scholarly journals Loss coefficients of ice slurry in sudden pipe contractions

2010 ◽  
Vol 31 (3) ◽  
pp. 73-86
Author(s):  
Łukasz Mika
Keyword(s):  
Mass Fraction ◽  
Flow Resistance ◽  
Volume Fraction ◽  
Experimental Studies ◽  
Solid Particles ◽  
Minimal Flow ◽  
Ice Slurry ◽  
Slurry Flow ◽  
Flow Through ◽  
Loss Coefficients

Loss coefficients of ice slurry in sudden pipe contractionsIn this paper, flow systems which are commonly used in fittings elements such as contractions in ice slurry pipelines, are experimentally investigated. In the study reported in this paper, the consideration was given to the specific features of the ice slurry flow in which the flow behaviour depends mainly on the volume fraction of solid particles. The results of the experimental studies on the flow resistance, presented herein, enabled to determine the loss coefficient during the ice slurry flow through the sudden pipe contraction. The mass fraction of solid particles in the slurry ranged from 5 to 30%. The experimental studies were conducted on a few variants of the most common contractions of copper pipes: 28/22 mm, 28/18 mm, 28/15 mm, 22/18 mm, 22/15 mm and 18/15 mm. The recommended (with respect to minimal flow resistance) range of the Reynolds number (Re about 3000-4000) for the ice slurry flow through sudden contractions was presented in this paper.

scholarly journals Ice slurry flow and heat transfer during flow through tubes of rectangular and slit cross-sections

2014 ◽  
Vol 35 (3) ◽  
pp. 171-190
Author(s):  
Beata Niezgoda-Żelasko ◽  
Jerzy Żelasko
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Cross Sections ◽  
Heat Transfer Process ◽  
Solid Particles ◽  
Ice Slurry ◽  
Slurry Flow ◽  
Transfer Coefficients ◽  
Laminar And Turbulent Flow ◽  
Flow Through

Abstract The paper presents the results of experimental research of pressure drop and heat transfer coefficients of ice slurry during its flow through tubes of rectangular and slit cross-sections. Moreover, the work discusses the influence of solid particles, type of motion and cross-section on the changes in the pressure drop and heat transfer coefficient. The analysis presented in the paper allows for identification of the criterial relations used to calculate the Fanning factor and the Nusselt number for laminar and turbulent flow, taking into account elements such as phase change, which accompanies the heat transfer process. Ice slurry flow is treated as a generalized flow of a non-Newtonian fluid.

scholarly journals Numerical Investigation of the Pressure Drop Characteristics of Isothermal Ice Slurry Flow under Variable Ice Particle Diameter

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Shehnaz Akhtar ◽  
Taqi Ahmad Cheema ◽  
Haider Ali ◽  
Moon Kyu Kwak ◽  
Cheol Woo Park
Keyword(s):  
Pressure Drop ◽  
Flow Velocity ◽  
Mass Fraction ◽  
Fluid Dynamic ◽  
Particle Diameter ◽  
Ice Slurry ◽  
Slurry Flow ◽  
Two Phase ◽  
Wide Range ◽  
Volumetric Loading

Ice slurry is an advanced secondary refrigerant that has been attracting considerable attention for the past decade due to the growing concerns regarding energy shortage and environmental protection. To stimulate the potential applications of ice slurry, the corresponding pressure drop of this refrigerant must be comprehensively investigated. The flow of ice slurry is a complex phenomenon that is affected by various parameters, including flow velocity, ice particle size, and ice mass fraction. To predict the pressure drop of ice slurry flow in pipes, a mixture computational fluid dynamic model was adopted to simulate a two-phase flow without considering ice melting. The numerical calculations were performed on a wide range of six ice particle sizes (0.1, 0.3, 0.5, 0.75, 1, and 1.2 mm) and ice mass fraction ranging within 5%–20% in the laminar range of ice slurry flow. The numerical model was validated using experimental data. Results showed that the ice volumetric loading and flow velocity have a direct effect on pressure drop; it increases with the increase in volumetric concentration and flow velocity. The findings also confirmed that for constant ice mass fraction and flow velocity, the pressure drop is directly and inversely related to the particle and pipe diameters, respectively. Moreover, the rise in pressure drop is more significant for large ice particle diameter in comparison to smaller size ice particles at high values of ice concentration and flow velocity.

scholarly journals Modeling of Ice Slurry Flow through Bend Pipe

2020 ◽  
Vol 802 ◽  
pp. 012001
Author(s):  
K.S. Rawat ◽  
A. Verma ◽  
A. Uniyal ◽  
H.P. Gangwar ◽  
A.K. Pratihar
Keyword(s):  
Ice Slurry ◽  
Slurry Flow ◽  
Bend Pipe ◽  
Flow Through

