Slip Velocity Research Articles

Modeling and analyzing the influence of slip velocity on joint surface

Millions of joints are utilized in large-scale equipment to interconnect components. However, the intricate nonlinear mechanical behavior exhibited at joint interfaces poses challenges in accurately modeling equivalent joints. The Jenkins element with viscoelasticity is built upon the Iwan model, and a novel Iwan-Stribeck-RIPP (Reduced Iwan Plus Pinning) model is proposed to depict the slip velocity and pinning effects concurrently. Analytical expressions for force-displacement, energy dissipation-displacement, and force-energy dissipation under microslip and macroslip were derived. A joint interface experimental platform was constructed to reveal the influence of slip velocity on the joint interface. The results indicate strong alignment between the analytical solution of the Iwan-Stribeck-RIPP model and the experimental outcomes of the joint interface. Moreover, the model effectively captures both slip velocity and pinning effects. Introducing slip velocity into the new model promises to enhance the accuracy of force-displacement analysis at the joint interface. This enhancement is attributed to the inclusion of both frictional energy and kinetic energy dissipation resulting from the slip velocity in the analytical model of the joint structure.

Analytical Solution for Transient Electroosmotic and Pressure-Driven Flows in Microtubes

This study focuses on deriving and presenting an infinite series as the analytical solution for transient electroosmotic and pressure-driven flows in microtubes. Such a mathematical presentation of fluid dynamics under simultaneous electric field and pressure gradients leverages governing equations derived from the generalized continuity and momentum equations simplified for laminar and axisymmetric flow. Velocity profile developments, apparent slip-induced flow rates, and shear stress distributions were analyzed by varying values of the ratio of microtube radius to Debye length and the electroosmotic slip velocity. Additionally, the “retarded time” in terms of hydraulic diameter, kinematic viscosity, and slip-induced flow rate was derived. A simpler polynomial series approximation for steady electroosmotic flow is also proposed for engineering convenience. The analytical solutions obtained in this study not only enhance the fundamental understanding of the electroosmotic flow characteristics within microtubes, emphasizing the interplay between electroosmotic and pressure-driven mechanisms, but also serve as a benchmark for validating computational fluid dynamics models for electroosmotic flow simulations in more complex flow domains. Moreover, the analytical approach aids in the parametric analysis, providing deeper insights into the impact of physical parameters on electroosmotic and pressure-driven flow behavior, which is critical for optimizing device performance in practical applications. These findings also offer insightful implications for diagnostic and therapeutic strategies in healthcare, particularly enhancing the capabilities of lab-on-a-chip technologies and paving the way for future research in the development and optimization of microfluidic systems.

Research on the generalization issue of the heterogeneous QC-EMMS drag model for gas-solid fluidization

In the circulating fluidized bed (CFB), the non-uniform mesoscale structure formed by the particle clustering effect causes a substantial decrease in the gas-solid drag. Since the degree of particle clustering varies with operating conditions, an accurate drag model needs to be universal in different heterogeneous flow conditions. In this study, the relationships between the Ψ factor in clusters' solid holdup model that characterizes the flow non-uniformity and the operating parameters of CFB (including slip velocity Reynolds number, Re*, bed-averaged solid volume fraction, εs,bed, and solid mass circulation rate, Gs) are established. It improves the adaptability of the QC-EMMS drag model under different working conditions. In previous research, we established two types of models that related Ψ factor to Re* and εs,bed respectively. However, there exists a problem of high dispersion of points, indicating that the selected parameters cannot fully describe the flow non-uniformity. Therefore, Gs is reintroduced to modify the two types of models. The results show that the prediction accuracy of the modified models is improved and the relative error is <10%, indicating that the non-uniform factor Ψ has a strong correlation with Gs. In addition, the quantitative relation between Re*, εs,bed, and Gs is derived from modified models, and the trend of relation is highly consistent with the fluidization diagram proposed by Yerushalmi J., which verifies the accuracy of modified models. Finally, numerical simulation of typical CFB cases proves the adaptability of the modified models in wide operating conditions of fluidization.

