Liquid Plug Research Articles

On The Existence, Formation and Stabilisation Of Lyne Vortices In Helically Coiled Reactors At Moderate Reynolds Numbers

The occurrence of Dean and Lyne vortices in curved and coiled tubes is widely known. This paper is on the tracks of vortex structures in more resent helically coiled reactors, namely the Coiled-Flow-Reverser (CFR) and the Coiled-Flow-Inverter (CFI) (see top of figure 1). Time-resolved laser induced fluorescence (LIF) and time-resolved particle image velocimetry (TR-PIV) are used to characterize the existence of Lyne vortices in a range of Reynolds numbers from 500 to 2400 for single phase liquid-liquid mixing flows (see centre of figure 1). In this study parameters like the Reynolds number, the inlet angle and the geometry of the helically coiled reactor are varied and their influence on the vortex occurrence and the mixing coefficient is shown. The results are then compared to two-phase flow structures in helical pipes from Müller et al. (2021), in which secondary and tertiary vortices inside the liquid plugs exist as well. Two transition points for the formation of Lyne vortices in the CFI could be characterised. While Lyne instabilities occur in straight horizontal helix geometries at Reynolds numbers above 1000, in the CFI the first Lyne vortices formed at a Reynolds number of 560. From a Reynolds number of 1600 onwards, these begin to break off, whereby the Lyne vortices continue to occur continuously but no longer steadily. Pseudo-3D reconstructions of the flow in the CF and the CFI are used to show the flow behaviour and the occurrence of Lyne instabilities for different conditions.

Surface-tension-driven evolution of a viscoplastic liquid coating the interior of a cylindrical tube

One mechanism for airway closure in the lung is the surface-tension-driven instability of the mucus layer which lines the airway wall. We study the instability of an axisymmetric layer of viscoplastic Bingham liquid coating the interior of a rigid tube, which is a simple model for an airway that takes into account the yield stress of mucus. An evolution equation for the thickness of the liquid layer is derived using long-wave theory, from which we also derive a simpler thin-film evolution equation. In the thin-film case we show that two branches of marginally yielded static solutions of the evolution equation can be used to both predict the size of the initial perturbation required to trigger instability and quantify how increasing the capillary Bingham number (a parameter measuring yield stress relative to surface tension) reduces the final deformation of the layer. Using numerical solutions of the long-wave evolution equation, we quantify how the critical layer thickness required to form a liquid plug in the tube increases as the capillary Bingham number is increased. We discuss the significance of these findings for modelling airway closure in obstructive conditions such as cystic fibrosis, where the mucus layer is often thicker and has a higher yield stress.

Embolization for Type Ia Endoleak after EVAR for Abdominal Aortic Aneurysms: A Systematic Review of the Literature.

(1) Successful endovascular repair for abdominal aortic aneurysms is based on the complete exclusion of the aneurysm sac from the systemic circulation. Type Ia endoleak (ELIA) is defined as the persistent perfusion of the aneurysm sac due to incomplete proximal sealing between aorta and endograft, with a consequent risk of rupture and death. Endoleak embolization has been sporadically reported as a viable treatment for ELIA. (2) A systematic literature search in PubMed of all publications in English about ELIA embolization was performed until February 2022. Research methods and reporting were performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Data regarding patient numbers, technical success (endoleak absence at control angiography), reinterventions, clinical and imaging follow-up, and outcomes were collected and examined by two independent authors. (3) Twenty-one papers (12 original articles, 9 case reports) reported on 126 patients (age range 58–96 years) undergoing ELIA embolization 0–139 months after the index procedure. Indication for embolization was most often founded on unfavorable anatomy and patient comorbidities. Embolic agents used include liquid embolic agents, coils, plugs and combinations thereof. Technical success in this highly selected cohort ranged from 67–100%; the postprocedural complication rate within 30 days was 0–24%. ELIA recurrence was reported as 0–42.8%, with a secondary ELIA-embolization-intervention success rate of 50–100%. At a follow-up at 0–68 months, freedom from sac enlargement amounted to 76–100%, freedom from ELIA to 66.7–100%. (4) Specific literature about ELIA embolization is scant. ELIA embolization is a valuable bailout strategy for no-option patients; the immediate technical success rate is high and midterm and long-term outcomes are acceptable.

An On-Chip Liquid Metal Plug Generator.

