scholarly journals Floating Ice Transport Conditions at the Cross-Sections Between Pier Columns in Open Ice-Water Two-Phase Flow Canals

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1813
Author(s):  
Xiangpeng Mu ◽  
Juan Bao ◽  
Yunfei Chen
Keyword(s):  
Cross Sections ◽  
Empirical Equation ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Hydraulic Conditions ◽  
Ice Conditions ◽  
The Cross ◽  
Pass Through ◽  
Ice Water

Floating ice is easy to jam at the cross-sections contracted by bridge pier, gate pier, etc., in ice-water two-phase flow canals. To solve the problem, the critical hydraulic conditions of floating ice transport at the cross-sections between pier columns were explored in this study. Based on the generalized physical model of the cross-sections between pier columns of water transfer canals, the movement and transport characteristics of floating ice in front of the pier columns were studied under different hydraulic conditions and ice conditions, and the critical hydraulic conditions necessary for floating ice to pass through the cross-sections between pier columns were analyzed. Moreover, dimensional analysis and regression analysis were carried out in order to establish an empirical equation for calculating the critical water flow Fr (Froude number) for the floating ice to be transported through the cross-sections between pier columns, thus providing a basis for the ice jam risk assessment and hydraulic regulation of ice-water two-phase flow canals, as well as control of the emergent ice drainage of canals during freezing periods.

Note on Relationships between Friction and Liquid Cross-Sections during Two-Phase Flow

1966 ◽  
Vol 8 (1) ◽  
pp. 107-109 ◽  
Author(s):  
D. Chisholm
Keyword(s):  
Pressure Gradient ◽  
Cross Section ◽  
Cross Sections ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Pronounced Change ◽  
Two Phase ◽  
Horizontal Tubes ◽  
A Value ◽  
Friction Pressure

Relationships between the friction pressure gradient and the cross-section of the tube occupied by the liquid are developed for the flow of air-water mixtures in rough-walled horizontal tubes. The data indicate a pronounced change in the form of the relationships when the pressure gradient reaches a value of about 60 lb/ft2ft.

Phase Distribution Mechanisms in Turbulent Two-Phase Flow in Channels of Arbitrary Cross Section

1981 ◽  
Vol 103 (4) ◽  
pp. 583-589 ◽  
Author(s):  
D. A. Drew ◽  
R. T. Lahey
Keyword(s):  
Cross Sections ◽  
Two Phase Flow ◽  
Phase Distribution ◽  
Bubbly Flow ◽  
Arbitrary Cross Section ◽  
Phase Flow ◽  
Two Phase ◽  
Void Distribution ◽  
Special Case ◽  
Turbulent Two Phase Flow

An analytical model for the phase distribution mechanisms in fully developed turbulent two-phase flow in channels of arbitrary cross sections has been derived. The model has been applied to the special case of cylindrical pipe flow, and compared with existing data. It has been found that, for bubbly flow, it is the distribution of the liquid phase turbulence which determines the void distribution. Furthermore, the void distribution depends on the anisotropic nature of the turbulent two-phase flow.

scholarly journals Control-volume-based model of the steam-water injector flow

2010 ◽  
Vol 31 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Roman Kwidziński
Keyword(s):  
Cross Sections ◽  
Two Phase Flow ◽  
Control Volume ◽  
Outlet Temperature ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Parameters ◽  
Mixing Chamber ◽  
Wave Region ◽  
Water Nozzle

Control-volume-based model of the steam-water injector flow The paper presents equations of a mathematical model to calculate flow parameters in characteristic cross-sections in the steam-water injector. In the model, component parts of the injector (steam nozzle, water nozzle, mixing chamber, condensation wave region, diffuser) are treated as a series of connected control volumes. At first, equations for the steam nozzle and water nozzle are written and solved for known flow parameters at the injector inlet. Next, the flow properties in two-phase flow comprising mixing chamber and condensation wave region are determined from mass, momentum and energy balance equations. Then, water compression in diffuser is taken into account to evaluate the flow parameters at the injector outlet. Irreversible losses due to friction, condensation and shock wave formation are taken into account for the flow in the steam nozzle. In two-phase flow domain, thermal and mechanical nonequilibrium between vapour and liquid is modelled. For diffuser, frictional pressure loss is considered. Comparison of the model predictions with experimental data shows good agreement, with an error not exceeding 15% for discharge (outlet) pressure and 1 K for outlet temperature.