Numerical simulation for the slip impacts on the radiative nanofluid flow over a stretched surface with nonuniform heat generation and viscous dissipation

Abstract The growing fascination with nanofluid flow is motivated by its potential applications in a variety of industries. Therefore, the objective of this research article is to conduct a numerical simulation of the Darcy porous medium flow of Newtonian nanofluids over a vertically permeable stretched surface, considering magnetohydrodynamic mixed convection. Various attributes, such as the impacts of slip, thermal radiation, viscous dissipation, and nonuniform heat sources, are integrated to explore the behavior of the flow. The utilization of the boundary layer theory helps to describe the physical problem as a system of partial differential equations (PDEs). These derived PDEs are then converted to a system of ordinary differential equations (ODEs) through the application of suitable conversions. The outcomes are obtained using the finite difference method, and the effects of parameters on nanofluid flow are compared and visualized through both tabular and graphical representations. The outcomes have been computed and subjected to a comparative analysis with previously published research, revealing a remarkable degree of agreement and consistency. Consequently, these innovative discoveries in heat transfer could prove beneficial in addressing energy storage challenges within the contemporary technological landscape. The noteworthy main findings indicate that when the porous parameter, magnetic number, velocity slip parameter, viscosity parameter, and Brownian motion parameter are assigned higher values, there is an observable expansion in the temperature field. Due to these discoveries, we can enhance the management of temperature in diverse settings by effectively modulating the heat flow.

Thermally oscillatory flow inside an irregular channel through a porous medium with velocity and temperature slips

The purpose of this exploration is to scrutinize the heat transfer characteristics of oscillatory flow on the magnetized second-grade fluid within an asymmetric porous wavy channel with velocity slip and temperature jump conditions. Flow in porous space is characterized by modified Darcy's law. The use of a magnetized second-grade fluid in an asymmetric porous wavy channel could potentially enhance heat transfer within the fluid, leading to better control over drug release rates and spatial distribution. The fundamental flow equations are converted into ordinary differential equations (ODEs) utilizing suitable non-dimensional variables and then resolved analytically. The outcomes are graphically represented to illustrate the physical impacts of governing parameters on the temperature, and velocity profiles. Streamlines are also constructed for specific physical parameters to investigate trapping phenomena. In addition, variations on the coefficient of skin friction, mass flux, and heat transfer coefficients are illustrated with different values of pertinent parameters. The outcomes indicate that fluid velocity is enhanced by increasing the values of Darcy's number and Grashof's number. The fluid temperature decreases by increasing the values of the temperature jump parameter.

Stability of fluid flow in a porous medium with uniform cross-flow and velocity slip

This work examines the evolution of small perturbations in a plane Poiseuille flow through a porous medium bounded by porous walls implemented with the Brinkman flow model. The effect of uniform cross-flow across the channel along with slip imposed on the channel walls is examined for the associated fluid flow. The modified Orr–Sommerfeld equation for the flow system under consideration is derived and then solved numerically using Chebyshev spectral collocation method. The acquired sufficient conditions ensure that fluid motion will remain stable even when the flow system is widely perturbed. The linear stability characteristics and the onset of instability is discussed for a wide range of cross-flow Reynolds number, slip length and porosity parameter. The above mentioned flow parameters have a significant stabilizing effect on the fluid flow that is depicted with neutral stability curves, growth rate dispersion curves and eigenspectrums. Asymmetric slip allows the critical Reynolds number to increase rapidly when the upper channel wall experiences more slip than the lower.

Porous structures impact on particle dynamics of non-Brownian and noncolloidal suspensions

This study aims to provide valuable insights into the impact of porous structures on particle dynamics in non-Brownian, non-colloidal suspension flows at very low Reynolds numbers. Two experimental approaches, Particle Image Velocimetry (PIV) with refractive index matching and Optical Flow Tracking Velocimetry (OFTV) were employed to analyze very dilute suspensions over various porous media models. The study considered three different porous structures with permeabilities ranging from 0.7 to 0.9 and three different thicknesses ranging from 0.2 cm to 0.5 cm, while the suspension bulk volume fraction was maintained at 3 %. In the PIV analysis, we observed that decreasing the porous permeability resulted in the maximum velocity location within the free flow region moving closer towards the interface between the flow and the porous media. We further quantified the effect of the porous structure on the suspension by characterizing interface properties, such as dimensionless slip velocity, shear rate, and slip length. These interface properties were found to be influenced by both the thickness and permeability of the porous media. Next, we analyzed particle migration due to the presence of porous structures using OFTV for very dilute suspensions of 1 %, 2 %, and 3 %, considering a porous medium with known physical properties and thickness. The study revealed two local concentration maxima: one within the free flow region on top of the rod arrays used to create the porous structure and a second along the rods' centerline inside the porous media model.

