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

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 65 ◽  
Author(s):  
Qiaorui Si ◽  
Gérard Bois ◽  
Minquan Liao ◽  
Haoyang Zhang ◽  
Qianglei Cui ◽  
...  
Keyword(s):  
Pressure Pulsation ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Internal Flow ◽  
Phase Flow ◽  
Water Mixture ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Void Fractions

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 (α0) 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.

Prediction of Pump Performance Under Air-Water Two-Phase Flow Based on a Bubbly Flow Model

1993 ◽  
Vol 115 (4) ◽  
pp. 781-783 ◽  
Author(s):  
Kiyoshi Minemura ◽  
Tomomi Uchiyama
Keyword(s):  
Two Phase Flow ◽  
Bubbly Flow ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Two Phase ◽  
Performance Change ◽  
Void Fractions ◽  
Two Phases

This paper is concerned with the determination of the performance change in centrifugal pumps operating under two-phase flow conditions using the velocities and void fractions calculated under the assumption of an inviscid bubbly flow with slippage between the two phases. The estimated changes in the theoretical head are confirmed with experiments within the range of bubbly flow regime.

Research Analysis and Experiment Study on Flow Field of Hydrodynamic Coupling

2011 ◽  
Vol 418-420 ◽  
pp. 2006-2011
Author(s):  
Rui Zhang ◽  
Cheng Jian Sun ◽  
Yue Wang
Keyword(s):  
Flow Field ◽  
Cfd Simulation ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Internal Flow ◽  
Phase Flow ◽  
Complex Flow ◽  
Two Phase ◽  
Operation Conditions ◽  
Hydrodynamic Coupling

CFD simulation and PIV test technology provide effective solution for revealing the complex flow of hydrodynamic coupling’s internal flow field. Some articles reported that the combination of CFD simulation and PIV test can be used for analyzing the internal flow field of coupling, and such analysis focuses on one-phase flow. However, most internal flow field of coupling are gas-fluid two-phase flow under the real operation conditions. In order to reflect the gas-fluid two-phase flow of coupling objectively, CFD three-dimensional numerical simulation is conducted under two typical operation conditions. In addition, modern two-dimensional PIV technology is used to test the two-phase flow. This method of combining experiments and simulation presents the characteristics of the flow field when charging ratios are different.

Effects of moisturized inflow on compressor performance and aerodynamic noise

2021 ◽  
Vol 263 (1) ◽  
pp. 5467-5474
Author(s):  
Changhong Sun ◽  
Yipeng Cao ◽  
Chen Liu
Keyword(s):  
Two Phase Flow ◽  
Flow Characteristics ◽  
Water Concentration ◽  
Internal Flow ◽  
Aerodynamic Noise ◽  
Outlet Temperature ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Method ◽  
Compressor Performance

The effects of moisturized inflow on turbocharger compressor performance and aerodynamic noise were numerical analyzed in this paper. The gas-liquid two-phase flow method based on Euler-Lagrange model was firstly introduced. The influence of water concentration and water droplet diameter on compressor performance and internal flow characteristics at design speed were studied using the two-phase flow method. The compressor aerodynamic noise was also predicted at design condition under two different inflow conditions, including ideal inflow and moisturized inflow with 0.1% water concentration. The results indicate that moisturized inflow with an appropriate water concentration can reduce the outlet temperature of the compressor and improve the compressor performance, in which the water concentration is a dominant parameter. There is a phase transition process of water in the compressor with moisturized inflow, but moisturized inflow has little effects on the compressor internal flow characteristics. Moreover, the moisturized inflow also has influence on compressor aerodynamic noise.

scholarly journals Investigation on the Handling Ability of Centrifugal Pumps under Air–Water Two-Phase Inflow: Model and Experimental Validation

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3048 ◽  
Author(s):  
Qiaorui Si ◽  
Gérard Bois ◽  
Qifeng Jiang ◽  
Wenting He ◽  
Asad Ali ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Two Phase Flow ◽  
Bubbly Flow ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Flow Conditions ◽  
Two Phase ◽  
Local Flow

The paper presents experimental and numerical investigations performed on a single stage, single-suction, horizontal-orientated centrifugal pump in air–water two-phase non-condensable flow conditions. Experimental measurements are performed in a centrifugal pump using pressure sensor devices in order to measure the wall static pressures at the inlet and outlet pump sections for different flow rates and rotational speeds combined with several air void fraction (a) values. Two different approaches are used in order to predict the pump performance degradations and perform comparisons with experiments for two-phase flow conditions: a one-dimensional two-phase bubbly flow model, and a full “Three-Dimensional Unsteady Reynolds Average Navier–Stokes” (3D-URANS) simulation using a modified k-epsilon turbulence model combined with the Euler–Euler inhomogeneous two-phase flow description. The overall and local flow features are presented and analyzed. Limitations concerning both approaches are pointed out according to some flow physical assumptions and measurement accuracies. Some additional suggestions are proposed in order to improve two-phase flow pump suction capabilities.

