid–structure interaction.
Findings
The results show that the combined action of complex hydrodynamic environment and impeller centrifugal force in the startup accelerating process makes the deformation and dynamic stress of blade have the rising trend of reciprocating oscillation. At the end of acceleration, the stress and strain appear as transient peak values and the transient effect is nonignorable. The starting acceleration has a great impact on the deformation and dynamic stress of blade, and the maximum deformation near the rim of impeller outlet edge increases 5 per cent above the stable condition. The maximum stress value increases by about 68.7 per cent more than the steady-state condition at the impeller outlet edge near the hub. The quick change of rotating speed makes the vibration problem around the blade tip area more serious, and then it takes the excessive stress concentration and destruction at the blade root.
Originality/value
This study provides basis and reference for the safety operation of pumps during starting period
Keywords
Acknowledgements
The work was sponsored by the National Natural Science Foundation of China (No. 51679111, No. 51409127 and No. 51579118), PAPD, Six Talents Peak Project of Jiangsu Province (No. HYZB-002), Key R&D projects in Jiangsu Province (BE2015119, BE2015001-4, BE2016319, BE2017126), the Natural Science Foundation of Jiangsu Province (No. BK20161472), Science and Technology Support Program of Changzhou (No. CE20162004); and Scientific Research Start Foundation Project of Jiangsu University (No. 13JDG105).
Citation
Li, W., Ji, L., Shi, W., Zhou, L., Jiang, X. and Zhang, Y. (2018), "Fluid-structure interaction study of a mixed-flow pump impeller during startup", Engineering Computations, Vol. 35 No. 1, pp. 18-34. https://doi.org/10.1108/EC-01-2016-0043
Publisher
:Emerald Publishing Limited
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