scholarly journals B8.2 - Simultaneous Measurements of the Liquid Phase Velocity and Gas Bubble Trajectories in a Two-Phase Flow at Gas- Evolving Electrodes

2015 ◽  
Author(s):  
D. Baczyzmalski ◽  
C. J. Kähler ◽  
C. Cierpka ◽  
T. Weier
Keyword(s):  
Liquid Phase ◽  
Phase Velocity ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Gas Bubble ◽  
Two Phase ◽  
Simultaneous Measurements

Two-phase flow regime identification based on the liquid-phase velocity information and machine learning

2020 ◽  
Vol 61 (10) ◽  
Author(s):  
Yongchao Zhang ◽  
Amirah Nabilah Azman ◽  
Ke-Wei Xu ◽  
Can Kang ◽  
Hyoung-Bum Kim
Keyword(s):  
Machine Learning ◽  
Liquid Phase ◽  
Phase Velocity ◽  
Flow Regime ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Regime Identification ◽  
Velocity Information

On the performance of a cascade of turbine rotor tip section blading in wet steam Part 3: Wake traverses

1997 ◽  
Vol 211 (8) ◽  
pp. 639-648 ◽  
Author(s):  
F Bakhtar ◽  
H Mashmoushy ◽  
O C Jadayel
Keyword(s):  
Liquid Phase ◽  
Two Phase Flow ◽  
Turbine Rotor ◽  
Phase Flow ◽  
Wet Steam ◽  
Flow Conditions ◽  
Two Phase ◽  
Blow Down ◽  
The Third ◽  
Phase Mixture

During the course of expansion of steam in turbines the fluid first supercools and then nucleates to become a two-phase mixture. The liquid phase consists of a large number of extremely small droplets which are difficult to generate except by nucleation. To reproduce turbine two-phase flow conditions requires a supply of supercooled vapour which can be achieved under blow-down conditions by the equipment employed. This paper is the third of a set describing an investigation into the performance of a cascade of rotor tip section profiles in wet steam and presents the results of the wake traverses.

Analysis of Two-Phase Flow Slug Regime With Engineering Approach

2018 ◽  
Author(s):  
Nariman Ashrafi ◽  
Armin Chegini ◽  
Ali Sadeghi
Keyword(s):  
Liquid Phase ◽  
Velocity Gradient ◽  
Two Phase Flow ◽  
Back Pressure ◽  
Phase Flow ◽  
Two Phase ◽  
Engineering Approach ◽  
Basic Physics

In this research, the two-phase slug regime is investigated analytically with an engineering approach. due to the velocity gradient in the layers of the two-phase flow, numbers of waves form and grow in the liquid phase and may block the duct which in this case is called slug. Blocking the flow, it causes higher pressure accumulation which is the main reason of slug’s momentum through the duct. Simplifying the slug’s geometry and using basic physics laws yielded an equation between the slug’s back pressure and its length.

Effect of Rheological Properties of Yield Pseudoplastic Fluids on Slugs Characteristics in an Upward Vertical Pipe: Experiments and Modeling

2020 ◽  
Author(s):  
Abdalsalam Ihmoudah ◽  
Mohamed M. Awad ◽  
Mohammad Azizur Rahman ◽  
Stephen D. Butt
Keyword(s):  
Liquid Phase ◽  
Rheological Properties ◽  
Numerical Investigation ◽  
Two Phase Flow ◽  
Immiscible Fluids ◽  
Newtonian Fluids ◽  
Phase Flow ◽  
Vertical Pipe ◽  
Two Phase ◽  
Pseudoplastic Fluids

Abstract Two-phase flow of gas/yield Pseudoplastic fluids can be found in different industrial applications like the chemical processes, oil industry, and petroleum transport in pipelines. In this study, experimental and numerical investigation of the influence of Rheological properties of non-Newtonians fluids in two-phase flow (gas/yield Pseudoplastic fluids) on slug characteristics in an upward vertical flow were performed. Different concentrations of Xanthan gum solutions (0.05%, 0.10%, and 0.15%, by w/w), which are referred to as non-Newtonian, yield Pseudoplastic behavior used as the working liquids and air as a gas. The experiments were conducted in an open-loop re-circulating system has a total length of 65 m to ensure phase mixing, and authorize flow regime patterns to develop. The vertical pipe has a diameter of 76.3 mm. API-compliant 8-speed rotational viscometer model 800 was used to measure the rheological properties of non-Newtonian fluids. Flow visualization and recording videos were achieved by A high-speed camera to a comparison between behavior of Newtonian and non-Newtonian fluids in the two-phase model. Pressure transducers used to measure high-response pressure. Computational fluid dynamics software (ANSYS fluent 2019 R3) was used for the numerical investigation. The volume of fluid (VOF) model has been chosen for tracking immiscible fluids. CFD simulation results compared to the experimental data. The slug behavior and shape were noticed to be affected by changing the rheological properties of the liquid phase. with increasing XG concentration at the same operations conditions, we found that non-uniform and random distribution of small bubbles due to the effective viscous force of a liquid phase.

scholarly journals A Second-Order Turbulence Model Based on a Reynolds Stress Approach for Two-Phase Flow—Part I: Adiabatic Cases

2009 ◽  
Vol 2009 ◽  
pp. 1-14 ◽  
Author(s):  
S. Mimouni ◽  
F. Archambeau ◽  
M. Boucker ◽  
J. Laviéville ◽  
C. Morel
Keyword(s):  
Liquid Phase ◽  
Reynolds Stress ◽  
Turbulence Model ◽  
Two Phase Flow ◽  
Turbulence Modeling ◽  
Transport Model ◽  
Phase Flow ◽  
Two Phase ◽  
Model Based ◽  
Reynolds Stress Transport Model

In our work in 2008, we evaluated the aptitude of the code Neptune_CFD to reproduce the incidence of a structure topped by vanes on a boiling layer, within the framework of the Neptune project. The objective was to reproduce the main effects of the spacer grids. The turbulence of the liquid phase was modeled by a first-orderK-εmodel. We show in this paper that this model is unable to describe the turbulence of rotating flows, in accordance with the theory. The objective of this paper is to improve the turbulence modeling of the liquid phase by a second turbulence model based on aRij-εapproach. Results obtained on typical single-phase cases highlight the improvement of the prediction for all computed values. We tested the turbulence modelRij-εimplemented in the code versus typical adiabatic two-phase flow experiments. We check that the simulations with the Reynolds stress transport model (RSTM) give satisfactory results in a simple geometry as compared to aK-εmodel: this point is crucial before calculating rod bundle geometries where theK-εmodel may fail.

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