Pressure Drop in Slurry Pipe With Stationary Deposit

2007 ◽  
Author(s):  
Va´clav Matousˇek
Keyword(s):  
Pressure Drop ◽  
Particle Dispersion ◽  
Solid Particles ◽  
Slurry Flow ◽  
Frictional Pressure Drop ◽  
Pipe Flows ◽  
Proposed Model ◽  
Slurry Flows ◽  
Flow Through ◽  
Different Dimensions

Majority of slurry pipelines operates at flow velocities high enough to maintain all transported solid particles in motion. Nevertheless, it happens sometimes that pipeline operations with stationary deposits of solids at the bottom of a pipe are found in practice (e.g. sand transportation through long pipelines connected with a dredge). Many different models are available for a prediction of the pressure drop in a slurry pipe without a deposit. Very little is known about flows with stationary deposits. The paper discusses pipe flows of sand-water slurries at velocities lower than the deposition-limit velocity. Results of laboratory tests of slurry flows with granular beds at the bottom of a slurry pipe are analyzed with an aim to establish a predictive model for the frictional pressure drop associated with this type of slurry flow. The pressure-drop model is based on a description of prevailing mechanisms that are identified to govern solids dispersion and solids friction in slurry flows at different conditions (e.g. different average concentrations of solids above the stationary bed, different dimensions of the discharge area above the bed etc.). The proposed model is composed of continuity, momentum, boundary-friction and particle-dispersion equations. The empirical stratification-ratio equation relates the effect of particle dispersion within the slurry flow with the flow friction at the top of the stationary deposit. This friction is recognized as a major contributor to the total pressure drop in the slurry flow through a pipe with a stationary deposit.

scholarly journals Entropy Generation of Forced Convection during Melting of Ice Slurry

Entropy ◽  
2019 ◽  
Vol 21 (5) ◽  
pp. 514
Author(s):  
Beata Niezgoda-Żelasko
Keyword(s):  
Heat Exchange ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Minimum Entropy ◽  
Ice Slurry ◽  
Slurry Flow ◽  
Exchange Processes ◽  
Minimum Entropy Generation

This paper looks at entropy generation during ice slurry flow in straight pipes and typical heat exchanger structures used in refrigeration and air-conditioning technology. A dimensionless relationship was proposed to determine the interdependency between flow velocity and the volume fraction of ice, for which the entropy generation rates were at the minimum level in the case of non-adiabatic ice slurry flow. For pipe flow, the correlation between the minimum entropy generation rate and the overall enhancement efficiency was analyzed. As regards heat exchange processes in heat exchangers, the authors analyzed the relationship between the minimum entropy generation rate and the heat exchange surface area and exchanger efficiency.

Study of pumping effect in flow-through electrolysers

1983 ◽  
Vol 48 (8) ◽  
pp. 2232-2248 ◽  
Author(s):  
Ivo Roušar ◽  
Michal Provazník ◽  
Pavel Stuhl
Keyword(s):  
Natural Convection ◽  
Balance Equation ◽  
Volume Fraction ◽  
Industrial Applications ◽  
Pumping Effect ◽  
Flow Through ◽  
The Mean ◽  
The Difference

In electrolysers with recirculation, where a gas is evolved, the pumping of electrolyte from a lower to a higher level can be effected by natural convection due to the difference between the densities of the inlet electrolyte and the gaseous emulsion at the outlet. An accurate balance equation for calculation of the rate of flow of the pumped liquid is derived. An equation for the calculation of the mean volume fraction of bubbles in the space between the electrodes is proposed and verified experimentally on a pilot electrolyser. Two examples of industrial applications are presented.

Study on Cavity Growth in Uniaxial Tension of ZK60 Magnesium Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 687-690
Author(s):  
Yan Dong Yu ◽  
De Liang Yin ◽  
Bao You Zhang
Keyword(s):  
Volume Fraction ◽  
Cavity Growth ◽  
Experimental Studies ◽  
Superplastic Forming ◽  
Cavity Radius ◽  
Analysis Software ◽  
Mixed Characteristic ◽  
Substantial Growth ◽  
Zk60 Magnesium Alloy ◽  
Electronic Microscope

Cavity growth is a typical microstructure feature in superplastic forming (SPF) of materials. Substantial growth and interlink of cavities in superplastic deformation usually lead to reduction in elongation, even to failure. Consequently, it is necessary to investigate the mechanism and model of cavity growth. In this paper, experimental studies on cavity growth were carried out by means of superplastic tension of ZK60 magnesium alloys. Scanning electronic microscope (SEM) was employed for observation of fractography. Experimental cavity radius and volume fraction were determined by optical microscopy and corresponding picture-based analysis software. It is found that, the fractured surfaces after a superplastic elongation have a mixed characteristic of intergranular cavities and dimples. Further, the cavity growth is identified to follow a exponentially increasing mode.

Sign in / Sign up

Export Citation Format

Share Document