scholarly journals Numerical Study on the Tandem Submerged Hydrofoils Using RANS Solver

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Moloud Arian Maram ◽  
Hamid Reza Ghafari ◽  
Hassan Ghassemi ◽  
Mahmoud Ghiasi
Keyword(s):  
Drag Coefficient ◽  
Single Phase ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Lower Surface ◽  
Phase Flow ◽  
Two Phase ◽  
Hydrodynamic Coefficient ◽  
Ansys Fluent

This paper is presented on the tandem two-dimensional hydrofoils with profiles NACA4412 in single-phase and two-phase flow domains for different submergence depths and different distances in a various angle of attack (AoA). Also, supercavitation is studied at σ = 0.34 by the Zwart cavitation model. Reynolds-averaged Navier–Stokes (RANS) with the shear stress transport (SST) K-ω is employed as a turbulence model in transient analysis of Ansys FLUENT software. The numerical results show that, by increasing depth, the drag coefficient increases for both hydrofoils 1 and 2 as well as the lift coefficient. The drag coefficient of hydrofoil 2 is bigger than hydrofoil 1 for all depths; moreover, it was found that the flow pressure behind the hydrofoil 1 had affected the upper and the lower surface of the hydrofoil 2 at each distance or AoA. These effects are observed in the hydrofoil 2 lift coefficient as well as the flow separation. However, the maximum lift-to-drag ratio is observed at AoA =  8 ° and 3.5c distance. Also, single-phase results reveal that the value of pressure and the hydrodynamic coefficient are very different from the two-phase flow results, due to the elimination of the free surface. So, a two-phase flow domain is recommended for increasing the accuracy of results. In addition, the investigation of supercavitation shows a growth in cavity occurrence on the surface by raising AoA.

Numerical Study of the Single-Phase and Two-Phase Flow in a Centrifugal Pump

2013 ◽  
Vol 307 ◽  
pp. 215-218
Author(s):  
Te Ba ◽  
Arthur Teck Bin Lim ◽  
Chang Wei Kang
Keyword(s):  
Centrifugal Pump ◽  
Single Phase ◽  
Transient Flow ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Flow Simulation ◽  
Phase Flow ◽  
Two Phase ◽  
Normal Mass ◽  
Phase Water

The paper presents the numerical investigation of a radial flow centrifugal pump with 2D curvature blade geometry. The geometry is based on the experimental equipment by Anagostopulos. Single phase (water) flow is modeled with a normal mass flow rate and rotation speed. Pressure distribution and fluid streamlines are evaluated and visualized. An extension of the model to transient flow and two-phase flow simulation has been done to see the effect of impeller rotation and gas entrainment in the centrifugal operation procedure.

scholarly journals A Numerical study of Two-Phase flow through a Rectangular Duct with a Convergence Ribs

2018 ◽  
Vol 7 (4.19) ◽  
pp. 969
Author(s):  
Riyadh. S.Al-Turaihi ◽  
Abbas Sahi Shareef ◽  
Ali Abdalaimma
Keyword(s):  
Pressure Drop ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Three Dimensional ◽  
Pressure Profile ◽  
Phase Flow ◽  
Three Dimensional Model ◽  
Test Channel ◽  
Two Phase ◽  
Ansys Fluent

Two-phase flow in ribbed convergent rectangular upward vertical duct was studied.Water and air were usedas materials for two-phase. Numerical studies have been performed to test the influence of increased air and water discharges on the pressure profile and pressure drop through the convergent section, as the effect of increasing the convergent angle on the pressure difference across the convergent section was studied.Water inlet discharges used were between (5-20 L/min), and air discharges were between (5.833-16.666 L/min). Two test channels with convergent angles (10 and 15 degrees) were used.Computational fluid dynamics for a three-dimensional model was simulated with ANSYS fluent 18 depending on the boundary condition and governed by equations of Eulerian multiphase flow model.The results indicated that the pressure along the test channel raises as water and air discharge rise. It was observedtoo the pressure drop increases with the increase of the convergence angle.  

