Increase In Liquid Viscosity Research Articles

Pinch-off of a regular bubble during the impact of droplets on a liquid pool

A droplet impacting a liquid pool can result in the pinch-off of a regular bubble. In this study, the cavity deformation and regular bubble pinch-off after droplets impacting a liquid pool were experimentally investigated. The results indicate that the phenomenon of regular bubble pinch-off results from the combined effects of cavity expansion and capillary wave propagation. The inertial force, viscous force, and droplet diameter are all crucial to the cavity evolution and the process of regular bubble pinch-off. The cavity depth increases with the droplet's inertial force but does not change with the droplet's viscous force. As the droplet's inertial force increases, the diameter of the regular bubble first increases and then decreases. The diameter of the regular bubble at We = 165 is almost four times that at We = 193. In addition, the peak size of the regular bubble decreases as the liquid viscosity increases, but increases as the droplet diameter increases. These variations in the regular bubble size are explained using a theoretical analysis. Finally, the effects of the inertial and viscous forces on the thresholds between no-bubble and regular-bubble pinch-off regimes are studied. As the Ohnesorge number increases from 1.37 × 10−2 to 2.03 × 10−2, the upper and lower critical Weber numbers for the occurrence of the regular bubble pinch-off can increase by 30 and 25, respectively. The theoretical boundaries of regular bubble pinch-off agree well with the boundaries observed in the experiments.

Research on particle migration in fractures driven by gas-liquid two-phase flow during deep energy storage and extraction

Particle-laden fluid flow in fracture encompasses various deep geo-energy projects, including but not limited to hydraulic fracturing, mud and water inrush, and sand production. The migration of particles under fluid flow seriously affects the stability of geo-energy engineering and understanding the mechanisms is of great importance. This study presents a numerical investigation of particle-laden fluid flow in rock fractures under two-phase flow. A coupled approach of resolved computational fluid dynamics (CFD) and discrete element method (DEM) is employed to capture the particle movements and variations in hydraulic properties, with the volume of fluid (VOF) method to reproduce the two-phase flow. The results indicate that the model with gas injection exhibits higher particles migration velocity compared to that without gas due to the increase in fluid velocity and fluctuation in drag force. Particles migration velocity presents an initial increase followed by a subsequent decrease as the gas fraction increases, which can be attributed to the initial rise followed by a subsequent decline in the drag force. In addition, the sensitive analysis shows that the particle migration velocity decreases with the increase of liquid viscosity and fracture roughness in the fluid, and further accelerates with the increase of particle size and hydraulic gradient. Our results have important implications for understanding the mechanisms of particle migration in rock fractures driven by the multiphase flow during deep energy storage and extraction.

Numerical simulation study on multiphase flow pattern of hydrate slurry

The research on the multiphase flow characteristics of hydrate slurry is the key to implementing the risk prevention and control technology of hydrate slurry in deep-water oil and gas mixed transportation system. This paper established a geometric model based on the high-pressure hydrate slurry experimental loop. The model was used to carry out simulation research on the flow characteristics of gas-liquid-solid three-phase flow. The specific research is as follows: Firstly, the effects of factors such as slurry flow velocity, hydrate particle density, hydrate particle size, and hydrate volume fraction on the stratified smooth flow were specifically studied. Orthogonal test obtained particle size has the most influence on the particle concentration distribution. The slurry flow velocity is gradually increased based on stratified smooth flow. Various flow patterns were observed and their characteristics were analyzed. Secondly, increasing the slurry velocity to 2 m/s could achieve the slurry flow pattern of partial hydrate in the pipeline transition from stratified smooth flow to wavy flow. When the flow rate increases to 3 m/s, a violent wave forms throughout the entire loop. Based on wave flow, as the velocity increased to 4 m/s, and the flow pattern changed to slug flow. When the particle concentration was below 10%, the increase of the concentration would aggravate the slug flow trend; if the particle concentration was above 10%, the increase of the concentration would weaken the slug flow trend, the increase of particle density and liquid viscosity would weaken the tendency of slug flow. The relationship between the pressure drop gradients of several different flow patterns is: slug flow > wave flow > stratified smooth flow.

