Focusing of rarefaction wave and dynamics of cavitation zone state behind its front in two-phase cylindrical liquid layer

2019 ◽  
Vol 146 (4) ◽  
pp. 3076-3076
Author(s):  
Valeriy Kedrinskiy ◽  
Ekaterina Bolshakova - Zhuravleva
Keyword(s):  
Rarefaction Wave ◽  
Liquid Layer ◽  
Two Phase ◽  
Zone State

scholarly journals Time-resolved PIV measurements of a deflected submerged jet interacting with liquid-gas and liquid-liquid interfaces

2021 ◽  
Author(s):  
Stefan Puttinger ◽  
Mahdi Saeedipour
Keyword(s):  
Liquid Layer ◽  
Large Scale ◽  
Free Surface Flow ◽  
Industrial Applications ◽  
Liquid Pool ◽  
Surface Flow ◽  
Two Phase ◽  
Time Resolved ◽  
Submerged Jet ◽  
Major Interest

AbstractThis paper presents an experimental investigation on the interactions of a deflected submerged jet into a liquid pool with its above interface in the absence and presence of an additional lighter liquid. Whereas the former is a free surface flow, the latter mimics a situation of two stratified liquids where the liquid-liquid interface is disturbed by large-scale motions in the liquid pool. Such configurations are encountered in various industrial applications and, in most cases, it is of major interest to avoid the entrainment of droplets from the lighter liquid into the main flow. Therefore, it is important to understand the fluid dynamics in such configurations and to analyze the differences between the cases with and without the additional liquid layer. To study this problem, we applied time-resolved particle image velocimetry experiments with high spatial resolution. A detailed data analysis of a small layer beneath the interface shows that although the presence of an additional liquid layer stabilizes the oscillations of the submerged jet significantly, the amount of kinetic energy, enstrophy, and velocity fluctuations concentrated in the proximity of the interface is higher when the oil layer is present. In addition, we analyze the energy distribution across the eigenmodes of a proper orthogonal distribution and the distribution of strain and vortex dominated regions. As the main objective of this study, these high-resolution time-resolved experimental data provide a validation platform for the development of new models in the context of the volume of fluid-based large eddy simulation of turbulent two-phase flows.

scholarly journals Precise Determination of Liquid Layer Thickness with Downward Annular Two-Phase Gas-Very Viscous Liquid Flow

Energies ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 6529
Author(s):  
Krystian Czernek ◽  
Stanisław Witczak
Keyword(s):  
Viscous Liquid ◽  
Liquid Layer ◽  
Liquid Flow ◽  
Liquid Films ◽  
Measuring System ◽  
Image Analysis System ◽  
Oil Viscosity ◽  
Two Phase ◽  
Study Results

The paper presents the characteristics of the original optoelectronic system for measuring the values of hydrodynamics of two-phase downward gas-very viscous liquid flow. The measurement methods and results of the research on selected values describing gas–oil two-phase flow are presented. The study was conducted in vertical pipes with diameters of 12.5, 16, 22, and 54 mm. The research was conducted with the superficial velocities of air jg = 0–29.9 m/s and oil jl = 0–0.254 m/s, which corresponded to the values of gas stream density gg = (0–37.31) kg/(m2s) and of liquid gl = (0.61–226.87) kg/(m2s), in order to determine the influence of air and oil streams on the character of liquid films. The variations in oil viscosity were applied in the range ηl = (0.055–1.517) Pas. The study results that were obtained with optical probes along with computer image analysis system revealed vast research opportunities in terms of the identification of gas–liquid two-phase downward flow structures that were generated as well as the determination of the thickness of liquid film with various level of interfacial surface area undulation. The designed and constructed proprietary measuring system is also useful for testing the liquid layer by determining the parameters of the resulting waves. It is considered that the apparatus system that is presented in the article is the most effective in examining the properties of liquid layers of oil and other liquids with low electrical conductivity and a significant degree of monochromatic light absorption. In view of noninvasive technique of measuring characteristic values of liquid films being formed, the above measuring system is believed to be very useful for industry in the diagnostics of the apparatus employing such flows.

