Interaction Between Two Falling Droplets in the Liquid-Liquid Two Phase Flow

Author(s):  
Nao Ninomiya ◽  
Takeshi Mori

Although the phenomena related to the multiphase flow can be found in many kinds of industrial and engineering applications, the physical mechanism of the multiphase flow has not been investigated in detail. The major reason for the lack of data in the multiphase flow lies in the difficulties in measuring the flow quantities of the multiple phases simultaneously. The difference in the refractive indices makes the visualization in the vicinity of the boundary of the multiple phases almost impossible. In this study, the refractive index of the aqueous phase has been equalized to that of the oil phase by adjusting the concentration of aqueous solution. Presently, the simultaneous visualization and the PIV measurement have been carried out about the both phases of the liquid-liquid two-phase flow. The measurement has been carried out for the flow field around and inside of two falling droplets interacting each other while they travel.

2019 ◽  
Vol 53 (5) ◽  
pp. 1763-1795 ◽  
Author(s):  
Khaled Saleh

This article is the first of two in which we develop a relaxation finite volume scheme for the convective part of the multiphase flow models introduced in the series of papers (Hérard, C.R. Math. 354 (2016) 954–959; Hérard, Math. Comput. Modell. 45 (2007) 732–755; Boukili and Hérard, ESAIM: M2AN 53 (2019) 1031–1059). In the present article we focus on barotropic flows where in each phase the pressure is a given function of the density. The case of general equations of state will be the purpose of the second article. We show how it is possible to extend the relaxation scheme designed in Coquel et al. (ESAIM: M2AN 48 (2013) 165–206) for the barotropic Baer–Nunziato two phase flow model to the multiphase flow model with N – where N is arbitrarily large – phases. The obtained scheme inherits the main properties of the relaxation scheme designed for the Baer–Nunziato two phase flow model. It applies to general barotropic equations of state. It is able to cope with arbitrarily small values of the statistical phase fractions. The approximated phase fractions and phase densities are proven to remain positive and a fully discrete energy inequality is also proven under a classical CFL condition. For N = 3, the relaxation scheme is compared with Rusanov’s scheme, which is the only numerical scheme presently available for the three phase flow model (see Boukili and Hérard, ESAIM: M2AN 53 (2019) 1031–1059). For the same level of refinement, the relaxation scheme is shown to be much more accurate than Rusanov’s scheme, and for a given level of approximation error, the relaxation scheme is shown to perform much better in terms of computational cost than Rusanov’s scheme. Moreover, contrary to Rusanov’s scheme which develops strong oscillations when approximating vanishing phase solutions, the numerical results show that the relaxation scheme remains stable in such regimes.


2011 ◽  
Vol 189-193 ◽  
pp. 2181-2184
Author(s):  
Heng Zhang ◽  
Xiao Ming Qian ◽  
Zhi Min Lu ◽  
Yuan Bai

The functions of hydroentangled nonwovens are determined by the degree of the fiber entanglement, which depend mainly on parameters of the water jet. According to the spun lacing technology, this paper set up the numerical model based on the simplified water jetting model, establishing the governing equations, and the blended two-phase flow as the multiphase flow model. This paper simulation the water needle after the water jetting from the water needle plate in the different pressure (100bar, 60bar, 45bar, 35bar).


Author(s):  
Xianfa Li ◽  
Shuoping Zhong ◽  
Yanfei Sun

It is an important achievement of modern techniques to determine the mass flow rate and the phase fraction of wet steam by measuring the orifice plate differential pressure noise. The orifice plate differential pressure noise of air-water two-phase flow in horizontal and vertical rising pipelines were analyzed. Kinds of calculation methods were tried to get the differential pressure noise. From the difference waveform of the differential pressure square root that the acquisition card got and the mean square root of the sample that got before, the first in first out (FIFO) principle was used to get the differential pressure noise. Result shows that the differential pressure noise has different level at different vapor flow rate with the same water flow rate, conclusions show that the two-parameter measurement by using orifice plate differential pressure noise may be possibly used in vertical rising gas-water two phase flow.


Author(s):  
Steven P. O’Halloran ◽  
B. Terry Beck ◽  
Mohammad H. Hosni ◽  
Steven J. Eckels

Particle image velocimetry (PIV) is a well established measurement technique to measure velocity in a variety of different fluids. Using PIV to measure single-phase flow is well established, but recently PIV has been used to measure two-phase flows as well. Most two-phase PIV measurements have been for dispersed or bubbly flows, often utilizing the bubbles or droplets as PIV seed particles. However, there are other types of two-phase flow situations, such as stratified or slug flow, in which PIV measurement techniques are not yet well established. Situations such as these require both liquid and gas phases to be seeded separately with particles that can distinguish each phase. A particle injection method is presented for the air phase of a two-phase system using fluorescent tracer particles. Information about the system, including details of the fluorescent particles and injection device are given. The device injects micron sized fluorescent particles at a uniform rate into the flow of interest. A cut-off lens filter on the PIV camera is used to distinguish the fluorescent particles used for the air phase from non-fluorescent particles used in the liquid phase. Results using the technique with a two-phase air/water system in a thin rectangular channel for stratified/wavy flow are given. The channel is enclosed in a clear acrylic plastic tank and the dimensions of the channel are 600 mm long, 40 mm high, and 15 mm wide. The results demonstrate the ability to use PIV to measure the gas phase of a two-phase system for stratified/wavy flow and the method could be extended to other two-phase flow regimes as well.


1999 ◽  
Vol 19 (4) ◽  
pp. 194-203 ◽  
Author(s):  
Kaoru Miyazaki ◽  
Gang Chen ◽  
Fujio Yamamoto ◽  
Jun-ichi Ohta ◽  
Yuichi Murai ◽  
...  

2020 ◽  
Vol 90 (4) ◽  
pp. 560
Author(s):  
Н.Н. Симаков

A numerical model and the results of calculation of the interfacial mass transfer in a two-phase flow formed by spraying a liquid in a gas with a nozzle are described. The basis of the proposed mathematical model is the differential equations of the nonstationary flow of a compressible medium supplemented by the equation of mass transfer from a gas to droplets. Going over to the difference analogues of the equations of continuity and phase motion, we used the well-known explicit Lax-Vendroff scheme. Herein, the axial profiles of the velocities of droplets and gas, concentrations of gas impurity in a free spray flow, as well as radial profiles of impurity concentrations in a two-phase flow through a cylindrical apparatus are calculated and presented accounting the early drag crisis of droplets, the mass-transfer crisis and the turbulent friction characteristics in gas discovered in previous experiments. Calculations show dependences of the volumetric gas flow, concentration of the gas admixture at the apparatus output, and the amount of impurity absorbed by a liquid on the height and cross-section area of the apparatus.


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