Gallium-based liquid metal nonspherical droplets (plugs) have seen increasing demand recently mainly because their high aspect ratios make them beneficial for a wide range of applications, including microelectromechanical systems (MEMS), microfluidics, sensor technology, radio-frequency devices, actuators, and switches. However, reproducibility of the generation of such plugs, as well as precise control over their size, is yet challenging. In this work, a simple on-chip liquid metal plug generator using a commercially available 3D microprinter is presented and the plug generator in poly(dimethylsiloxane) is replicated via soft lithography. Liquid metal plugs are generated via a combination of electrochemical oxidation, design of well-defined constrictions based on Laplace pressure, and the application of modulated voltage control signals. It is shown that plugs of various aspect ratios can be generated reproducibly for channel widths of 0.5, 0.8, and 1.5mm with constriction widths of 0.1mm at 6V. Laplace-pressure-controlled plugs in constricted channels are compared to modulated-voltage-generated plugs in straight channels showing that this technique provides significantly enhanced reproducibility and control over the size and spacing between the plugs. This work paves the way to sub-millimeter liquid metal plugs generated directly on-chip for on-demand MEMS and microfluidic applications.

Design of a cryogenic two-phase flow visualization system for cryogenic pulsating heat pipe

A cryogenic pulsating heat pipe (PHP), as a novel two-phase heat transfer device, has been studied for cooling superconducting magnets because of its high transfer coefficient, simple configuration, and flexible arrangement. From the results of the room temperature PHP experiments, it was noticed that the flow characteristics and the flow pattern of the PHP are complex, which affect the heat transfer performance of the PHP. In this work, a cryogenic two-phase flow visualization system for cryogenic PHP by using a GM cryocooler is developed to get a better understanding of the oscillating behavior, the distribution of vapor slug and liquid plug, and the flow pattern of the cryogenic working fluid. The details of the design of this system are presented. The performance of the GM cryocooler is verified and the temperature distribution of the cooling system is discussed. The liquid slugs and vapor bubbles were observed during the cool-down period. The visualization experiment will be carried out with the cryogenic PHP prototype installed and operated in a vertical position using nitrogen as a working fluid.

Experimental characterization of the thermodynamic cycle of a self-oscillating fluidic heat engine (SOFHE) for thermal energy harvesting

We experimentally studied the thermodynamic cycle of a single branch pulsating heat pipe (SB-PHP) to show its potential as a Self-Oscillating Fluidic Heat Engine (SOFHE) capable of generating electric power from heat. The engine consists of a vapor bubble trapped by an oscillating liquid plug acting like a piston in a tube of mm-scale diameter. Pressure build-up in the vapor bubble can provide net mechanical work that can then be converted into electrical energy by coupling the liquid plug motion to an electro-mechanical transducer. The transducer can be represented, in a first approach, as a dissipative mechanical load acting on the engine that will tend to reduce the oscillations. Unlike a standard pulsating heat pipe, we aim here at maximizing the mechanical work produced rather than the heat transfer rate. However, it is still unclear how the unique thermodynamic cycle of the oscillating vapor bubble-liquid plug behaves under a mechanical load and what effects the design parameters have on the generated mechanical power. Thereby, we conducted experiments to measure the pressure, displacement and operating frequency from which the generated mechanical work and power can be evaluated under varying loads. We observed a maximum mechanical power density with a magnitude of 0.5 mW/cm3 at an optimal load and a cycle efficiency ratio with respect to Carnot of 30%. We also studied the effect of the heat source operating temperature and two design parameters on the mechanical power density. It was shown that the mechanical power density can be improved by increasing the heat source temperature, adding wicking structures inside the tube as well as decreasing the liquid length. Finally, we found that the mechanical power density of the SOFHE makes it a promising technology to power a wide range of low-power wireless sensors (requiring 10′s of microwatts) for the Internet of Things (IoT), if designed with adequate electro-mechanical coupling.

Specific features of the multiphase fluid subsea pipeline operation at the liquid accumulation mode

The operation modes of an extensional subsea pipeline of multiphase fluid at the initial stage of the offshore gas condensate field development under the conditions of liquid accumulation are studied. By means of the dynamic simulation of the slug flow mode, the frequency and volume of liquid plugs removed from the pipeline are analyzed as a function of the gas flow rate. It is demonstrated that with a decrease of the gas flow rate, the steadystate hydraulic calculations predict significantly lower values of the liquid volume flow rate at the pipeline outlet compared to the results of the dynamic simulation. The dynamics of the liquid removal from the pipeline with an increase of the gas flow rate is studied. It is shown that the surge liquid volume increases sharply at a rapid growth of the gas flow rate, which leads to restrictions on the increase in the well flow rate. Keywords: subsea pipeline; natural gas; multiphase fluid; liquid accumulation; slug flow.