Numerical Analysis of Two-Phase Flow in Gas-Stirred Reactors

1990 ◽  
Vol 204 (5) ◽  
pp. 311-319
Author(s):  
Y M Ferng ◽  
C C Chieng ◽  
C Pan
Keyword(s):  
Experimental Data ◽  
Liquid Metal ◽  
Two Phase Flow ◽  
Gas Injection ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Water Model ◽  
Phase Flow ◽  
Two Phase ◽  
Stirred Reactors

Using the multi-dimensional, turbulent, two-phase flow model, the fluid flow phenomena for gas injecting through a submerged lance in gas-stirred reactors are investigated numerically by a finite difference algorithm. The present numerical model is validated by comparison with the experimental data of the water model and extended to predict the flow fields and mixing phenomena inside the liquid metal model. This study indicates that the flow characteristics and mixing behaviour of the water model are similar to the metal model and the experimental data of the water model can be an important reference for the design of liquid metal reactors. The investigations consist of central (two-dimensional) and off-centred gas injection (three-dimensional) with full—and fractional—depth of lance submergence and with different gas injection rates.

scholarly journals Simulation Analysis of Capacitance Method in Two-Phase Flow Concentration Measurement by Coupled Fields

2016 ◽  
Author(s):  
Xiaoxin Wang ◽  
Hongli Hu ◽  
Lin Li ◽  
Bo Wang
Keyword(s):  
Numerical Simulation ◽  
Two Phase Flow ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Simulation Method ◽  
Concentration Measurement ◽  
Phase Flow ◽  
Two Phase ◽  
Time Dynamic

This paper proposed three-dimensional numerical simulation method by coupling of electrostatic and fluid fields to evaluating the performance of electrical sensor in the concentration measurement of gas/solid two-phase flow. Compared with the static numerical simulation, this real-time dynamic 3-D simulation method can research on a designed capacitance sensor combining the dynamic characteristics of the two-phase flows for concentration measurement. Several fluid-electrostatic models of transmission pipes with different sensor structures are built. Under different test positions and different particle concentrations, the flow characteristics and the corresponding electric signals can be obtained, and the correlation coefficient between the concentration values and the capacitance values are used for performance evaluation of the sensors. The effects of flow regimes on concentration measurement are also been investigated in this paper. To validate the results of simulation, an experimental platform with horizontal straight pipe for phase volume concentration measurement of solid/air two-phase flow is built, and the experimental results agree well with simulation conclusions. The simulation and test results show that the coupling models can give constructive reference opinions for the sensor design and collection of installation position in different transmission pipelines, which are very important for the practical process of pneumatic conveying system.

scholarly journals Startup Characteristics of a Centrifugal Pump Delivering Gas-Liquid Two-Phase Flow

2014 ◽  
Vol 6 ◽  
pp. 782619 ◽  
Author(s):  
Yu-Liang Zhang ◽  
Jun-Jian Xiao ◽  
Jian-Ping Yu ◽  
Ying-Yu Ji
Keyword(s):  
Centrifugal Pump ◽  
Two Phase Flow ◽  
Pure Water ◽  
Internal Flow ◽  
Phase Flow ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Transient Flows ◽  
The Difference ◽  
Startup Period

The transient performance of centrifugal pumps during the startup period has drawn more and more attention in recent years due to urgent engineering needs. In order to make certain the transient startup characteristics of a high specific-speed prototype centrifugal pump delivering the gas-liquid two-phase flow, the transient flows inside the pump are numerically simulated during the startup period using the dynamic slip region method in this paper. The results show that the difference in heads mainly focuses on the later stage of the startup period when the pump is used to transmit the pure water and the gas-liquid two-phase flow, respectively. The existence of the gas phase makes the head less than that of delivering pure water. The nondimensional head coefficient is very high at the very beginning of the startup period and then quickly drops to a stable value. The continuous variation of the attack angle at the leading edges of blades is the main reason for evolution of the internal flow field during the startup period.

Experimental Characterization of Two-Phase Flow Centrifugal Pumps

2010 ◽  
Author(s):  
Antonio Campo ◽  
Eugene A. Chisely
Keyword(s):  
High Speed ◽  
Two Phase Flow ◽  
Small Diameter ◽  
High Speed Photography ◽  
Phase Flow ◽  
Water Mixture ◽  
Centrifugal Pumps ◽  
Two Phase ◽  
Wide Range ◽  
Radial Pump

In this experimental work, the pressure distribution was measured in a rotating, partially shrouded, open, radial impeller, inlet diffuser and volute under a wide range of air-water two-phase flow conditions. To obtain these pressure measurements, small-diameter pressure-tap holes were drilled through the casing of the radial pump. High speed photography was the vehicle to determine the flow regime of the air-water mixture through the vane and in the volute. An analytical model was developed to predict the radial pump single- and two-phase flow pressure distributions. The distribution for the latter was compared with the test data for different suction void fractions. The physical mechanism responsible for pump performance degradation was also investigated.

INVESTIGATION OF STRATIFIED WAVY TWO-PHASE FLOW CHARACTERISTICS

Equipment ◽  
2006 ◽  
Author(s):  
Marijus Seporaitis ◽  
S. Gasiunas ◽  
Raimondas Pabarcius
Keyword(s):  
Two Phase Flow ◽  
Flow Characteristics ◽  
Phase Flow ◽  
Two Phase
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