Numerical investigation on slip velocity characteristics of gas-liquid two-phase flow in a multiphase pump under different blade tip clearance

Abstract It is significant to explore the slip velocity characteristics of two-phase in blade tip clearance (BTC) of multiphase pump for improving semi-open mixed-flow pump performance. On the ground of the Euler-Euler inhomogeneous model, a gas-liquid mixed-flow pump was taken as the research object. Using CFX software to simulate the flow field in the multiphase pump with conditions of the inlet gas void fraction (IGVF) are 10%, 20% and 30%. The slip velocity characteristics of gas-liquid two-phase in mixed-flow multiphase pump with different blade tip clearance sizes (BTCS) were analyzed. The results show that there is obvious slip velocity on blade leading edge (L.E.), trailing edge (T.E.) and pressure side (PS) of BTC of mixed-flow pump impeller. When BTCS is small, the slip velocity on the tip pressure side has little change along flow direction, but with the increase of BTCS, slip velocity on the tip pressure side will gradually increase. There is a positive correlation between slip velocity and the pressure gradient. The research results can provide significant guidance for optimization design of semi-open mixed-flow multiphase pump.

Investigating journal bearing characteristics incorporating variable viscosity, couple-stress lubricant, slip-velocity, magnetic fluid, and sinusoidal surface-texturing

This study contributes to the practical understanding of journal bearings by comprehensively exploring the impact of variable viscosity, sinusoidal surface texturing, slip velocity, magnetic fluid, and couple-stress lubricants on the pressure distribution. Utilising the Barus variable viscosity formula, incorporating ferrofluid as a magnetic lubricant, and employing the Finite Difference Method for numerical analysis, this research reveals insights such as increased load-carrying capacity and pressure distribution in textured bearings. The results indicate that a small distance ratio and high magnetic parameters increase magnetic pressure. Textured bearings increased the load-carrying capacity and pressure distribution by approximately 246 % and 165 %, respectively. In addition, the magnetic, couple-stress, piezo-viscosity, and maximal slip parameters increase the load. Reducing the bearing attitude angle improves the load-carrying capacity. The magnetic parameter increases the attitude angle, as does the slip parameter. High values of the couple-stress parameter reduce friction, particularly in the presence of a textured surface, and the presence of a textured surface amplifies this effect. The study highlights the influence of magnetic, couple-stress, piezo-viscosity, and slip parameters on the bearing's performance, offering valuable insights for optimising journal bearing designs and operations in various engineering applications.

Impact of random nanoscale roughness on gas-scattering dynamics.

The impact of nanoscale wall roughness on rarefied gas transport is widely acknowledged, yet the associated scattering dynamics largely remain elusive. In this paper, we develop a scattering kernel for surfaces having nanoscale roughness that distinctly characterizes the two major types of interactions between gas molecules and rough surfaces. Namely these are (a) the weak perturbations arising from the thermal motion of wall atoms, essentially gas-phonon collisions, which are captured by the well-established Cercignani-Lampis model, and (b) the hard collisions owing to the irregularities of the rough, static potential energy surface, which are generally described by the fully diffuse model. Drawing an analogy between wave-surface and gas-surface scattering, a pseudo Debye-Waller factor is incorporated into the modeling as a weighting coefficient to allow the transition between smooth and rough surface conditions. The proposed scattering kernel is validated through high-fidelity molecular dynamics simulations that are performed for systems with varying roughness, temperature, and gas-surface combinations. The results indicate that the model well captures the scattering dynamics of gas molecular beams impinging on surfaces at different velocities, specifically for the accommodation coefficients and reflection patterns. Additionally, in flow and heat transport cases, it accurately predicts macroscopic quantities such as velocity slip and temperature jumps across the range of tested conditions.

PIV experimental study on water-sediment two-phase flow in NACA0012 cascade

Abstract Sediment wear is one of the important reasons for the damage of hydraulic machinery components, and the motion characteristics of sediment are the key factors to determine the degree of wear damage. In order to reveal the mechanism of sediment wear of turbine guide vane, motion characteristics of sediment near the wall of NACA0012 cascade were studied by PIV test method. In this research, fluorescent and sediment particles were used as tracer particles respectively, and the particle images of solid and liquid phases were recorded by double-camera synchronous imaging method. Finally, the synchronous velocity field of solid and liquid phases was determined by correlation analysis of particle images. The experimental results show that the PIV test method can accurately determine the motion characteristics of the solid phase. There is velocity slip between the solid phase and the liquid phase, and the velocity deviation is related to the factors of particle characteristics and Reynolds number.