Impact dynamics of a viscous drop containing a particle

When a particle is attached under a liquid drop by surface tension, it forms a solid–liquid compound drop. We investigate experimentally the impact dynamics of this compound drop onto a solid surface. After impact, the particle rebounds from the solid surface and rises through the drop. The particle can either remain in the deposited liquid at low impact velocities or separate from the drop above a critical impact velocity. We demonstrate here that as the liquid viscosity increases, this separation threshold transitions from a capillary threshold, characterized by a critical particle Weber number, to a viscous threshold, captured by a critical particle Stokes number. However, the particle can still separate from the drop below this viscous limit if the particle is shifted away from the axis of symmetry before the impact of the compound drop. This shifting is observed experimentally at large falling heights, where the particle is destabilized by the air drag. In addition, we show that the shifting of the particle can also induce an inclination in the vertical liquid jetting, with a tangent of its angle proportional to the shifting distance of the particle. Finally, we confirm the focusing mechanism responsible for this liquid jetting by combining the observations of two synchronized cameras, from side view and bottom view.

Numerical study of the geometric characteristics and kinetic behavior of single bubble rise processes in different liquids

The characterization of single bubble in gas–liquid two phase flow is a critical yet unresolved issue in both science and industry. In this study, the volume-of-fluid (VOF) method is used to numerically simulate and experimentally investigate the effect of initial bubble diameter, liquid viscosity, and surface tension on bubble deformation and the internal flow field of the bubble in a pool of stationary liquid. The findings indicate that as liquid viscosity increases, the bubble's rising speed decreases, and the bubble tends to oscillate. The variation in bubble deformation ratio and the degree of fluctuation increase with the bubble's initial diameter and decrease with the viscosity of the liquid phase. Additionally, as the surface tension of the liquid decreases, the bubble becomes more prone to rupture, and the number of ruptures increases. The flow field inside the bubble can be classified into three categories: “double main vortex type,” “double main vortex type with separated vortex,” and “double main vortex type with scattered vortex.” The velocity reaches its maximum at the center of each vortex type, and the velocity at the interface varies as the bubble interface shape changes. This work lays the foundation for the study of the flow field inside the bubble and improves the predictability of gas–liquid equipment design.

Heat flux characteristics of a single droplet splashing on the liquid film obtained with a thermal lattice Boltzmann method

The double-distribution-function thermal lattice Boltzmann method is employed to investigate the heat flux characteristics of single droplet impact on a liquid film above a heated wall. The effects of impact velocity, liquid film thickness, droplet radius, and viscosity coefficient on the average and instant heat flux distribution are analyzed. The droplet impact first breaks the steady-state thermal boundary layer in the impact region, causing the heat flux in the wall impact region to increase. This is because the temperature gradient between the liquid film and the wall increases as the droplet dives downward and expands. The velocity discontinuity at the liquid jet sheet prevents the transfer of the transverse velocity in the liquid film to the static region, yielding a transition region. Convective heat transfer is dominant in the impact and transition regions, while conductive heat transfer is dominant in the static region. Moreover, a large impact velocity promotes the synergy between the temperature and flow velocity fields, enhancing the heat transfer efficiency. The kinetic energy consumption of the droplet increases with the liquid film thickness, which causes the heat flux to decrease. The effect of droplet radius on the heat flux at the wall is minimal. Furthermore, an increased liquid viscosity is not beneficial for wall heat dissipation.

Experimental Study on Bubble Dynamics and Mass Transfer Characteristics of Coaxial Bubbles in Petroleum-Based Liquids.

Petroleum-based liquids are from an important petroleum-based polymer, whose application and preparation involve multiple operations related to gas-liquid two-phase flow. Due to insufficient research on gas-liquid two-phase flow, there is a gap in bubble dynamics and mass transfer characteristics in petroleum-based liquids. Accordingly, we have systematically investigated the bubble formation process, bubble rising dynamics, and mass transfer of coaxial bubbles. Herein, the contour of bubbles was obtained for analyzing the bubble formation process. It was found that the increase of gas flow rate contributed to the increase of bubble generation size, while the liquid viscosity had an inhibitory influence on the increase of bubble generation size. Moreover, the variation of bubble rising velocity was considered and the force analysis of the rising bubble was provided. A new model of drag coefficient applicable to petroleum-based liquids was proposed. Finally, variations in the amount of dissolved oxygen in the liquid were measured to analyze the mass transfer characteristics. The increase in nozzle inner diameter and gas flow rate both promoted mass transfer, but the increased liquid viscosity hindered mass transfer.

