Numerical Prediction of a Multistage Centrifugal Pump Performance With Stationary and Moving Mesh

2015 ◽  
Author(s):  
Alessandro Nocente ◽  
Tufan Arslan ◽  
Torbjørn K. Nielsen
Keyword(s):  
Centrifugal Pump ◽  
Turbulence Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Transient State ◽  
Computational Effort ◽  
Phase Flow ◽  
Two Phase ◽  
Ansys Fluent ◽  
Performance Report

The present work reviews a comparison between calculations of a steady and unsteady three dimensional (3D) flow past the diffuser channels of a centrifugal pump. The commercial software ANSYS Fluent has been used. The considered domain is one of the three stages, since each has exactly the same design. In the first part, simulations are carried out at the best efficiency point (BEP) both steady and transient state, single phase flow and four different turbulence models. Results are compared with the performance report from the manufacturer. In the second part, only the realizable k-ε turbulence model has been taken into account. The simulations have been repeated for different mass flows and the results were again compared with the data from the manufacturer. The comparison performed in the first part shows that integral quantities results are not sensibly influenced by the turbulence model. The comparison at different mass flow shows that the steady state simulations demonstrated to be a good approximation of the transient state, always containing the error within an acceptable limit. The minor computational effort needed makes it attractive to be used for further investigations which will involve two-phase flow studies on the same pump.

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.

Effects of Different Turbulence Models on Three-Dimensional Unsteady Cavitating Flows in the Centrifugal Pump and Performance Prediction

2019 ◽  
Vol 20 (3-4) ◽  
pp. 487-509 ◽  
Author(s):  
Ahmed Ramadhan Al-Obaidi
Keyword(s):  
Centrifugal Pump ◽  
Turbulence Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Experimental Results ◽  
Centrifugal Pumps ◽  
Operation Condition ◽  
Sst Model ◽  
And Performance ◽  
Turbulent Models

AbstractIn centrifugal pumps, it is important to select appropriate turbulence model for the numerical simulation in order to obtain reliable and accurate results. In this work, ten turbulence models in 3-D transient simulation for the centrifugal pump are chosen and compared. The pump performance is validated with experimental results. The numerical results reveal that the SST turbulence model was closer to the experimental results in predicting head. In addition, the pressure variation trend for the ten models is very similar which increases and then decreases from the inlet to outlet of the pump along the streamline. The SST k-ω model predicts the performance of the pump was more accurately than other turbulent models. Furthermore, the results also found that the error is the least at design operation condition 300(l/min), which is around 1.98 % for the SST model and 2.14 % and 2.38 % for the LES and transition omega model. Within 7.61 %, the errors at higher flow rate 350(l/min) for SST. The error for SST model is smaller as compared to different turbulent models. For the Realizable k-ɛ model, the errors fluctuate were more high than other models.

Analysis of Two-Phase Cavitating Flow with Two-Fluid Model Using Integrated Boltzmann Equations

2013 ◽  
Vol 5 (05) ◽  
pp. 607-638 ◽  
Author(s):  
Shuhong Liu ◽  
Yulin Wu ◽  
Yu Xu ◽  
Hua-Shu Dou
Keyword(s):  
Turbulence Model ◽  
Two Phase Flow ◽  
Fluid Model ◽  
Three Dimensional ◽  
Cavitating Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Pump Sump ◽  
Two Fluid Model ◽  
Two Fluid

AbstractIn the present work, both computational and experimental methods are employed to study the two-phase flow occurring in a model pump sump. The two-fluid model of the two-phase flow has been applied to the simulation of the three-dimensional cavitating flow. The governing equations of the two-phase cavitating flow are derived from the kinetic theory based on the Boltzmann equation. The isotropic RNGk — ε — kcaturbulence model of two-phase flows in the form of cavity number instead of the form of cavity phase volume fraction is developed. The RNGk—ε—kcaturbulence model, that is the RNGk — eturbulence model for the liquid phase combined with thekcamodel for the cavity phase, is employed to close the governing turbulent equations of the two-phase flow. The computation of the cavitating flow through a model pump sump has been carried out with this model in three-dimensional spaces. The calculated results have been compared with the data of the PIV experiment. Good qualitative agreement has been achieved which exhibits the reliability of the numerical simulation model.

scholarly journals Preliminary Results of Numerical Simulation of Slug Flow in a Regular T-Junction

