Cavitating Flow of Liquid Nitrogen in Horizontal Rectangular Nozzle

2003 ◽  
Author(s):  
Jun Ishimoto ◽  
Masahiro Onishi ◽  
Takashi Tokumasu ◽  
Kenjiro Kamijo
Keyword(s):  
Liquid Nitrogen ◽  
High Performance ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Cavitating Flow ◽  
Two Phase ◽  
Cloud Cavitation ◽  
Rectangular Nozzle ◽  
Thermodynamic Effect ◽  
Two Fluid Model

The fundamental characteristics of the two-dimensional cavitating flow of liquid nitrogen through a horizontal rectangular nozzle are numerically and experimentally investigated to realize the further development and high performance of new multiphase cryogenic fluid applications. First, the governing equations of the cavitating flow of liquid nitrogen based on the unsteady thermal nonequilibrium two-fluid model are presented, and several flow characteristics are numerically calculated, taken into account the thermodynamic effect of cryogenic conditions. Next, the flow visualization measurement on unsteady cavitating flow of liquid nitrogen through a rectangular nozzle installed in a horizontal duct is carried out to clarify the basic cryogenic two-phase flow structure and fundamental characteristics of the transient growth process of cryogenic cloud cavitation.

Numerical and Experimental Study on the Cavitating Flow Characteristics of Pressurized Liquid Nitrogen in a Horizontal Rectangular Nozzle

2004 ◽  
Vol 127 (4) ◽  
pp. 515-524 ◽  
Author(s):  
Jun Ishimoto ◽  
Masahiro Onishi ◽  
Kenjiro Kamijo
Keyword(s):  
Experimental Study ◽  
Gas Phase ◽  
Liquid Nitrogen ◽  
Cooling System ◽  
Continuous Process ◽  
Cavity Growth ◽  
Flow Characteristics ◽  
Cavitating Flow ◽  
Rectangular Nozzle ◽  
Thermodynamic Effect

The thermodynamic effect on cryogenic cavitating flow characteristics of pressurized liquid nitrogen in a horizontal rectangular nozzle is precisely investigated by numerical analysis based on an unsteady thermal nonequilibrium two-fluid model and by flow visualization measurement. According to the numerical and experimental study, the sufficiently useful results are proposed to realize the further development and high performance of a type of cryogenic two-phase cooling system. It is numerically and experimentally found that the inception of cryogenic cavitation occurs and the cavity grows in the vicinity of the wall surface of the inlet throat section. It is also found that the continuous process and behavior of cavitation inception, cloud cavity growth, and gas phase diffusion behavior with time in pressurized liquid nitrogen are dominated not only by several additional forces in the gas-phase momentum equation, but also by the thermodynamic effect that acts on the cavitation bubbles due to the inherent properties of cryogenic fluid. Especially under conditions of the same temperature and same aspect ratio of the cloud cavity, similar generating behavior of cavitation can be often found in the high Reynolds number region in spite of large cavitation number.

Cavitating Flow Simulation in a Closed Pump Sump by Two-Fluid Model and Its PIV Verification

2003 ◽  
Author(s):  
Yu Xu ◽  
Yulin Wu ◽  
Shuhong Liu ◽  
Yong Li
Keyword(s):  
Fluid Model ◽  
Flow Simulation ◽  
Cavitating Flow ◽  
Governing Equations ◽  
Two Phase ◽  
Averaged Equations ◽  
Flow Through ◽  
Pump Sump ◽  
Two Fluid Model ◽  
Two Fluid

In this paper, the two-fluid model was adopted to analyze the cavitating flow. Based on Boltzmann equation, governing equations for two-phase cavitating flow were obtained by using the microscopic kinetic theory, in which the equation terms for mass and momentum transportations can be obtained directly. Then the RNG k–ε–kg turbulence model, that is RNG k–ε model for the liquid phase and kg model for the cavity phase, was used to close the Reynolds time-averaged equations. According to the governing equations above, the simulation of the two-phase cavitating flow through a closed pump sump has been carried out. The calculated results have been compared with a PIV experiment. Good agreement exhibited.

scholarly journals A Two-Fluid Model for High Viscosity Upward Annular Flow in Vertical Pipes

2021 ◽  
Author(s):  
Joseph X. F. Ribeiro ◽  
Ruiquan Liao ◽  
Aliyu M. Aliyu ◽  
Salem K. B. Ahmed ◽  
Yahaya D. Baba ◽  
...  
Keyword(s):  
Fluid Model ◽  
Accurate Determination ◽  
Flow Characteristics ◽  
High Viscosity ◽  
Two Phase ◽  
Friction Factors ◽  
Two Fluid Model ◽  
Two Fluid ◽  
Selection Of

Selection of appropriate friction factors is paramount for accurate prediction of key flow characteristics in gas–liquid two-phase flows. In this work, experimental investigation of vertical air and oil (with viscosities up to 200 mPa s) flow in a 0.060-m ID pipe is reported. Superficial air and oil velocity ranges utilized are from 22.37 to 59.06 m/s and 0.05 to 0.16 m/s respectively. The influence of estimation of interfacial friction factor on accurate determination of film thickness, void fraction and pressure gradient was investigated using a two-fluid model. The results indicated that the two-fluid model is capable of accurately predicting flow characteristics. Further, it reveals that the best performing correlations are the Belt et al. and Ambrosini et al. correlations.

