Open Access

ARTICLE

Numerical Study of the Effect of Splitter Blades on the Flow-Induced Noise of Hydraulic Turbine

by Fengxia Shi^1,2, Guangbiao Zhao^1,*, Yucai Tang¹, Haonan Zhan¹, Pengcheng Wang¹

1 School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, 730050, China
2 Key Laboratory of Fluid Machinery and Systems of Gansu, Lanzhou, 730050, China

* Corresponding Author: Guangbiao Zhao. Email:

Sound & Vibration 2024, 58, 101-117. https://doi.org/10.32604/sv.2024.047082

Received 24 October 2023; Accepted 22 January 2024; Issue published 11 March 2024

Abstract

In order to study the effect of splitter blades on the internal and external sound field of the hydraulic turbine, the paper chose a centrifugal pump with a specific speed n_s = 33 reversed as a hydraulic turbine as the research object, and added the short blades on the original impeller to form a new splitter impeller. Based on the Re-Normalization Group (RNG) k-ε turbulence model to conduct numerical simulation for the hydraulic turbine, this thesis calculated the internal and external acoustic field by means of the acoustic boundary element (BEM) and finite element (FEM) and analyzed the noise radiation characteristics of the two models under different working conditions. The results show that the blade frequency is the main factor affecting the inlet and outlet sound pressure, and the optimized model decreases the inlet and outlet sound pressure levels by 6.84 and 7.24 dB in optimal working conditions. Rotor-stator interaction is the main reason for the flow-induced noise of hydraulic turbine volute appearing, the optimized model can effectively reduce the impeller and volute rotor-stator interaction and the flow-induced noise of volute. Outfield maximum sound pressure appears at the inlet and the volute tongue, which decreased by 1.84, 6.07, and 5.24 dB at each operating condition. To sum up, splitter blades can improve hydraulic characteristics and flow field noise in the hydraulic turbine.

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Keywords

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