2018 ◽  
Vol 225 ◽  
pp. 03001
Author(s):  
Minh Tran ◽  
Zeeshan Memon ◽  
William Pao ◽  
Fakhruldin M Hashim
Keyword(s):  
Slug Flow ◽  
Two Phase Flow ◽  
Separation Efficiency ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Piping System ◽  
Phase Flow ◽  
Two Phase ◽  
Ansys Fluent ◽  
System A

Excessive liquid carryover in T-junction due to splitting nature of two-phase flow causes serious issues in piping system. A three-dimensional numerical model is employed to investigate two-phase flow split behavior of slug flow in a circular-section regular T-junction with 0.0752 m diameter. The Volume of Fraction method combined with k-ε turbulence model and initial sinusoidal perturbation in ANSYS FLUENT is adopted to characterize the effect of slug flow behavior on the phase separation efficiency. The preliminary result reveals that the simulation work can study slug flow split in great detail and the slug characteristic plays an important role in understanding split behavior.

scholarly journals SedFoam-2.0: a 3-D two-phase flow numerical model for sediment transport

2017 ◽  
Vol 10 (12) ◽  
pp. 4367-4392 ◽  
Author(s):  
Julien Chauchat ◽  
Zhen Cheng ◽  
Tim Nagel ◽  
Cyrille Bonamy ◽  
Tian-Jian Hsu
Keyword(s):  
Sediment Transport ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Test Cases ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver ◽  
Transport Problems ◽  
Stress Models

Abstract. In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended from twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD (computational fluid dynamics) toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different intergranular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only), a k − ε, and a k − ω model. The numerical implementation is demonstrated on four test cases: sedimentation of suspended particles, laminar bed load, sheet flow, and scour at an apron. These test cases illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of intergranular stress and turbulence models.

scholarly journals SedFoam-2.0: a 3D two-phase flow numerical model for sediment transport

2017 ◽  
Author(s):  
Julien Chauchat ◽  
Zhen Cheng ◽  
Tim Nagel ◽  
Cyrille Bonamy ◽  
Tian-Jian Hsu
Keyword(s):  
Sediment Transport ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Solver ◽  
Dense Granular Flow ◽  
Transport Problems ◽  
Stress Models

Abstract. In this paper, a three-dimensional two-phase flow solver, SedFoam-2.0, is presented for sediment transport applications. The solver is extended upon twoPhaseEulerFoam available in the 2.1.0 release of the open-source CFD toolbox OpenFOAM. In this approach the sediment phase is modeled as a continuum, and constitutive laws have to be prescribed for the sediment stresses. In the proposed solver, two different inter-granular stress models are implemented: the kinetic theory of granular flows and the dense granular flow rheology μ(I). For the fluid stress, laminar or turbulent flow regimes can be simulated and three different turbulence models are available for sediment transport: a simple mixing length model (one-dimensional configuration only), a k-ϵ and a k-ω model. The numerical implementation is first demonstrated by two validation test cases, sedimentation of suspended particles and laminar bed-load. Two applications are then investigated to illustrate the capabilities of SedFoam-2.0 to deal with complex turbulent sediment transport problems with different combinations of inter-granular stress and turbulence models.

Numerical Simulation and Impeller Optimization of a Centrifugal Pump

2012 ◽  
Vol 472-475 ◽  
pp. 2195-2198 ◽  
Author(s):  
Shao Ping Zhou ◽  
Pei Wen Lv ◽  
Xiao Xia Ding ◽  
Yong Sheng Su ◽  
De Quan Chen
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Flow Field ◽  
Centrifugal Pump ◽  
Turbulence Model ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Three Dimensional Flow ◽  
Field Simulation ◽  
Simulation Results

The three-dimensional flow field simulation of a centrifugal pump was presented by using commercial CFD code. In order to study the most suitable turbulence model, the three known turbulence models of Standard k-ε, RNG k-ε, Realizable k-ε were applied to simulate the flow field of the MJ125-100 centrifugal pump and predict the performance of the pump. The simulation results of head and efficiency were compared with available experimental data, and the comparison showed that the result of the numerical simulation by RNG k-ε model had the best agreement. Additionally, the effect of number of blades on the efficiency of pump was studied. The number of blades was changed from 4 to 7. The results showed that the impeller with 7 blades had the highest efficiency.

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