Numerical Study on the Gas-Water Two-Phase Flow in the Self-Priming Process of Self-Priming Centrifugal Pump

Wang, Chuan; Hu, Bo; Zhu, Yong; Wang, Xiuli; Luo, Can; Cheng, Li

doi:10.3390/pr7060330

Cited by 47 publications

(44 citation statements)

References 21 publications

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“…e waterjet propulsion pump is the core part of a waterjet propulsion system. Tan et al [25,26], He et al [27], and Wang et al [28] have done relevant work on the hydraulic performance of mixed-flow pumps and centrifugal pumps. e research results can provide guidance for the optimization of waterjet propulsion pumps.…”

Section: Introductionmentioning

confidence: 99%

Optimal Design of Inlet Passage for Waterjet Propulsion System Based on Flow and Geometric Parameters

Jiao

Cheng

Zhang

et al. 2019

Advances in Materials Science and Engineering

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As an important overcurrent component in a waterjet propulsion system, the inlet passage is used to connect the propulsion pump and the bottom of the propulsion ship. e anticavitation, vibration, and noise performance of the waterjet propulsion pump are significantly affected by the hydraulic performance of the inlet passage. e hydraulic performance of the inlet passage directly affects the overall performance of the waterjet propulsion system, thus the design and optimization method of the inlet passage is an important part of the hydraulic optimization of the waterjet propulsion system. In this study, the hydraulic characteristics of the inlet passage in the waterjet propulsion system with different flow parameters and geometric parameters were studied by a combination of numerical simulation and experimental verification. e model test was used to verify the hydraulic characteristics of the waterjet propulsion system, and the results show that the numerical results are in good agreement with the test results. e numerical results are reliable. e hydraulic performance of the inlet passage is significantly affected by the inlet velocity ratio.ere is a certain correlation between the hydraulic performance of the inlet passage and ship speed, and the hydraulic performance of the inlet passage is limited by ship speed. e geometric parameters of the best optimization case are as follows: the inflow dip angle α is 35°, the length L is 6.38D 0 , and the upper lip angle is 4°. e optimal operating conditions are the conditions of IVR 0.69-0.87.

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Section: Introductionmentioning

confidence: 99%

Optimal Design of Inlet Passage for Waterjet Propulsion System Based on Flow and Geometric Parameters

Jiao

Cheng

Zhang

et al. 2019

Advances in Materials Science and Engineering

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“…It would significantly increase the calculation time if we set a small time step. Courant number defined by Equation (14) is always used as criterion to judge if the time step satisfies the periodic numerical simulation [30]:…”

Section: Boundary Conditionsmentioning

confidence: 99%

A Comparative Study on Centrifugal Pump Designs and Two-Phase Flow Characteristic under Inlet Gas Entrainment Conditions

Bois

Liao

et al. 2019

Energies

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Capability for handling entrained gas is an important design consideration for centrifugal pumps used in petroleum, chemistry, nuclear applications. An experimental evaluation on their two phase performance is presented for two centrifugal pumps working under air-water mixture fluid conditions. The geometries of the two pumps are designed for the same flow rate and shut off head coefficient with the same impeller rotational speed. Overal pump performance and unsteady pressure pulsation information are obtained at different rotational speeds combined with various inlet air void fractions (α 0 ) up to pump stop condition. As seen from the test results, pump 2 is able to deliver up to 10% two-phase mixtures before pump shut-off, whereas pump 1 is limited to 8%. In order to understand the physics of this flow phenomenon, a full three-dimensional unsteady Reynolds Average Navier-Stokes (3D-URANS) calculation using the Euler-Euler inhomogeneous method are carried out to study the two phase flow characteristics of the model pump after corresponding experimental verification. The internal flow characteristics inside the impeller and volute are physically described using the obtained air distribution, velocity streamline, vortex pattern and pressure pulsation results under different flow rates and inlet void fractions. Pump performances would deteriorate during pumping two-phase mixture fluid compared with single flow conditions due to the phase separating effect. Some physical explanation about performance improvements on handing maximum acceptable inlet two phase void fractions capability of centrifugal pumps are given.Energies 2020, 13, 65 2 of 25 of the flow pattern. The pump performance degrades as the α 0 increase and generates undesired pulsation problems, endangering the operation stability and reliability of the system [4,5]. Therefore, it is especially important to thoroughly study and reveal the internal flow characteristic of centrifugal pumps under gas entrainment conditions. Several pioneering relevant studies on the basic theory, numerical simulation and experiment of how gas-entrainment affects pump performance degradation have been done. Murakami and Minemura [6,7] firstly conducted experimental works and developed a two-phase, one dimensional, flow model. In their research hydraulic-head degradation and abrupt flow-pattern changes were observed as more air entered the system. Furukawa et al. [8,9] designed a centrifugal pump using an outlet impeller blade angle greater than 90 • with a set of tandem blades. They obtained rather good two-phase flow performances, but their design failed at low flow rates. It is also known that open impellers have better capabilities than shrouded ones with respect to two phase flows due to the stronger mixing created by tip blade leakage and induced vortex flows structures (Cappellino et al. [10], Mansour et al. [11]). Flow patterns play an important role affecting hydraulic performance and energy conversion, even in the single phase flow of centrifugal pumps [12]. Releva...

