Numerical investigations of turbulent single-phase and two-phase flows in a diffuser

Kopparthy, Saketh; Mansour, Michael; Janiga, Gábor

doi:10.1016/j.ijmultiphaseflow.2020.103333

Cited by 20 publications

(11 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Pineda et al (2016) and Zhu et al (2019) investigated the two-phase flow patterns in ESP using VOF methods and compared them to experimental data. Mansour et al (2020aMansour et al ( , 2020b, Kopparthy et al (2020), and Parikh et al (2020) employed VOF methods on the same test cases, i.e., diffuser and research pump flow, investigated in the present study, figured out important physical mechanisms of attenuating pump performance, and the beneficial effect of an inducer (Mansour et al, 2020a(Mansour et al, , 2020b. However, it remains unclear if the spatial resolution limit allows a sufficient resolution of void structures within the VOF simulations.…”

Section: Latin Symbols Bmentioning

confidence: 68%

“…Thus, the turbulence model and particular consideration of un-isotropy rather than the bubble diameter or polydispersity seems to be the key to reproduce the main flow pattern in terms of gas cavity size. It is interesting to note that Kopparthy et al (2020) obtained a distinctive gas accumulation even by utilizing the linear k- model for the simulation of the same diffuser test case. A VOF method rather than a disperse multi-fluid model has been utilized by Kopparthy et al (2020) so that it can be assumed that the turbulence model performance is closely associated with the particular multi-phase model it is combined with.…”

Section: Turbulence Model Variationmentioning

confidence: 89%

“…The cross-section geometry is rectangular and, therefore, symmetric around the horizontal as well as vertical axis. Nonetheless, in Kopparthy et al (2020), the entire cross-section was included in the computational domain, and a significantly asymmetric flow field within the cross-section was obtained even for steady-state simulations despite a perfectly symmetric grid topology and sufficient solver convergence. Thus, to circumvent artificial flow field asymmetries, only one quadrant of the computational domain is considered for single-phase flow simulations in the present study, applying symmetry boundary conditions.…”

Section: Diffusermentioning

confidence: 99%

See 2 more Smart Citations

3D simulation of gas-laden liquid flows in centrifugal pumps and the assessment of two-fluid CFD methods

Hundshagen

Mansour

Skoda

2020

Exp. Comput. Multiph. Flow

Self Cite

View full text Add to dashboard Cite

An assessment of a two-fluid model assuming a continuous liquid and a dispersed gas phase for 3D computational fluid dynamics (CFD) simulations of gas/liquid flow in a centrifugal research pump is performed. A monodisperse two-fluid model, in conjunction with a statistical eddy-viscosity turbulence model, is utilized. By a comprehensive measurement database, a thorough assessment of model inaccuracies is enabled. The results on a horizontal diffuser flow reveal that the turbulence model is one main limitation of simulation accuracy for gas/liquid flows. Regarding pump flows, distinctions of single-phase and two-phase flow in a closed and semi-open impeller are figured out. Even single-phase flow simulations reveal challenging requirements on a high spatial resolution, e.g., of the rounded blade trailing edge and the tip clearance gap flow. In two-phase pump operation, gas accumulations lead to coherent gas pockets that are predicted partly at wrong locations within the blade channel. At best, a qualitative prediction of gas accumulations and the head drop towards increasing inlet gas volume fractions (IGVF) can be obtained. One main limitation of two-fluid methods for pump flow is figured out in terms of the violation of the dilute, disperse phase assumption due to locally high disperse phase loading within coherent gas accumulations. In these circumstances, bubble population models do not appear beneficial compared to a monodisperse bubble distribution. Volume-of-Fluid (VOF) methods may be utilized to capture the phase interface at large accumulated gas cavities, requiring a high spatial resolution. Thus, a hybrid model, i.e., a dispersed phase two-fluid model including polydispersity for flow regions with a dilute gas phase, should be combined with an interphase capturing model, e.g., in terms of VOF. This hybrid model, together with scale-resolving turbulence models, seems to be indispensable for a quantitative two-phase pump performance prediction.

show abstract

Section: Latin Symbols Bmentioning

confidence: 68%

Section: Turbulence Model Variationmentioning

confidence: 89%

Section: Diffusermentioning

confidence: 99%

See 1 more Smart Citation

3D simulation of gas-laden liquid flows in centrifugal pumps and the assessment of two-fluid CFD methods

Hundshagen

Mansour

Skoda

2020

Exp. Comput. Multiph. Flow

Self Cite

View full text Add to dashboard Cite

show abstract

“…Owing to the turbulent flow within the water diffuser, a K-ε model of turbulence is employed in this study. Base on the published work regarding water diffusers [29], the complete mathematical model equations of the model are provided as follows.…”

Section: Model Assumptions and Governing Equationsmentioning

confidence: 99%

Numerical Simulation on the Structural Design of a Multi-Pore Water Diffuser during the External Ice Melting Process of an Ice Storage System

et al. 2022

Energies

View full text Add to dashboard Cite

A water diffuser is a critical auxiliary equipment for an ice storage system during the external ice melting process. This paper proposes a linear multi-pore water diffuser for an ice storage system with 500 t of refrigeration capacity to enhance the performance of external ice melting. By establishing a three-dimensional two-phase volume of fluid (VOF) model, different structural designs of water diffusers for the ice storage device are numerically examined regarding the degree of turbulence, flow velocity, and pressure drop. The results show that the optimal water diffuser with five rows of trunk pipe and six perforated pores arranged in per row of branch pipe with a 4mm diameter of perforated pores exhibiting a relatively lower degree of turbulence with a lower pressure drop compared with the other designs in this study. Meanwhile, the influence of the flow velocity on the ice melting process is also investigated by a numerical model of ice melting. It is found that the fed flow velocity from the main pipe inlet exhibits a great impact on the external ice melting process. Compared with the external ice melting process without the water diffuser, the external ice melting process with optimal water diffuser design under flow velocity of 1.0 m s−1 could shorten the overall ice-melting time by 16 h. Additionally, through adjusting the water flow velocity, different output cooling can be realized to provide a fast response speed to the cooling variations in demand of the terminal users with a reduced cost.

show abstract

“…Due to the existence of various equations and parameters governing such high velocity and aeration flows, their numerical analysis is not possible, and in most cases to solve many problems related to hydraulics, such flows have to use hypotheses and simplifications. We are the ones who make the results differ from reality [12].…”

Section: Introductionmentioning

confidence: 97%

Systematic Investigation of two-Phase Flow in Special Channels

Kuzichkin¹,

Ali²,

Alkaim³

et al. 2022

Fluid Dynamics &Amp; Materials Processing

View full text Add to dashboard Cite

A systematic study of two-phase (water-air) currents in open channels (water-air) has been conducted by means of experiments and numerical simulations. A dedicated device has been designed and manufactured on purpose. The numerical simulations have been based on the solution of a system of mass, momentum and energy balance equations for a two-phase fluid. The effect of different influential parameters has been explored, namely, velocity and dimensions of the channel, surface pressure and tension.

show abstract

Numerical investigations of turbulent single-phase and two-phase flows in a diffuser

Cited by 20 publications

References 57 publications

3D simulation of gas-laden liquid flows in centrifugal pumps and the assessment of two-fluid CFD methods

3D simulation of gas-laden liquid flows in centrifugal pumps and the assessment of two-fluid CFD methods

Numerical Simulation on the Structural Design of a Multi-Pore Water Diffuser during the External Ice Melting Process of an Ice Storage System

Systematic Investigation of two-Phase Flow in Special Channels

Contact Info

Product

Resources

About