Experimental Study on Gas–Liquid Interface Evolution during Liquid Displaced by Gas of Mobile Pipeline

The mobile pipeline is the most effective and reliable means for the emergency oil transfer task, which is temporarily laid on the field. After completing the task, the oil in the pipeline should be emptied before the mobile pipeline is removed. The oil in pipeline gradually displaced by the air is a main method of pipeline evacuation, which is the only choice of jet fuel pipeline. Due to the convection between gas and oil phases, the length of the oil–gas mixing section and the evolution of the oil–gas interface change with time. The evolution of the gas–liquid interface directly determines the different flow patterns of oil–gas two phases, which are very important for the mobile pipeline evacuation. In this paper, the characteristics of the gas–liquid interface evolution during the water displaced by air are studied, using the multi-phase pipeline experiment. Through the change of the gas–liquid interface in the initial stage of gas cap evacuation, it is found that the gas–liquid interface can be divided into smooth, wavy, and dispersed forms under different initial gas flow rates and different inclination angles. Slug phenomenon may occur in the process of gas-carrying liquid flow in the pipeline. The emergence of slug is mainly affected by hydraulic conditions and pipeline operating conditions. The liquid plug body is complex and unstable, and there will be a mutual transition between different liquid slug shapes. The increase of the inclination angle and gas phase velocity will accelerate the occurrence of liquid slug frequency.

自由界面渦による気相巻き込み現象の定量評価

On the gas-liquid interface of a sodium-cooled fast reactor, gas (bubble) entrainment can be caused by free surface vortices, which may result in, e.g. disturbance in core power. Therefore, it is important to develop an evaluation model to predict accurately the entrained gas flow rate for the prevention of such undesirable phenomena. In the previous studies, simple gas entrainment experiments have been conducted, in which, typically, the gas entrainment is caused by free surface vortex in an upper-tank and the entrained gas is separated from liquid in a lower-tank which is connected with the upper-tank by a suction pipe. The entrained gas flow rate had been measured while the liquid flow parameters, e.g. liquid level or flow rate, are changed. However, the influence of the pressure difference between the upper and lower tanks had not been focused on those studies. In this study, to measure accurate the entrained gas flow rate, a simple gas entrainment experiment is conducted with focusing on the effect of the pressure difference between upper and lower tanks. The pressure difference between upper and lower tanks are controlled by changing the gas pressure in the lower-tank. As a result, it is confirmed that the entrained gas flow rate increases with increasing the pressure difference between upper and lower tanks. By the visualization of the two-phase flow in the suction pipe, it is also observed that the pressure drop in the suction pipe increases with the increase in the entrained gas flow rate when intermittent liquid plug is generated in the two-phase flow.

Analysis of processes in magnetorheological sealer considering for magnetic fluid deformation

The small size of the working gap in the sealer makes many physical measurements difficult or impossible. The main way to study the processes inside the device is to use analytical and numerical mathematical modeling. Most researchers apply finite-element calculation of magnetic field and analytically find the difference in pressure. Currently, there are few studies devoted to multiphysics numerical calculations of the processes in magnetorheological seal. The use of numerical models allows considering the dependence of rheological properties of magnetic fluid on hydrodynamic, temperature and magnetic fields, the real geometry of the working zone. Compared to the analytical models, a numerical one includes a smaller number of assumptions and allows visualizing various flow parameters, which are especially important for the analysis. The purpose of this study is to analyze the effect of the deformation of the magnetorheological plug in case of pressure difference held by the sealer. The study is based on the developed numerical model with the related calculation of magnetic and hydrodynamic fields. The study is carried out based on the theories of ferrohydrodynamics, hydrodynamics and electromagnetic field. Integrated finite-element modeling of the magnetic and hydrodynamic fields of the magnetorheological sealer in Comsol Мultiphysics has been used. A numerical model of the magnetorheological sealer characterized by automatic rearrangement of the boundaries of the liquid plug based on the balance of pressures inside the liquid has been developed. The distribution results of magnetic induction and pressure in the working gap of the sealer, considering changes in the boundaries of the magnetic fluid, has been obtained. Comparison of the results of the obtained retained pressure drop and the results of other models has been carried out. A numerical mathematical model that considers the deformation of the magnetorheological plug has been developed. The model makes it possible to estimate the influence of centrifugal forces of the rotating shaft on the retained pressure drop. The results can be used to create high-speed seal components. The difference of the value of analytical calculation does not exceed 5 %. The assumption about full filling of the working gap with magnetic fluid 2,5 times underestimates the retained pressure difference at high shaft rotation speeds.