Effect of liquid viscosity on the gas–liquid two phase countercurrent flow in the wellbore of bullheading killing

Studying the gas–liquid two-phase countercurrent flow under high liquid viscosities is key in designing the well-killing parameters of the bullheading method; however, currently, in-depth research on this issue is limited. Herein, using a self-designed vertical visualization wellbore gas–liquid two-phase flow experimental system with a tube diameter of 0.1 m and liquid viscosity in the range of 1–50 mPa s, a simulation experiment of bullheading killing was conducted. The effects of liquid viscosity on the bubble morphology, bubble migration, and gas–liquid countercurrent flow pattern were analyzed, and the mechanism of back pressing of gas during the well-killing process of the bullheading method in a large-scale tube was revealed. Moreover, the influencing factors and variation in the critical displacement of bullheading were analyzed. The results revealed that the stability of Taylor bubbles increased and the number of small bubbles decreased with the increase in liquid viscosity, resulting the gradual shrinkage or disappearance of the churn flow and bubbly flow, expansion of the region of slug flow, and downward movement of the transition boundary between bullet-cup flow and slug flow. On approaching the critical liquid displacement during the process of simulated bullheading, Taylor bubbles rapidly dissociated into small bubbles and turned around during the rising process, forming a gas–liquid downward flow, following which the gas was successfully pressed back. In addition, our analysis revealed that the press-back effect is not always positively correlated with the viscosity of the kill fluid. The critical displacement of the well-killing fluid first decreased and then increased with an increase in the liquid viscosity. Finally, based on the experimental results, an improved calculation method for the critical displacement of bullheading considering the influence of liquid viscosity was established, which could provide important theoretical guidance for the parameter design of bull heading.

Experimental investigation of the particle growth mechanism and influencing factors during granulation process by pyrohydrolysis in fluidized bed

Particle growth kinetics during the pyrohydrolysis of pickling waste liquor in fluidized bed has an important influence on the metal oxide recovery. This study innovatively investigates the particle growth mechanism by combining granulation characteristics in fluidized bed and collision behavior between droplet and heated spherical particle, and then explores the effect of operating parameters on particle growth and powder properties adhered on the surface in the fluidized bed at 800 ℃. The results indicated that the particle growth mechanism was highly dependent on the bed temperature. When T < 100 ℃, it was mainly based on the direct droplet deposition on the surface; at 100 ℃< T < 300 ℃, droplet deposition and powder collision adhesion together promoted particle growth; when T > 300 ℃, the powder adhesion by inertia collision was dominant. The change in particle growth mechanisms was attributed to the liquid-solid interactions. The increasing particle temperature promoted rebound and breakup of droplets after impacting with the particles and then led to fine powder formation in the bed gaps. However, the increase of liquid viscosity was beneficial for the direct adhesion of droplets to the particle surface and accelerated particle growth. The results also found that operating parameters had a significant effect on the granulation characteristics. The coating layer thickness, powder size and porosity all increased with bed temperature. When the bed temperature is 800 ℃, the size of powder and bed particles both increased with the concentration of Fe3+ but decreased with the atomized gas velocity. However, the increase in liquid flow rate led to slower particle growth because of the increase in superheated vapor volume.

An experimental study on the effect of liquid properties on the counter-current flow limitation (CCFL) during gas/liquid counter-current two-phase flow in a 1/30 scaled-down of Pressurized Water Reactor (PWR) hot leg geometry

To promote the safety of the nuclear reactors, numerous authors have carried out investigations of gas/liquid counter-current two-phase flow in order to understand the characteristics during the inception of flooding or CCFL. The present work covers an experimental and analytical study on the effect of liquid properties on CCFL characteristics in a complex geometry representing 1/30 scaled-down version of a German-Konvoi PWR hot leg. The obtained results reveal that the gas velocity to initiate the flooding monotonically decreases with the increase of the liquid velocity. At high liquid flow rates, it is noticed that with the increase of glycerol percentage, the gas flow rate needed to initiate the flooding significantly decrease due to either the increase in liquid viscosity or the decrease in corresponding surface tension. Here under the same flow condition, the flooding is initiated faster by the higher glycerol percentage. Moreover, instead of the well-known Wallis superficial velocity, the Kutateladze-type parameter or a combination of the Wallis parameter and liquid property numbers by Zapke & Kröger (1996) which were previously proposed by numerous authors to investigate the effects of liquid properties on CCFL characteristics, a modified non-dimensional Wallis parameter combined with the inverse viscosity number introduced by Ma et al. (2020) is found herein to more accurately correlate the present experimental data. Through a dimensional similarity analysis, a new empirical correlation reveals that the liquid Froude number is the greatest determinant of CCFL characteristics with respect to the effect of the liquid properties.

