Notes: Experimental Studies of Disperse Two‐Phase Flow of Molten Polymers Through Dies

1975 ◽  
Vol 19 (3) ◽  
pp. 481-492 ◽  
Author(s):  
B.‐L. Lee ◽  
J. L. White
2005 ◽  
Vol 4 (2) ◽  
Author(s):  
G. Ribatskia ◽  
J. R. Thome

This paper presents a state-of-the-art review of the hydrodynamic aspects of two-phase flow across horizontal tube bundles. The review covers studies related to the evaluation of void fraction, two-phase flow behaviors and pressure drops on the shell side of staggered and in-line tube bundles for upward, downward and side-to-side flows. This study of the literature critically describes the proposed flow pattern maps and semi-empirical correlations for predicting void fraction and frictional pressure drop. These predicting methods are generally based on experimental results for adiabatic air-water flows. A limited number of experimental studies with R-11 and R-113 were also carried out in the past. The review shows noticeable discrepancies among the available prediction methods. Finally, this study suggests that further research focusing on the development of representative databanks and new prediction methods is still necessary.


2007 ◽  
Author(s):  
Longbo Ma ◽  
Hongjian Zhang ◽  
Yuefang Hua ◽  
Hongliang Zhou

2021 ◽  
Vol 895 (1) ◽  
pp. 012002
Author(s):  
V S Alekseev ◽  
R S Seryi

Abstract Currently sluice washing devices are the most common in alluvial gold mining. Their use provides a sufficiently high performance, relatively low power consumption, and acceptable recovery of valuable components. The theoretical provisions of traditional hydraulics make it possible to determine all the main parameters of the movement of particles of rocks and gold in the pulp, however, in real operating conditions of the sluice box, their actual values will differ greatly from the calculated ones, especially if there are solid fractions in the pulp with a particle size of more than 20 mm. This is explained by significant fluctuations in the values of the surface, average and bottom velocities of the two-phase flow, vertical pulsation velocity in conditions of constrained movement of the different fractional composition of rocks. The article presents the results of experimental studies to identify the dependence of the distance traveled by an individual gold particle and host rocks in a two-phase flow through a sluice, the bottom of which is lined with trapping coatings, on the design and technological parameters of the flushing device. The mathematical model for determining this distance formed the basis of the Gold Enriching program. The program allows, in a wide range of initial data, to determine the zones of concentration of gold of a certain size at the sluice boxes.


Author(s):  
Xumao Zou ◽  
Liangxing Li ◽  
Liubo Kong ◽  
Huasheng Wang

Motivated by reducing the uncertainties in coolability analysis of a debris bed, this paper proposed a modified model for the pressure drops of two phase flow through packed beds with coarse particles based on the experimental studies. The experiments are carried out on the test facility of DEBECO-LT (DEbris BEd COolability-Low Temperature), which was designed to investigate single / two-phase flow in porous beds. The coarse particles are packed in the cylindrical test section with the inner diameter of 120 mm and the height of 600 mm. Through single-phase flow tests in homogeneous beds, the reliability of the whole experimental system is ensured. Then two-phase flow tests are performed to investigate the flow characteristics, to provide basic data for verifying and modifying the existing models. The results show that, the interfacial drag in beds with coarse particles will result in a decreasing tendency in the pressure drop curves along with the fluid velocity, and the the effect of interfacial drag should be considered in the debris coolability analysis models for beds with coarse particles. Compared with the existing models, the new model shows relatively satisfactory forecasting ability, and the predictions have favorable agreement with existing experimental data under various conditions. This modified model could be applied to calculate the pressure drops of two-phase flow in coarse-particle beds.


1973 ◽  
Vol 17 (4) ◽  
pp. 1203-1225 ◽  
Author(s):  
Thomas C. Yu ◽  
Chang Dae Han

Author(s):  
Rufat Sh. Abiev ◽  
◽  
Ritunesh Kumar ◽  

In addition to the previously created hydrodynamics model, a mathematical model describing the heat transfer parameters of two-phase flow is constructed. Particular role of longitudinal convection in the heat transport is shown. The experimental studies confirmed a microchannel heat pipe operability with a two-phase flow in a circulating mode. A circulating two-phase Taylor flow in microchannel was considered to be more efficient for overall heat transfer in a heat pipe compared to the pulsating (oscillating) heat pipe. The advantages of circulating two-phase Taylor flow related to the pulsating heat pipes are discussed on the proposed mathematical model basis. The conditions of experimental proof of the proposed mathematical model were elaborated.


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