Multi-scale numerical analysis of Ca-based desulfurizer dynamics characteristics and SO2 absorption processes in industrial-scale SDA-FGD reactor

Spray dry absorption flue gas desulfurization technology is widely employed to control sulfur dioxide emissions from industrial pollutant gases. This study employs the multiphase particle-in-cell method to numerically simulate gas–solid heat transfer, SO2 removal processes, and the effect of operating conditions in the SDA reactor. The flue gas desulfurization model used has been experimentally validated. The results indicate that flue gas and slurry droplets exhibit swirling flow along the reactor walls, forming gas vortices at the top and near the outlet. The temperature and Reynolds number of slurry droplets show minimal variation when particle size is below 43 μm. The heat transfer coefficient of slurry droplets is notably higher at the reactor top and increases with the slip velocity of the droplets. Furthermore, the CaSO3 volume fraction increases with longer residence times of the slurry droplets in the reactor. When the height and diameter of the main reaction area are lower than 14 m and 8.5 m, respectively, the SO2 mass fraction in the central area undergoes significant changes. The SO2 inlet concentration is negatively correlated with desulfurization efficiency, whereas the slurry injection speed, along with the diameter and height of the main reaction region, are positively correlated with desulfurization efficiency. Among these factors, the SO2 inlet concentration and the height of the main reaction region have the most substantial impact on desulfurization efficiency.

Study on velocity profile of gas–liquid two-phase stratified flow in pipelines based on transfer component analysis-back propagation neural network

The measurement of cross-sectional velocity profile is a challenge in the field of two-phase flow. In this paper, the stereoscopic particle image velocimetry (SPIV) technique is employed to obtain the cross-sectional velocity profile of gas and liquid phase in stratified flow. Interface velocity profile is obtained through numerical simulation. By leveraging the concept of transfer learning, we propose to construct a transfer component analysis-back propagation network using stereo particle image velocimetry and numerical simulation and to predict the velocity profile of the gas–liquid interface in stratified flow. The research indicates that the cross-sectional velocity profile of the gas–liquid stratified flow is similar to the “mushroom” shape. The velocity profile of the gas–liquid interface changes from an M-type to the N-type, and the gas–liquid velocity slip affects the transformation process. With the increase in the gas-phase velocity, the distance between the two peaks of the M-type velocity profile increases and the gap between gas–liquid velocity peaks increases accordingly.

Duan Rach approach solution of MHD flow of ternary hybrid Casson magnetized nanofluid in converging/diverging geometry with velocity slip effects

This study explores the impact of ternary hybrid nanofluid and velocity slip on the Non-Newtonian fluid flow between two nonparallel plates. Additional influence of an applied magnetic field is considered with Casson fluid (Blood) as a base fluid. Both analytic and numerical techniques are employed to comprehensively analyze the system’s behavior under these combined effects. The governing partial differential equations (PDEs) governing continuity and momentum are simplified into a system of ordinary differential equations (ODEs) through similarity transformations. To obtain an explicit series solution for the resulting problem, we employ the Duan Rach approach (DRA). Subsequently, we conduct a thorough analysis of the solution’s convergence to ensure its reliability and accuracy. The same problem is also solved by using the Runge-Kutta-Fehlberg 4th–5th order approach featuring shooting technique and an excellent agreement is observed between the two sets of results. A comparison was made between the results obtained from this investigation in particular cases and the results obtained via the HAM-based Mathematica package for validation. Influence of various parameters of practical importance on the velocity and temperature profiles is studied and portrayed graphically. Values of skin friction coefficient are tabulated by assigning different values to various emerging parameters. It is found that the velocity slip parameter has a positive value in a converging channel, it implies that there is a slip between the fluid and the channel wall, and the slip velocity is directed in the same direction as the flow. Hence velocity increases. Also, results obtained reveal that for positive value of β + velocity gets high in converging case and lower velocity can be seen in diverging geometry. Same behavior is seen for β − .