RELAP5 Analysis of Two-Phase Decompression and Rarefaction Wave Propagation Under a Temperature Gradient

2010 ◽  
Vol 169 (1) ◽  
pp. 34-49 ◽  
Author(s):  
Nathan Lafferty ◽  
Victor Ransom ◽  
Martin Lopez De Bertodano
Keyword(s):  
Wave Propagation ◽  
Temperature Gradient ◽  
Rarefaction Wave ◽  
Two Phase

Criteria for mucus transport in the airways by two-phase gas-liquid flow mechanism

1986 ◽  
Vol 60 (3) ◽  
pp. 901-907 ◽  
Author(s):  
C. S. Kim ◽  
C. R. Rodriguez ◽  
M. A. Eldridge ◽  
M. A. Sackner
Keyword(s):  
Layer Thickness ◽  
Liquid Layer ◽  
Liquid Flow ◽  
Critical Conditions ◽  
Airflow Rate ◽  
Tube Model ◽  
Flow Mechanism ◽  
Two Phase ◽  
Liquid Layer Thickness ◽  
Gas Liquid Flow

The critical conditions for mucous layer transport in the respiratory airways by two-phase gas-liquid flow mechanism were investigated by using 0.5- and 1.0-cm-ID tube models. Several test liquids with rheological properties comparable to human sputum were supplied continuously into the vertically positioned tube models in such a way that the liquid could form a uniform layer while traveling upward through the tube with a continuous upward airflow. The critical airflow rate and critical liquid layer thickness required for the upward transport of the liquids were determined. The critical airflow rate was in the Reynolds number (Re) range of 142–1,132 in the 0.5-cm-ID tube model and 708–2,830 in the 1.0-cm-ID tube model depending on the types of liquids tested. In both models, the critical airflow rate was lower with viscoelastic liquids than with viscous oils. The critical liquid layer thickness ranged from 0.2 to 0.5 mm in the 0.5-cm-ID tube model and 0.8 to 1.4 mm in the 1.0-cm-ID tube model at Re of 2,800. These values decreased rapidly with increasing airflow rate. The critical thickness relative to the tube diameter ranged from 3 to 15% of the respective tube diameter and was lower by approximately 30–50% in the 0.5-cm-ID tube model than in the 1.0-cm-ID tube model over the entire Re range tested. The results indicate that the critical conditions for the mucus transport by two-phase gas-liquid flow mechanism are within the range that can be achieved in patients with bronchial hypersecretions during normal breathing.

Two-phase detonation of a liquid layer.

AIAA Journal ◽  
1969 ◽  
Vol 7 (5) ◽  
pp. 859-863 ◽  
Author(s):  
K. W. RAGLAND ◽  
J. A. NICHOLL
Keyword(s):  
Liquid Layer ◽  
Two Phase

Investigation of Two-Phase Flow and Heat Transfer Inside Rotational Paper Dryers Using Three Different Multiphase Computational Models

2020 ◽  
Author(s):  
Hamed Majeed ◽  
Victor Barboza Pereira ◽  
Ting Wang ◽  
Joseph V. D’Amico ◽  
Chris Kononchek
Keyword(s):  
Heat Transfer ◽  
Mixture Model ◽  
Liquid Layer ◽  
Computational Models ◽  
Two Phase Flow ◽  
Computational Time ◽  
Phase Flow ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Vof Model

Abstract The paper industry uses cylinder dryers that employ steam to heat the paper web moving over the cylinder outer walls. As steam condenses, the condensate is accumulated inside the cylinder dryers. The condensate is evacuated using either stationary or rotary siphons. The form of condensate motion occurring inside the cylinder can be puddling, cascading or rimming depending on the size of the cylinder dryer, the rotating speed, the amount of condensate, and the surface finish of the cylinder dryer inner wall with or without ribs or grooves. The behavior of the condensate inside the cylinder dryers affects the heat transfer through the cylinder wall, the torque and power requirements of the dryer, and the performance of the condensate evacuation via siphons. To help improve the drying performance, it is important to understand the fundamental thermal-fluid physics in the rotational dryer. Thus, the objectives of this study are (a) to investigate the dynamic two-phase flow and heat transfer behavior inside the rotational paper dryer at different rotational speeds; (b) to employ three different multiphase computational models, the Volume of Fluid (VOF) model, the Mixture model, and the Eulerian-Eulerian (E-E) model, and compare their results. The results show that the E-E model better captures the physics of condensate behavior inside the dryer. It also predicts very well the rimming speed in comparison with the empirical correlation although it takes longer computational time than the VOF model. The mixture model doesn’t adequately capture the cascade and rimming physics due to excessive liquid dispersion. Based on the results, the categorization of the thermal-flow behavior of the liquid layer is expanded from the traditional three phases to five phases: puddling, transitional cascading, cascading, transitional rimming, and steady rimming. A detailed analysis of the rotating liquid layer behavior and its corresponding wall heat transfer passing through each phase is presented. Generally, the heat transfer increases during the initial puddling period, followed by oscillatory attenuation during the cascade period, finally reaches steady state after rimming is achieved.

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