A review on the heat transfer performance of pulsating heat pipes

ABSTRACT The miniaturisation of systems has widely attracted researchers to contribute to the thermal performance enhancement utilising efficient heat transfer devices. Pulsating heat pipe (PHP) is an inimitable passive two-phase energy conversion/transport device capable of transferring extensive heat energy by oscillating liquid slugs and vapour plugs from hot to cold areas suitable for the management of generation of heat in electronics. Several theoretical, experimental and visualisation studies are made on PHP to understand operational mechanisms and to arrive at optimal conditions. Although PHP has potential application in the field of heat management, its effective utilisation is limited due to complex operational mechanisms.It is observed that PHPs are effective and reliable devices for utilisation in numerous energy systems. It is observed that PHPs are effective and reliable devices for utilisation in numerous energy systems. Advanced research is directed towards numerical simulations on the evaluation of PHP performance with non-conventional working fluids. It is found that the use of ternary hybrid nanofluid in PHP has scope for research work. The objective of this paper is to review the existing methodologies for enhancing the PHP overall performance and its applications.

Back Cover: Single bubble in‐tube microextraction coupled with capillary electrophoresis

DOI: 10.1002/elps.202100216 The cover picture shows three modes of headspace liquid phase microextraction (HS-LPME) in-line coupled with CE. Headspace single drop microextraction (HS-SDME)-CE: When a single drop of the acceptor phase (blue) is formed at the inlet of a separation capillary filled with a run buffer (pale pink), the analytes evaporated from the sample donor solution (green) into the HS are extracted into the drop leaving less- or non-volatile matrix components in the sample. After extraction, a portion of the drop containing enriched analytes is injected into the capillary for CE analysis. Due to the large volume ratio between the sample donor solution and the acceptor drop, and the large surface-to-volume ratio of the drop, the sample enrichment factors obtained with SDME are quite high for a given extraction time, compared with other conventional LPME techniques. However, it is critical to maintain the drop stably attached to the capillary during extraction and thus it is rather difficult to carry out SDME for a long time especially under harsh conditions such as elevated temperature. Headspace in-tube microextraction (HS-ITME)-CE: Using a liquid plug in the capillary inlet as an acceptor phase instead of a hanging drop, the shortcomings of the hanging drop can be resolved. In HS-ITME-CE, the capillary inlet containing the acceptor plug is simply placed in the HS above a sample solution. Since the acceptor phase is well protected by the capillary, a long extraction at a temperature as high as 90°C can be performed with ease. Furthermore, since the enriched acceptor plug is already inside the capillary, the whole extract can be utilized for the subsequent CE analysis without additional injection step. Single bubble in-tube microextraction (SB-ITME)-CE: For a short extraction time, the extraction efficiency of HS-SDME or HS-ITME was not maximized because it takes some time for the analytes to fill the HS and reach saturated concentrations, especially for compounds of low volatility. By using a single bubble as a micro-HS formed at the inlet of a separation capillary immersed in the sample donor solution, the HS extraction can be expedited without waiting for the HS equilibration. Since the surface-to-volume ratio of the submicroliter bubble is much higher than that of a conventional HS of a few milliliters or more, the analyte concentrations in the bubble can be replenished much more rapidly for short extraction times. SB-ITME demonstrated higher sample enrichments than HS-ITME for a short HS extraction of chlorophenols in water.