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“…Pumps are classified as general machinery with varied applications [1][2][3][4][5]. Sewage pump, as important equipment in the sewage treatment project, is widely used in chemical, municipal, and other industries.…”

Section: Introductionmentioning

confidence: 99%

Influence of Critical Wall Roughness on the Performance of Double-Channel Sewage Pump

Zhang

Wang

et al. 2020

Energies

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The numerical method on a double-channel sewage pump was studied, while the corresponding experimental result was also provided. On this basis, the influence of wall roughness on the pump performance was deeply studied. The results showed that there was a critical value of wall roughness. When the wall roughness was less than the critical value, it had a great influence on the pump performance, including the head, efficiency, and shaft power. As the wall roughness increased, the head and efficiency were continuously reduced, while the shaft power was continuously increased. Otherwise, the opposite was true. The effect of wall roughness on the head and hydraulic loss power was much smaller than that on the efficiency and disk friction loss power, respectively. With the increase of wall roughness, mechanical efficiency and hydraulic efficiency reduced constantly, leading to the decrement of the total efficiency. With the increase of flow rate, the effect of wall roughness on the head and efficiency gradually increased, while the influence on the leakage continuously reduced. The influence of the flow-through component roughness on the pump performance was interactive.Energies 2020, 13, 464 2 of 20 Literature OverviewIn the past years, many scholars studied the effect of wall roughness on the flow in pipes, fans, compressors, microchannels. In order to study the effect of wall roughness in turbulent pipe flow, Hemeida [17] developed an equation for estimating the thickness of the laminar sublayer in turbulent pipe flow of pseudoplastic fluids and found that the turbulent pipe flow could be divided into two regions: smooth wall and rough wall turbulence. The roughness Reynolds number was used to determine the smooth wall turbulence and rough wall turbulence regions. Kandlikar [18] studied the roughness effects at microscale-reassessing Nikuradse's experiments on liquid flow in rough tubes, and found that Nikuradse's work was revisited in light of the recent experimental work on roughness effects in microscale flow geometries. Li et al. [19] studied the influence of the internal surface roughness of the nozzle on cavitation erosion characteristics of submerged cavitation jets from the aspects of erosion intensity and erosion efficiency; it could be concluded that excessive smooth surface was not conducive to the formation of cavitation bubbles, leading to an attenuated intensity of cavitation erosion, while excessive rough surface caused much energy dissipation and led to divergent jets, resulting in a significant reduction of erosion intensity. According to the experimental results, there existed an optimum inner surface roughness value to achieve the strongest aggressive cavitation erosion capability for submerged cavitating jets. Tang et al. [20] analyzed the existing experimental data in the literature on the friction factor in microchannels. The friction factors in stainless steel tubes were much higher than the theoretical predictions for tubes of conventional size. This discrepancy resulted from the large rel...

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Numerical Study on the Gas-Water Two-Phase Flow in the Self-Priming Process of Self-Priming Centrifugal Pump

Cited by 47 publications

References 21 publications

Optimal Design of Inlet Passage for Waterjet Propulsion System Based on Flow and Geometric Parameters

Optimal Design of Inlet Passage for Waterjet Propulsion System Based on Flow and Geometric Parameters

A Comparative Study on Centrifugal Pump Designs and Two-Phase Flow Characteristic under Inlet Gas Entrainment Conditions

Influence of Critical Wall Roughness on the Performance of Double-Channel Sewage Pump

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