Conductivity Of Fluid Research Articles

Apparent Hysteresis in Archie’s Law: Implications of Changing Pore Fluid Conductivity for Electrical Resistivity Monitoring of Infiltration

The electrical resistivity of the vadose zone is highly dependent on soil moisture content (VWC), making ERT a potential tool for non-intrusive infiltration monitoring. There’s a long history of using Archie’s law to convert resistivity values to VWC, often under the assumption that the pore-fluid conductivity is constant. Analysis of two years of soil conductivity and VWC data from sensors buried in a bioswale in Philadelphia, Pennsylvania showed that the characteristic curve of VWC versus resistivity exhibited hysteresis. The same value of resistivity was associated with different VWC during imbibition and drying. Accurate VWC could be estimated using Archie’s law only after incorporating changes in pore-fluid conductivity. Additionally, pore-fluid conductivity varied seasonally, with the highest values recorded during winter from road salt runoff. Archie exponents differed for sensors within 25 cm of each other despite both the uniform nature of the bioswale soil and fits to Archie’s Law for individual sensors, indicating considerable heterogeneity. This pattern was confirmed at two additional sites. Assuming the conductivity of the pore-fluid remains constant during infiltration not only produces erroneous soil moisture estimates, it can even reverse the apparent soil moisture trend. We conclude that to use ERT to monitor infiltration it is essential to independently record changes in pore-fluid conductivity, and that multiple sensors are required because changes in pore-fluid conductivity and Archie parameters can vary on a sub-meter scale for even apparently homogeneous sites. Additionally, long-term changes in Archie parameters, notably m, are possible, and may indicate long-term changes in soil fabric.

Investigation of thermal conductivity and thermal performance of heat pipes by structurally designed copolymer stabilized ZnO nanofluid

The present study concentrated on estimating the thermal conductivity, stability, efficiency, and resistance of a heat pipe for heat exchangers, which were essential for many industrial applications. To achieve this, copolymer of amphiphilic poly (styrene-co-2-Acrylamido-2-methylpropane sulfonic acid) poly (STY-co-AMPS) was synthesized by free radical polymerisation technique. The dispersant were used for homogeneous solution and stabilization of ZnO nanofluids. The effect of dispersant on the thermal conductivity of nanofluids was analysed using a KD2 pro thermal property analyser. There is a significant increase in fluid conductivity had a nonlinear relationship with the volume fraction. The maximum enhancement was observed at an optimized concentration of dispersant at 1.5 vol%. Same time, the influence of dispersant agent on the thermal conductivity of nanofluids were compared with linear polyelectrolytes. Further, the experimental values were compared to the existing classical models based on the reasonable aggrement, the prepared nanofluids were employed as a working medium. The conventional screen mesh heat pipe and the temperature distribution to the thermal resistance of the heat pipe was investigated experimentally. The result shows, optimum concentration of dispersants on nanoparticles exhibits an enhanced heat efficiency as compared with the base fluids. Further, the thermal resistance and temperature distribution show decreased behaviour by increasing the particle volume fraction and dispersant concentration.

Analysis of coupled two-phase natural circulation loops by developing HEM and DFM based numerical models

The coupled two-phase natural circulation loop based passive systems find numerous applications, particularly in nuclear reactors where safety is paramount. However, the loops coupling, system conditions (specific to the reactor type), and inherent coupled loops feedback make their dynamics more complex. Hence, the models used should be capable of predicting such intricate coupled dynamics for precise forecasting of passive systems performance. With this objective, the present analyses deliberate the transients of such coupled two-phase loops linked to coupling configurations and operating conditions. Generalized two-phase models based on Homogeneous Equilibrium (HEM) and Drift Flux (DFM) with flashing, wall and fluid conduction, water-steam property formulation, etc., are developed and employed. Validation studies substantiate the prediction capability of these models for various cooler-heater orientations. Subsequently, predicted the start-up transients of vertically and horizontally coupled two-phase loops. The analyses revealed that coupling configurations, heater-cooler orientations and system conditions significantly influence the coupled loops. Further, the influences of various geometrical and operating parameters on the dynamics of coupled loops are investigated. It elucidated the differences in the parameter's effect on single-phase and two-phase coupled loops. The study also identified the vital parameters strongly influencing the coupled loops based on sensitivity analysis. The models and findings will be applied to evaluate the performance of coupled loop-based passive safety systems in nuclear reactors.