Evolution of mesoscale structure in fluidized beds with non-spherical dry and wet particles

Instantaneous force distributions at bubble boundaries in non-spherical dry and wet particle systems. • The force distributions at bubble boundaries are analyzed to explain the influence mechanism of different shapes of bubbles in non-spherical dry and wet particle systems. • The effects of particle aspect ratio and liquid viscosities are investigated through the force analysis and factorial analysis. • With the increase of the particle aspect ratio, the bubble equivalent diameter gradually increases. • As the liquid viscosity increases, the bubble frequency gradually decreases. Fluidized beds with non-spherical dry and wet particles are widely used in industrial processes, and the mesoscale structure in the bed has an important influence. In this study, CFD-DEM simulations are performed to evaluate the flow behaviors and mesoscale structure in fluidized beds with non-spherical dry and wet particles. The accuracy of the model is validated by comparison with the results of the particle image velocimetry experiment. The force distributions at bubble boundaries are analyzed to explain the influence mechanism of different shapes of bubbles in non-spherical dry and wet particle systems. The factor analysis indicates the interaction of particle shape and viscous liquid on the translational and rotational kinetic energy of particles. When the bed height is low, as the particle aspect ratio increases, the bubble equivalent diameter gradually increases. In addition, as the liquid viscosity increases, the particle and bubble granular temperature gradually decrease, indicating the reduction of particle velocity fluctuate and the decrease of turbulent kinetic energy of bubble. These findings have guiding significance for the fluidization of non-spherical dry and wet particles and can be used to optimize related industrial processes.

How dynamic adsorption controls surfactant-enhanced boiling

Improving boiling is challenging due to the unpredictable nature of bubbles. One way to enhance boiling is with surfactants, which alter the solid–liquid and liquid–vapor interfaces. The conventional wisdom established by previous studies suggests that heat transfer enhancement is optimized near the critical micelle concentration (CMC), which is an equilibrium property that depends on surfactant type. However, these studies only tested a limited number of surfactants over small concentration ranges. Here, we test a larger variety of nonionic and anionic surfactants over the widest concentration range and find that a universal, optimal concentration range exists, irrespective of CMC. To explain this, we show that surfactant-enhanced boiling is controlled by two competing phenomena: (1) the dynamic adsorption of surfactants to the interfaces and (2) the increase in liquid dynamic viscosity at very high surfactant concentrations. This dynamic adsorption is time-limited by the millisecond-lifetime of bubbles on the boiling surface—much shorter than the timescales required to see equilibrium behaviors such as CMC. At very high concentrations, increased viscosity inhibits rapid bubble growth, reducing heat transfer. We combine the effects of adsorption and viscosity through a simple proportionality, providing a succinct and useful understanding of this enhancement behavior for boiling applications.

Experimental study of influence of liquid viscosity in horizontal slug flow

Slug flow is present in many industrial processes, including the ones related to the petroleum industry. Such flow pattern is characterized by the periodic passage of liquid slugs that may or may not be aerated and elongated bubbles that flow atop a liquid film. Most of the existing models for slug flow have been developed for two-phase water–air flows but, in oil and gas production, the liquid phase is often substantially more viscous than water. The aim of this article is to evaluate the effect of the liquid viscosity increase on slug flow. To achieve this goal, an experimental study on liquid–gas flows in a 26-mm ID, 8.65-m long horizontal pipe was developed. Water and mixtures of water and glycerin (μL≈5.46, 10.27, 15.39, 20.33 and 30.37 cP) made the working liquids. The experimental results from the high-speed camera and resistivity sensors enabled a detailed investigation of elongated bubble characteristics and slug flow parameters. The elongated bubble nose deformation, the appearance of plunging jets and the deformation of the dispersed bubbles are associated to dimensionless numbers. Experimental results show that the dispersed bubble deformation in the slug, the number of fragmented bubbles in the slug and the elongated bubble velocity increase as the mixture velocity and the liquid viscosity increase. The effects on the slug frequency and slug length depend on the superficial velocities of the fluids.

