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Zhi-Jun Shuai 1 and Wan-You Li 1 and Xiang-Yuan Zhang 1 and Chen-Xing Jiang 2 and Feng-Chen Li 2
Academic Editor:Jinjia Wei
1, College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001, China
2, School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Received 15 February 2014; Revised 17 March 2014; Accepted 17 March 2014; 9 April 2014
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1. Introduction
For a water pump, the pressure fluctuation and unsteady dynamic forces induced by the complex and rotating inner turbulent flow are one of the main reasons causing vibration of pump components and hydraulic noises. With the more and more applications of pumps, the unstable operation problem caused by hydraulic excitation has been becoming increasingly prominent. Due to its crucial impact on pump design and operations, the investigation of pressure fluctuations in pumps is of continuous interest.
In the past, many experimental and numerical investigations have been carried out to capture the unsteady interactions between turbulent flow and solid structures in pumps and investigate the frequency characteristics of pressure fluctuations. The fast Fourier transform (FFT) method was often used to obtain the spectra of pressure fluctuations as a function of position and flow rate in the posttest data analysis [1]. Parrondo-Gayo et al. [2] investigated the unsteady pressure distribution existing in the volute of a conventional centrifugal pump by means of four piezoresistive pressure transducers mounted at 36 locations around the front side of the volute casing. Their experiments demonstrated a strong increase in the magnitude of dynamic forces and dipole-like sound generation in off-design conditions. It is principally a consequence of the interaction of nonuniform outflux from impeller to tongue [3, 4]. Barrio et al. [5] presented a study on the fluid-dynamic fluctuations in a centrifugal pump with different radial gaps between the impeller and the volute. For a given impeller diameter, the dynamic load increases for off-design conditions, especially for the low range of flow rates, whereas the progressive reduction of the impeller-tongue gap brings about corresponding increments in dynamic load. Wang...