An Experimental Study With Minimum Transport Velocity of Dilute Gas-Solid Two-Phase Flow in a Vertical Pipe

2003 ◽  
Author(s):  
Mitsuaki Ochi ◽  
Hiroshi Nishimura ◽  
Masahiro Takei
Keyword(s):  
Empirical Equation ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Vertical Pipe ◽  
Air Velocity ◽  
Two Phase ◽  
Dilute Gas ◽  
Transport Velocity ◽  
Transport Experiment ◽  
Minimum Velocity

A simple empirical equation of the minimum transport velocity of a dilute two-phase flow for granular solids in a vertical pipe has been derived on the basis of both a dynamic model equation and the transport experiment. The minimum transport velocity means here the limiting air velocity at which conveying is possible in a state in which particles are not stagnant or recircular in the pipe. As a result, it is found that the empirical equation of the minimum transport velocity, simply called the minimum velocity, can arrange the data of this study with a pretty good accuracy.

scholarly journals Proppant Transportation in Cross Fractures: Some Findings and Suggestions for Field Engineering

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4912
Author(s):  
Yan Zhang ◽  
Xiaobing Lu ◽  
Xuhui Zhang ◽  
Peng Li
Keyword(s):  
Two Phase Flow ◽  
Volume Fraction ◽  
Fracture Network ◽  
Hydraulic Fractures ◽  
Phase Flow ◽  
Relative Width ◽  
Two Phase ◽  
Secondary Fracture ◽  
Dimensionless Parameters ◽  
The Cross

The proppant transportation is a typical two-phase flow process in a complex cross fracture network during hydraulic fracturing. In this paper, the proppant transportation in cross fractures is investigated by the computational fluid dynamics (CFD) method. The Euler–Euler two-phase flow model and the kinetic theory of granular flow (KTGF) are adopted. The dimensionless controlling parameters are derived by dimensional analysis. The equilibrium proppant height (EPH) and the ratio of the proppant mass (RPM) in the secondary fracture to that in the whole cross fracture network are used to describe the movement and settlement of proppants in the cross fractures. The main features of the proppant transportation in the cross fractures are given, and several relative suggestions are presented for engineering application in the field. The main controlling dimensionless parameters for relative EPH are the proppant Reynolds number and the inlet proppant volume fraction. The dominating dimensionless parameters for RPM are the relative width of the primary and the secondary fracture. Transportation of the proppants with a certain particle size grading into the cross fractures may be a good way for supporting the hydraulic fractures.

scholarly journals Mixing Efficiency Analysis on Droplet Formation Process in Microchannels by Numerical Methods

Processes ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 33 ◽  
Author(s):  
Jin-yuan Qian ◽  
Xiao-juan Li ◽  
Zhi-xin Gao ◽  
Zhi-jiang Jin
Keyword(s):  
Mass Transfer ◽  
Disperse Phase ◽  
Two Phase Flow ◽  
Efficiency Analysis ◽  
Mixing Efficiency ◽  
Phase Flow ◽  
Transfer Enhancement ◽  
Two Phase ◽  
Mass Transfer Enhancement ◽  
The Cross

Liquid–liquid two-phase flow in microchannels has attracted much attention, due to the superiority of mass transfer enhancement. One of the biggest unresolved challenges is the low mixing efficiency at the microscale. Suitable mixing efficiency is important to promote the mass transfer of two-phase flow in microchannels. In this paper, the mixing efficiency in three junction configurations, including a cross-shaped junction, a cross-shaped T-junction, and a T-junction, is investigated by the volume of fluid (VOF) method coupled with user-defined scalar (UDS) model. All three junction configurations are designed with the same hydraulic diameter of 100 μm. Mixing components are distributed in the front and back parts of the droplet. The mixing efficiency in the droplet forming stage and the droplet moving stage are compared quantitatively. Results show that different junction configurations create very different mixing efficiencies, and the cross-shaped T-junction performs best, with relatively lower disperse phase fractions. However, with an increase of the disperse phase fraction, the cross-shaped junction is superior.

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