Propagation and rupture of elastoviscoplastic liquid plugs in airway reopening model

The propagation and rupture of mucus plugs in human lungs is investigated experimentally by injecting synthetic mucus in a pre-wetted capillary tube. The rheology of our test liquid is thoroughly characterized, and four samples of synthetic mucus are considered in order to reproduce elastoviscoplastic regimes of physiological interest for airway reopening. Our experiments demonstrate the significant impact of the viscoplasticity and viscoelasticity of mucus. In support to our experiments, we propose a one-dimensional reduced-order model that takes into account capillarity, and elastoviscoplasticity. Our model manages to capture the cross-section averaged dynamics of the liquid plug and is used to elucidate and interpret the experimental evidence. Relying on it, we show that the liquid film thickening due to non-Newtonian effects favors plug rupture, whereas the increase of the effective viscosity due to higher yield stresses hinders plug rupture. As a result of such two effects, increasing the polymeric concentration in the mucus phase leads to a net increase of the rupture time and traveling length. Hence, non-Newtonian effects hinder airway reopening.

Scaled-up droplet generation in parallelised 3D flow focusing junctions

Monodispersed organic phase droplets with an average diameter from 20 to 200 µm were produced at the rate of up to 20,000 droplets per second in a glass microfluidic chip composed of 7 parallel 3D flow focusing junctions with 100 µm-deep channels. The continuous phase was 2 wt% polyvinyl alcohol solution, while the dispersed phase was dichloromethane, n-dodecane, and polydimethylsiloxane 10 cSt fluid corresponding to the dispersed-to-continuous-phase viscosity ratio of 0.2, 0.8 and 6.1, respectively. Four different droplet generation regimes were observed, dripping, squeezing, jetting, and threading. The regions where each of these regimes was stable were mapped using Weber number of the dispersed phase and capillary number of the continuous phase. The transitions between the droplet formation regimes were governed by the Weber number of the dispersed phase, indicating that inertial forces in the dispersed phase were more relevant than viscous forces in controlling the transition. Stable droplet generation in dripping regime in each junction was maintained for at least 6 h. The coefficient of variation of droplet sizes from individual junctions and all junctions combined was < 3% under optimal conditions. The droplet size variations between different junctions were greater than those within each junction. Liquid plugs were produced in the squeezing regime at the dispersed-to-continuous phase flow rate ratio greater than one. This study is the first investigation of droplet generation in multiple 3D flow-focusing junctions with potential applications for the production of drug microcarriers using emulsification solvent evaporation, especially for the encapsulation and controlled delivery of lipophilic drugs.

Numerical simulation of pulmonary airway reopening by the multiphase lattice Boltzmann method

Not only coughing and sneezing, but even normal breathing can produce aerosols, because rupture of liquid plugs forms microdroplets during pulmonary airway reopening. Aerosols are important carriers of various viruses, such as influenza, SARS, MERS, and COVID-19. To control airborne disease transmission, it is important to understand aerosol formation, which is related to the pressure drop, liquid plug, and film. In addition, the detrimental pressure and shear stress at the airway wall produced in the process of airway reopening have also attracted a lot of attention. In this paper, we proposed a multiphase lattice Boltzmann method to numerically simulate pulmonary airway reopening, in which the gas-liquid transition is directly driven by the equation of state. After validating the numerical model, two rupture cases with and without aerosol formation were compared and analyzed. We found that injury of the epithelium in the case with aerosol formation was almost the same as that without aerosol formation, even though the pressure drop in the airway increased by about 50%. Further investigation showed that the aerosol size and maximum differences of the wall pressure and shear stress increased with pressure drop in the pulmonary airway. A similar trend was observed when the thickness of the liquid plug became larger, while an opposite trend occurred when the thickness of the liquid film increased. The model can be extended to study generation and transmission of bioaerosols carrying the influenza or coronavirus.

Experimental analysis and transient numerical simulation of a large diameter pulsating heat pipe in microgravity conditions

A multi-parametric transient numerical simulation of the start-up of a large diameter Pulsating Heat Pipe (PHP) specially designed for future experiments on the International Space Station (ISS) are compared to the results obtained during a parabolic flight campaign supported by the European Space Agency. Since the channel diameter is larger than the capillary limit in normal gravity, such a device behaves as a loop thermosyphon on ground and as a PHP in weightless conditions; therefore, the microgravity environment is mandatory for pulsating mode. Because of a short duration of microgravity during a parabolic flight, the data concerns only the transient start-up behavior of the device. One of the most comprehensive models in the literature, namely the in-house 1-D transient code CASCO (French acronym for Code Avancé de Simulation du Caloduc Oscillant: Advanced PHP Simulation Code in English), has been configured in terms of geometry, topology, material properties and thermal boundary conditions to model the experimental device. The comparison between numerical and experimental results is performed simultaneously on the temporal evolution of multiple parameters: tube wall temperature, pressure and, wherever possible, velocity of liquid plugs, their length and temperature distribution within them. The simulation results agree with the experiment for different input powers. Temperatures are predicted with a maximum deviation of 7%. Pressure variation trend is qualitatively captured as well as the liquid plug velocity, length and temperature distribution. The model also shows the ability of capturing the instant when the fluid pressure begins to oscillate after the heat load is supplied, which is a fundamental information for the correct design of the engineering model that will be tested on the ISS. We also reveal the existence of strong liquid temperature gradients near the ends of liquid plugs both experimentally and by simulation. Finally, a theoretical prediction of the stable functioning of a large diameter PHP in microgravity is given. Results show that the system provided with an input power of 185W should be able to reach the steady state after 1min and maintain a stable operation from then on.