A novel approach for measuring particle settling and settled bed build-up velocities in concentrated slurries using electrical resistance tomography

Electrical Resistance Tomography (ERT) has been used to detect different phases based on differences in conductivities in multiphase systems. For the first time, ERT is used in this work to study solids settling and settled bed build-up velocities in a slurry of glass particles and glycerol solution. It measures the particles' position via mixture conductivities, which determine solids concentration at different heights. Development of the solids settling velocity model relies on the movement of particles instead of tracking the solid-liquid interface. Experimental solids settling velocity value decreases with increasing solids concentration and liquid viscosity, agreeing with estimations from Richardson and Zaki's model. The settled bed build-up model uses mass balance and ERT data to predict build-up velocity, which increases with increasing solids concentration and decreasing liquid viscosity. Results demonstrate that, as a direct and non-invasive method, ERT could simultaneously measure the solids settling and settled bed build-up velocities in slurries. • Electrical Resistance Tomography is used to measure solids settling velocity. • Settling velocity decreases as solid concentration and liquid viscosity increase. • Settled bed buildup velocity model developed using tomography data. • Βuildup velocity is higher at higher solids concentration and lower viscosity. • A relationship between solids settling and buildup velocities is established.

Boundary layer combustion of HTPB/paraffin fuels for hybrid propulsion applications

HTPB/paraffin fuels exhibit high regression rates and excellent mechanical properties due to the droplet entrainment and enhancement of the HTPB matrix, however, the special structure of the fuels also leads to more complex combustion mechanisms that may be quite different from that of paraffin and HTPB alone. The boundary layer combustion characteristics of HTPB/paraffin fuels with oxygen flow in a windowed 2D slab burner were investigated by using a high speed camera, Schlieren and thermocouples. The results demonstrated that the regression rate of HTPB/paraffin fuels mainly composed of paraffin was higher than that of HTPB due to the dominant role of droplet entrainment in mass transfer. The flame height and combustion boundary layer thickness of the fuel were inversely correlated with the oxidizer mass flux, and decreased by about 2.8 times and 2.5 times when the oxidizer mass flux increased from 12.40 kg⋅m⋅−2s−1 to 64.86 kg⋅m⋅−2s−1, respectively, however, the chamber pressure exhibited little effect. The addition of HTPB limited the development of combustion boundary layer thickness and hindered the generation of entrainment droplets due to an increase in liquid layer viscosity, but both the proportion of flame area in the combustion boundary layer and the gas temperature gradient in the fuel-rich zone were positively correlated with HTPB content attributed to the higher combustion efficiency.

Dissolution mechanism of magnesium aluminate spinel in copper smelting slag based on the shrinking core reaction models of corrosion

MgAl2O4 spinel is a critical raw material in spinel refractory production. However, the dissolution behavior of the spinel and its interactions with Cu smelting slag have not been previously studied in detail in terms of thermodynamics and kinetics. Therefore, to investigate the interactions of MgAl2O4 spinel in Cu smelting slag, MgAl2O4 spinel was simulated in Cu smelting slag using FactSage. Additionally, the dissolution mechanism of MgAl2O4 spinel in Cu smelting slag was studied via a slag immersion method. It was found that the Fe ions of the Cu smelting slag diffused mutually with the Mg2+ and Al3+ in the spinel, and the final products of the spinel reaction with the slag were ASpinel (Mg1-xFexAl2-yFeyO4) solid solution and liquid slag phases. The dissolution mechanism was consistent with the shrinking core reaction models. In the early stage of dissolution, ASpinel (Mg1-xFexAl2-yFeyO4) was generated at the interface, and the dissolution mechanism was controlled by the rate of solid solution phase generation, with an activation energy of E1 = 153.17 kJ/mol. At the later stage of dissolution, the Fe ions continued to diffuse into the spinel through the solid solution phase, while the spinel dissolved into the slag, and the dissolution mechanism was controlled by the rate of boundary migration of the solid solution phase, with an activation energy of E2 = 110.84 kJ/mol. Meanwhile, this interdiffusion behavior led to an increased liquid viscosity compared to that of the original slag that could further slow slag infiltration. The spinel could absorb Fe ions, rendering it a promising candidate for use in the Cu industry in the field of chromium-free refractories.

Hydrodynamics and Scaling Laws of Gas–Liquid Taylor Flow in Viscous Liquids in a Microchannel

The hydrodynamics of gas–liquid Taylor flow in microchannels is vital to the microreactor’s application, but its characteristics in viscous liquids are rarely reported. Accordingly, this study concentrates on the characteristics of bubble behavior in viscous liquids (45.6–240.5 mPa·s). The results show that the viscosity effect could dominate the bubble morphology. Importantly, considering the liquid film distribution, a novel parameter as the equivalent liquid film thickness is proposed for the square microchannel and it is strongly related to the capillary number and gas–liquid flow rate ratio. Besides, the bubble velocity first decreases to a minimum value and then becomes faster with the flow rate of the liquid, and the ideality of the multiphase system decreases with the increase of liquid viscosity and pressure drop. Finally, the viscosity term is introduced to the pressure drop equation based on the Lockhart–Martinelli type. This work enriches the understanding of the viscosity effect on gas–liquid microflows.