Coating of micropolar fluid during non-isothermal reverse roll coating phenomena

Reverse roll coating is a high-speed coating process used in many applications. The single largest application for reverse roll coating is applying architectural paint to coils of sheet metal; however, in the converting industry reverse roll coating is used for some thermal coatings, adhesives, color laser paper receivers, wax coatings, magnetic coatings, vinyl dispersions for wallcovering, some specialty light sensitive applications, and many specialty products that require a high precision application process. This work presents a mathematical model for the steady flow of non-isothermal, incompressible, micropolar fluid in the metering nip of a reverse roll coater with velocity slip applied at both roll’s surfaces. Lubrication approximation theory (LAT) is utilized to reduce the complexity of the non-dimensional equations. Exact solutions for pressure gradient, velocity, and temperature are achieved. At the same time, numerical techniques (Simpson’s 3/8 rule with Newton Raphson method) are used to compute the pressure distribution, coating thickness, flow rate, and separation points. Effects of coupling number, slip parameter, microrotation, and velocity ratio on velocity, pressure, temperature, and pressure gradient are presented in graphs. It is observed from the current analysis that the intrinsic rotations of the fluid particles prove to be the controlling parameter of the pressure gradient, which significantly varies the coating thickness. Also, as a result of velocity slip, the flow rate declines and the coating thickness reduces as the fluid moves faster along the boundary walls.

Evolution of heat transfer in MHD nanofluid flow over a porous plate: Insights into the influences of slip and variable viscosity

Temperature-dependent viscosity finds application in various industries such as oil and gas, polymer processing, and food manufacturing. Understanding how viscosity changes with temperature is critical for optimizing processes like drilling operations, polymer molding, and food product consistency. Additionally, it plays a vital role in controlling flow behavior, ensuring efficient heat transfer, and maintaining product quality across different temperature conditions. The exploration of temperature-dependent viscosity in Powell-Eyring nanofluid models represents a novel and unexplored avenue in the field. The study’s novelty is underscored by its comprehensive investigation into a range of factors, such as surface suction, thermal radiation, slip velocity effects, and nanoparticle concentration slip, all integrated within the Powell-Eyring nanofluid model. Moreover, the adoption of bvp4c as a numerical tool further emphasizes the research’s unique contributions. The curves of temperature, concentration, and velocity as a consequence of changes in physical parameters are discussed. Increasing the value of the suction parameter promotes heat transfer but slows the velocity of the nanofluid. The injection of a magnetic field is responsible for compensating for the suction rate. An improvement in the concentration of nanoparticles and temperature is observed as a result of an increase in the slip rate. It is evident that both nanoparticle concentration and temperature rise significantly when Bi, the Biot number, is increased. In the boundary layer, a decrease in velocity is observed as a consequence of an increase in velocity slip, porosity, and magnetic field parameters.

Thermal radiation and heat source/sink influence on MHD heat transmission of copper (Cu)–aluminum oxide (Al2O3) Hybrid nanofluid flow with velocity and thermal slips along a stretching sheet

The primary aim of this study is to examine the Magneto radiative flow characteristics of Hybrid nanofluid, a subject of contention within the framework of a stretching sheet including porous material and a heat source/sink. The remarkable ability of hybrid nanoparticles to enhance heat transmission has fascinated several experts, prompting them to further investigate the properties of the working fluid. This work specifically examines the Hybrid Nanofluid flow with MHD and heat transfer on an elongating surface, taking into account radiation and chemical reaction. The study utilizes a mixture of copper ( Cu ) and aluminum oxide ( A l 2 O 3 ) nanoparticles combined with water ( H 2 O ) as the underlying fluid. The process of similarity conversion is used to translate the governing partial differential equations (PDEs) of the fluid flow model into nonlinear ordinary differential equations (ODEs). The whole set of non-linear coupled ODEs, together with the boundary circumstances, are numerically solved by means of the Keller-Box approach. Two unique fluids, known Cu/water (nanofluid) and as A l 2 O 3 − Cu / water (hybrid nanofluid), are used to investigate the flow factors affecting heat transportation phenomena. Comparing the numerical data with the findings reported in the prior works reveals a strong agreement. This research explores the impacts of convective heat transfer, thermal radiation, heat absorption, and MHD. Nanofluid technology has several technical and industrial uses, including power production, sun collecting, and heat exchangers for cooling. Although nanofluids have the highest heat transfer rate compared to traditional fluids, there are several limitations to their effectiveness.