CFD Studies on the Heat Transfer Characteristics of a Horizontal Single-Tube in Fluidized Bed Heat Exchanger

2011 ◽  
Vol 374-377 ◽  
pp. 183-186
Author(s):  
Cong Shen ◽  
Jian Xiang Guo ◽  
Lin Li ◽  
Jin Fei Sun
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Fluidized Bed ◽  
High Performance ◽  
Fluid Model ◽  
Two Phase ◽  
Scaling Properties ◽  
Single Tube ◽  
Industrial Sectors ◽  
Two Fluid Model

The fluidized-bed heat exchanger is widely used in various industrial sectors with the high performance of its heat transfer, ability to adapt working conditions, anti-scaling properties and many other advantages. This paper takes a horizontal single-tube in fluidized-bed heat exchanger and the fluidized low-temperature smoke around the tube as the objects of study. Euler-Euler two-fluid model is taken in use. Heat transfer between gas-solid two-phase flows and water in single-tube is simulated. The temperature field and general heat transfer coefficient is analyzed by simulated graphics.

scholarly journals A Two-Fluid Model for High-Viscosity Upward Annular Flow in Vertical Pipes

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3485
Author(s):  
Joseph X. F. Ribeiro ◽  
Ruiquan Liao ◽  
Aliyu M. Aliyu ◽  
Salem K. B. Ahmed ◽  
Yahaya D. Baba ◽  
...  
Keyword(s):  
Pressure Gradient ◽  
Friction Factor ◽  
Fluid Model ◽  
Flow Characteristics ◽  
Interfacial Friction ◽  
Internal Diameter ◽  
Liquid Viscosity ◽  
Two Phase ◽  
Two Fluid Model ◽  
Two Fluid

Proper selection and application of interfacial friction factor correlations has a significant impact on prediction of key flow characteristics in gas–liquid two-phase flows. In this study, experimental investigation of gas–liquid flow in a vertical pipeline with internal diameter of 0.060 m is presented. Air and oil (with viscosities ranging from 100–200 mPa s) were used as gas and liquid phases, respectively. Superficial velocities of air ranging from 22.37 to 59.06 m/s and oil ranging from 0.05 to 0.16 m/s were used as a test matrix during the experimental campaign. The influence of estimates obtained from nine interfacial friction factor models on the accuracy of predicting pressure gradient, film thickness and gas void fraction was investigated by utilising a two-fluid model. Results obtained indicate that at liquid viscosity of 100 mPa s, the interfacial friction factor correlation proposed by Belt et al. (2009) performed best for pressure gradient prediction while the Moeck (1970) correlation provided the best prediction of pressure gradient at the liquid viscosity of 200 mPa s. In general, these results indicate that the two-fluid model can accurately predict the flow characteristics for liquid viscosities used in this study when appropriate interfacial friction factor correlations are implemented.

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 Natural modes of the two-fluid model of two-phase flow

2021 ◽  
Vol 33 (3) ◽  
pp. 033324
Author(s):  
Alejandro Clausse ◽  
Martín López de Bertodano
Keyword(s):  
Two Phase Flow ◽  
Fluid Model ◽  
Phase Flow ◽  
Two Phase ◽  
Natural Modes ◽  
Two Fluid Model ◽  
Two Fluid

Two-Phase Flows in Mini-/Micro-Gas Flow Channels of PEM Fuel Cells

2013 ◽  
Author(s):  
Sung Chan Cho ◽  
Yun Wang
Keyword(s):  
Pressure Drop ◽  
Gas Flow ◽  
Fluid Model ◽  
Pem Fuel Cells ◽  
Two Phase ◽  
Micro Gas Flow ◽  
Two Fluid Model ◽  
The Impact ◽  
Two Fluid ◽  
Phase Pressure

In this paper, two-phase flow dynamics in a micro channel with various wall conditions are both experimentally and theoretically investigated. Annulus, wavy and slug flow patterns are observed and location of liquid phase on different wall condition is visualized. The impact of flow structure on two-phase pressure drop is explained. Two-phase pressure drop is compared to a two-fluid model with relative permeability correlation. Optimization of correlation is conducted for each experimental case and theoretical solution for the flows in a circular channel is developed for annulus flow pattern showing a good match with experimental data in homogeneous channel case.

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