Capillary instability of a two-layer annular film: an airway closure model

Capillary instability of a two-layer liquid film lining a rigid tube is studied computationally as a model for liquid plug formation and closure of human airways. The two-layer liquid consists of a serous layer, also called the periciliary liquid layer, at the inner side and a mucus layer at the outer side. Together, they form the airway surface liquid lining the airway wall and surrounding an air core. Liquid plug formation occurs due to Plateau–Rayleigh instability when the liquid film thickness exceeds a critical value. Numerical simulations are performed for the entire closure process, including the pre- and post-coalescence phases. The mechanical stresses and their gradients on the airway wall are investigated for physiologically relevant ranges of the mucus-to-serous thickness ratio, the viscosity ratio, and the air–mucus and serous–mucus surface tensions encompassing healthy and pathological conditions of a typical adult human lung. The growth rate of the two-layer model is found to be higher in comparison with a one-layer equivalent configuration. This leads to a much sooner closure in the two-layer model than that in the corresponding one-layer model. Moreover, it is found that the serous layer generally provides an effective protection to the pulmonary epithelium against high shear stress excursions and their gradients. A linear stability analysis is also performed, and the results are found to be in good qualitative agreement with the simulations. Finally, a secondary coalescence that may occur during the post-closure phase is investigated.

Experimental investigation of flow characteristics in a vertical vibration two-phase loop thermosyphon

In this paper, flow characteristics of a two-phase loop thermosyphon under vertical reciprocating vibration are visually investigated with N-pentane as the working fluid. The tests are performed for a heating power range of 20 W to 40 W, the filling ratio of 30 % to 70%, and a 30 m?s-2, 35 Hz vertical reciprocating vibration. The effect of vertical vibration on flow characteristics of the two-phase loop thermosyphon is investigated by comparing the obtained results with those acquired in static, thereby providing a basis for explaining the heat transfer process of two-phase loop thermosyphon under vibration. The results indicate that vertical vibration promotes the rupture of a liquid plug and the transformation of the plug flow to annular flow or wavy flow. Furthermore, the vertical vibration does not change the distribution law of liquid flow velocity in the two-phase loop thermosyphon. However, it will reduce the overheating and flow velocity in the two-phase loop thermosyphon at the start-up. With an increase in the heating power, the influence of vertical vibration on liquid flow velocity is reduced due to continuous disturbance of the working medium in the two-phase loop thermosyphon.

Influence of the Liquid Plug on the Heat Transfer Performance of the Ultra-Thin Flat Heat Pipe

Influence of the Liquid Plug on the Heat Transfer Performance of the Ultra-Thin Flat Heat Pipe

Taylor vortex center, film thickness, velocity and frequency of circulations in slugs and plugs for non-Newtonian and Newtonian fluids in two-phase Taylor flow in microchannels

Based on the recently published mathematical model for non-Newtonian two-phase flow in microchannels (Abiev, 2022) an extension that allows to calculate the majority of important parametersof two-phase Taylor flow for non-Newtonianfluids was developed and is presented in this paper. The following parameters could now be calculated theoretically for two-phase Taylor flow of non-Newtonian fluids(both for liquid slug and liquid plug): (i) the center of Taylor vortices, (ii) their boundaries, (iii) mean velocitiesand frequency of circulation, (iv) mean velocities in by-passand transit films, and (v) transition from circulation to by-pass flowconditions. The coincidence with the Newtonian fluids as a limiting case was evaluated.The obtained results represent crucial input data for the three-layer mass transfer model, the frequency of circulation-basedmass transfermodel,and are useful for the understanding of the influence of various parameters on heat and mass transfer intensity in Taylor flows.