A fully developed viscous electrically conducting fluid through infinitely parallel porous plates

AbstractThe current article deals with the steady behavior of a fully developed viscous electrically conducting and compressible Jeffrey fluid via infinitely parallel porous vertical microchannel in the sight of a transverse magnetic field. The fluid flow problem is modeled using Napier–Stokes and energy conservation equations. To analyze the problem, the leading equations are reformulated into dimensionless forms. These dimensionless transformed equations are described by nonlinear‐coupled ordinary differential equations and are eliminated utilizing the shooting method based on the fourth‐order Runge–Kutta technique through the boundary conditions; this represent slip velocity and temperature‐jump situations on the fluid–fence interface. The model equations are numerically solved with MATLAB's built‐in routine “bvp4c.” The behavior of Jeffrey fluid is described through graphs. The significance of model parameters is scrutinized and discussed in detail through graphs. Various significant impacts are examined in these simulations, such as radiation, magnetic field and viscous dissipation. Furthermore, the essential results of this investigation are the effects illustrated graphically and discussed quantitatively concerning various influencing parameters corresponding to the magnetic parameter, interaction parameter, buoyancy parameter, Darcy parameter, wall ambient temperature ratio, and the fluid‐wall relationship. We noticed that both walls are heated, that is, the velocity decreases with a rising Jeffrey parameter.

Geological fingerprints of deep slow earthquakes: A review of field constraints and directions for future research

Abstract Slow earthquakes, including low-frequency earthquakes, tremor, and geodetically detected slow-slip events, have been widely detected, most commonly at depths of 40–60 km in active subduction zones around the Pacific Ocean Basin. Rocks exhumed from these depths allow us to search for structures that may initiate slow earthquakes. The evidence for high pore-fluid pressures in subduction zones suggests that they may be associated with hydraulic fractures (e.g., veins) and with metamorphic reactions that release or consume water. Loss of continuity and resulting slip at rates exceeding 10−4 m s–1 are required to produce the quasi-seismic signature of low-frequency earthquakes, but the subseismic displacement rates require that the slip rate is slowed by a viscous process, such as low permeability, limiting the rate at which fluid can access a propagating fracture. Displacements during individual low-frequency earthquakes are unlikely to exceed 1 mm, but they need to be more than 0.1 mm and act over an area of ~105 m2 to produce a detectable effective seismic moment. This limits candidate structures to those that have lateral dimensions of ~300 m and move in increments of &amp;lt;1 mm. Possible candidates include arrays of sheeted shear veins showing crack-seal structures; dilational arcs in microfold hinges that form crenulation cleavages; brittle-ductile shear zones in which the viscous component of deformation can limit the displacement rate during slow-slip events; slip surfaces coated with materials, such as chlorite or serpentine, that exhibit a transition from velocity-weakening to velocity-strengthening behavior with increasing slip velocity; and block-in-matrix mélanges.

Statistical Analysis of Bubble Parameters from a Model Bubble Column with and without Counter-Current Flow

Bubble columns are widely used in numerous industrial processes because of their advantages in operation, design, and maintenance compared to other multiphase reactor types. In contrast to their simple design, the generated flow conditions inside a bubble column reactor are quite complex, especially in continuous mode with counter-current liquid flow. For the design and optimization of such reactors, precise numerical simulations and modelling are needed. These simulations and models have to be validated with experimental data. For this reason, experiments were carried out in a laboratory-scale bubble column using shadow imaging and particle image velocimetry (PIV) techniques with and without counter-current liquid flow. In the experiments, two types of gases—relatively poorly soluble air and well-soluble CO2—were used and the bubbles were generated with three different capillary diameters. With changing gas and liquid flow rates, overall, 108 different flow conditions were investigated. In addition to the liquid flow fields captured by PIV, shadow imaging data were also statistically evaluated in the measurement volume and bubble parameters such as bubble diameter, velocity, aspect ratio, bubble motion direction, and inclination. The bubble slip velocity was calculated from the measured liquid and bubble velocities. The analysis of these parameters shows that the counter-current liquid flow has a noticeable influence on the bubble parameters, especially on the bubble velocity and motion direction. In the case of CO2 bubbles, remarkable bubble shrinkage was observed with counter-current liquid flow due to the enhanced mass transfer. The results obtained for bubble aspect ratio are compared to known correlations from the literature. The comprehensive and extensive bubble data obtained in this study will now be used as a source for the development of correlations needed in the validation of numerical simulations and models. The data are available from the authors on request.