Statistical characterization of the interfacial behavior of the sub-regimes in gas-liquid stratified two-phase flow in a horizontal pipe

The aim of the present study was to identify the interfacial behavior of the sub-regime of gas-liquid stratified two phase flow by using the pressure differential signal data. Here, the probability distribution function (PDF), power spectral density (PSD), kolmogorov entropy and discrete wavelet transform (DWT) were used to analyze the differential pressure signals. The indicators of each flow sub regime were analyzed on the basis of the quantitative values of the statistical curves, which were also validated by visual observation of the video images. The results indicated that there are six identified sub-regimes of stratified flow namely stratified smooth (S), two-dimensional (2-D) wave, three-dimensional (3-D) wave, roll wave (RW), entrained droplet + disturbance wave (ED + DW) and pseudo slug (PS). Next, the increase of liquid viscosity will shift the transition line from the RW to ED + DW to a lower both of JL and JG. The increase of the liquid viscosity provides a stabilizing effect to reduce the chaos of the pressure gradient fluctuation. For the RW and the ED + DW sub-regime, the increase of the liquid viscosity shifts the wavelet energy to a larger scale and lower frequency. For the PS sub-regime, the increase of liquid viscosity shifts the wavelet energy to a smaller scale with a higher frequency. For the RW sub-regime, the increase of JG will increase the wavelet energy at the small-scale and high-frequency decomposition levels.

Experimental investigation of liquid viscosity's effect on the flow behaviour and void fraction in a small diameter bubble column: How much do we know?

The viscosities of heavy oils and bitumen are significantly above those of water and light crude oil and are found in the oil and gas, polymer, metallurgical, and process industries. Unfortunately, little research attention has been given to the void fraction, and the behaviours of such flows as bubbles rise over them in bubble columns. How the liquid viscosity influences the behaviour of these flows and void fraction were examined using the electrical capacitance tomography (ECT), level swell technique and visual technique with a high-speed camera. It was found that: an excellent agreement was achieved within ±10% for comparison between the obtained void fraction using both techniques for all the liquid viscosities considered. In contradiction to previous findings, an increase in liquid viscosity provokes a corresponding increase in the void fraction, yet the influence is seen to reverse for gas superficial velocities beyond 0.25 m/s. In concordance with Mori et al. (1999)'s observations, a liquid viscosity increment brings about a corresponding decrease in the bubble frequency. The Taylor bubble's rise velocity was heavily dependent on the liquid viscosity range, whereby increases in liquid viscosity bring about a rise in the flow distribution coefficient. The bubble drift velocity, on the contrary, reduces with increasing liquid viscosity.

Experimental investigation on the distribution characteristics of droplets in annular flow with wide liquid viscosity range

The existence of droplets in an annular flow has a non-negligible influence on the mass transfer and heat transfer between phases, and a phase property, such as liquid viscosity, can dominate the droplet characteristics. However, the effects of liquid viscosity on droplets have not yet received sufficient attention. In this study, the distribution characteristics of droplets in a vertical annular flow with a liquid viscosity of 1–30 mPa·s are experimentally investigated using a particle dynamic analyzer. The results reveal that the diameter and momentum of the droplet undergo two different changes during the increase of liquid viscosity, μL. In the low-liquid-viscosity range (μL < 10 mPa·s), the diameter and momentum of the droplet increase significantly with an increase in viscosity, whereas in the high-liquid-viscosity range (μL ≥ 10 mPa·s), their dependence on viscosity is considerably low. Owing to the different degrees of aggregation and fragmentation of droplets under different liquid viscosities, the radial evolution of droplets also show obvious distinctions. In addition, the slip ratio of the droplet velocity under different liquid viscosities is determined. When the liquid viscosity increases from 1 to 30 mPa·s, the droplet velocity decreases by 20.3% on average in the gas velocity range of 25–58 m/s, and small droplets have a relatively higher velocity and velocity range. Further, on the experiments show that the droplet deformation increases sharply with an increase in liquid viscosity because of the change in droplet generation mechanisms. The minimum proportion of the spherical droplet reduces to 9.2% at μL= 30 mPa·s, indicating that the droplet cannot be simply regarded as spherical when calculating the mass and heat transfer with high liquid viscosity. Finally, the present results can assist in multiphase flow modeling under high-viscosity conditions.