Geometry Effects on Flow Instabilities of Different Three-Bladed Inducers

Abstract

The paper presents the results of an activity carried out on a three-bladed inducer and compares the experimental data from other similar inducers. All the inducers considered in the present study have been designed by means of the simplified analytical model recently developed by some of the authors. The main effects of different geometrical solutions on hydraulic performance and flow instabilities of the pumps under noncavitating and cavitating conditions are presented in the paper

Experimental Characterization of Unsteady Forces Triggered by Cavitation on a Centrifugal Pump

“…The pressure fluctuations of the flow through the pump triggered or not by cavitation have been investigated during the cavitating experiments. Cervone et al [16], and Pace et al [29] report the procedures already exploited by the authors and summarized here. As for the cavitating performance evaluation, the signals, acquired by means of the piezoelectric transducers located on the casing of the pump and the diffuser, are divided into sub-blocks.…”

“…Continuous cavitating experiments are performed by linearly lowering the inlet pressure in order to reach different cavitating regimes; the pressure decrease rate is approximately 0.003 bar/s. Signals are acquired at 5000 samples per second and each continuous experiment is divided into sub-blocks of 5 s in order to allow a quasi-steady hypothesis as experimentally demonstrated in previous works [17,29] and highlighted in the following results. Per each sub-block the operating conditions and relevant phenomena do not change significantly.…”

Effect of Tip Clearance on the Internal Flow and Hydraulic Performance of a Three-Bladed Inducer

“…The inlet duct was modified with an extended portion about 20 times of the inducer inlet radius, , and the outlet duct was also extended in the same way. The main geometrical and operational characteristics of the DAPROT3 inducer were demonstrated in detail by Pace et al [8,9], respectively.…”

“…Computations have been carried out by means of the commercial ANSYS CFX 14.5 software package installed at Jiangsu University, Zhenjiang City, China, in the blade high-performance computing clusters system, whose main operational parameters are listed in Table 1. Reference validation experiments have been carried out in the CPRTF (Cavitating Pump Rotordynamic Test Facility) [7] at ALTA, Pisa, Italy, on the three-bladed inducer with two values of the blade tip clearances, designed as described in Pace et al [8] and manufactured in 7075-T6 aluminum alloy [8].…”

Effect of gas quantity on two-phase flow characteristics of a mixed-flow pump

“…[16][17][18][19] Moreover, some researchers have done deep research work to reveal flow mechanism under cavitation state, [20][21][22][23] and some cavitation-induced unsteady flow characteristics have also been investigated through numerical and experimental ways. [24][25][26][27] In the literatures, there is little open study and analysis on gas-liquid two-phase flow in the mixed-flow pump. In this article, the effects of gas volume fraction on the two-phase flow performance of an industrial mixed-flow pump are studied in detail.…”