Numerical study on two-phase flow through fractured porous media

2011 ◽  
Vol 54 (9) ◽  
pp. 2412-2420 ◽  
Author(s):  
ZhaoQin Huang ◽  
Jun Yao ◽  
YueYing Wang ◽  
Ke Tao
Keyword(s):  
Porous Media ◽  
Two Phase Flow ◽  
Numerical Study ◽  
Fractured Porous Media ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Through

Experimental Study on Heat Transfer of Single-Phase Flow and Boiling Two-Phase Flow in Vertical Narrow Annuli

2002 ◽  
Author(s):  
Suizheng Qiu ◽  
Minoru Takahashi ◽  
Guanghui Su ◽  
Dounan Jia
Keyword(s):  
Heat Transfer ◽  
Single Phase ◽  
Two Phase Flow ◽  
Annular Channel ◽  
Phase Flow ◽  
Single Phase Flow ◽  
Transfer Coefficients ◽  
Two Phase ◽  
Narrow Annuli ◽  
Narrow Gaps

Water single-phase and nucleate boiling heat transfer were experimentally investigated in vertical annuli with narrow gaps. The experimental data about water single-phase flow and boiling two-phase flow heat transfer in narrow annular channel were accumulated by two test sections with the narrow gaps of 1.0mm and 1.5mm. Empirical correlations to predict the heat transfer of the single-phase flow and boiling two-phase flow in the narrow annular channel were obtained, which were arranged in the forms of the Dittus-Boelter for heat transfer coefficients in a single-phase flow and the Jens-Lottes formula for a boiling two-phase flow in normal tubes, respectively. The mechanism of the difference between the normal channel and narrow annular channel were also explored. From experimental results, it was found that the turbulent heat transfer coefficients in narrow gaps are nearly the same to the normal channel in the experimental range, and the transition Reynolds number from a laminar flow to a turbulent flow in narrow annuli was much lower than that in normal channel, whereas the boiling heat transfer in narrow annular gap was greatly enhanced compared with the normal channel.

Modeling of Sodium Two-Phase Flow With the TRACE Code

2009 ◽  
Author(s):  
Aurelia Chenu ◽  
Konstantin Mikityuk ◽  
Rakesh Chawla
Keyword(s):  
Single Phase ◽  
Two Phase Flow ◽  
Flow Simulation ◽  
Phase Flow ◽  
Fluid Models ◽  
Code System ◽  
Two Phase ◽  
Liquid Flows ◽  
Transfer Mechanisms ◽  
Two Fluid

In the framework of PSI’s FAST code system, the TRACE thermal-hydraulics code is being extended for representation of sodium two-phase flow. As the currently available version (v.5) is limited to the simulation of only single-phase sodium flow, its applicability range is not enough to study the behavior of a Sodium-cooled Fast Reactor (SFR) during a transient in which boiling is anticipated. The work reported here concerns the extension of the two-fluid models, which are available in TRACE for steam-water, to sodium two-phase flow simulation. The conventional correlations for ordinary gas-liquid flows are used as basis, with optional correlations specific to liquid metal when necessary. A number of new models for representation of the constitutive equations specific to sodium, with a particular emphasis on the interfacial transfer mechanisms, have been implemented and compared with the original closure models. As a first application, the extended TRACE code has been used to model experiments that simulate a loss-of-flow (LOF) accident in a SFR. The comparison of the computed results, with both the experimental data and SIMMER-III code predictions, has enabled validation of the capability of the modified TRACE code to predict sodium boiling onset, flow regimes, dryout, flow reversal, etc. The performed study is a first-of-a-kind application of the TRACE code to two-phase sodium flow. Other integral experiments are planned to be simulated to further develop and validate the two-phase sodium flow methodology.

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

Processes ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 330 ◽  
Author(s):  
Chuan Wang ◽  
Bo Hu ◽  
Yong Zhu ◽  
Xiuli Wang ◽  
Can Luo ◽  
...  
Keyword(s):  
Centrifugal Pump ◽  
Two Phase Flow ◽  
Numerical Study ◽  
The Self ◽  
Main Stage ◽  
Phase Flow ◽  
Urban Greening ◽  
Two Phase ◽  
Ansys Cfx ◽  
Priming Process

A self-priming centrifugal pump can be used in various areas such as agricultural irrigation, urban greening, and building water-supply. In order to simulate the gas-water two-phase flow in the self-priming process of a self-priming centrifugal pump, the unsteady numerical calculation of a typical self-priming centrifugal pump was performed using the ANSYS Computational Fluid X (ANSYS CFX) software. It was found that the whole self-priming process of a self-priming pump can be divided into three stages: the initial self-priming stage, the middle self-priming stage, and the final self-priming stage. Moreover, the self-priming time of the initial and final self-priming stages accounts for a small percentage of the whole self-priming process, while the middle self-priming stage is the main stage in the self-priming process and further determines the length of the self-priming time.

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