Electromagnetic prediction of rock thermal properties beyond boreholes: Soultz-sous-Forets (France) case study

Estimation of deep temperature, thermo-hydro-dynamic and basin simulation, heat exchange and geothermal resource assessment require knowledge of the rock thermal properties beyond boreholes. At the absence of suitable methods and instruments for such estimates we propose a new approach to prediction of thermal conductivity, specific heat capacity and heat flow density based on results of electromagnetic sounding of the study area. Artificial neural network used to this end is taught by correspondence between laboratory measurements on cores from the drilled boreholes and adjacent electrical conductivity profiles determined by inversion of the electromagnetic sounding data collected in their vicinity. This approach is used to estimate rock thermal properties along NW-SE magnetotelluric profile crossing Soultz-sous-Forêts geothermal area, Alsace, France. We demonstrate that accuracy of such prediction both in depths below the boreholes and in the interwell space is comparable with that usually achievable in the borehole scale. In particular, it is shown that relative errors of thermal conductivity prediction at depths twice as large as the borehole depth are as small as 2%, and the accuracy of cross-well thermal conductivity prediction is 6% and 10% for dry and wet rocks, respectively. On the other hand, the prediction accuracy for matrix thermal conductivity of a rock from the known profile of dry thermal conductivity is about 8%. Based on the results of our studies, we constructed dry and wet thermal conductivity sections from the electrical conductivity model determined earlier by 2-D inversion of magnetotelluric data. The temperature model of the study area built along the same profile by means of electromagnetic geothermometer and the obtained thermal conductivity sections enabled estimating the profiles of the vertical component of heat flow density at the surface from dry and wet thermal conductivity sections. They could be considered as minimum and maximum constraints, respectively, bounding the area of its possible values, which, in turn, depend on in situ thermal conductivity of fluids filling the rock pores. The range of possible vertical heat flow density variations (100–150 ± 10% mW·m− 2) agrees well with heat flow estimates in the Upper Rhine graben and, in particular, in Soultz-sous-Forêts geothermal area roughly estimated earlier from borehole measurements. Using the artificial neural network trained on the correspondence between the specific heat capacity determined in the borehole and adjacent electrical conductivity profile, we built the model of specific heat capacity. Against the background, a zone of enhanced specific heat capacity ranging between 2.05 and 2.15 MJ·m− 3·K− 1 was observed in the domain located at the base of the sedimentary cover and upper part of the granitic basement.

Detailing the pore structure of productive intervals within oil wells using 3D color imaging

The article describes an approach to the expansion of the methodology for applying hydraulic fracturing in oil fields by adding the possibilities of 3D modeling with color imaging of the pore structure within productive intervals of the wells. As an applied example, the geological and geophysical section of the productive level of one of the wells in Moscudinskoye oil field with known data on the integrated interpretation of the results of well logging and microcomputer tomography was chosen. According to well-logging data, the productive reservoir in the analyzed area of the section is characterized by a high degree of heterogeneity. The tomography studies of a full-size core enabled to identify four lithotypes here with different pore structure features. The consideration of the identified reservoir heterogeneity, as well as the data on the thickness and other characteristics of reservoir properties of individual lithotypes which make up the section, allowed to significantly increasing the detail of the final geological model of the wellbore section. A distinctive feature of this final geological model is the use of the method of enlargement of the initial data array by adding intermediate values which were calculated theoretically. The visibility of the final geological model of the borehole walls is provided by color 3D imaging of the calculated data of the enlarged massif and gives an idea on the presence of areas with good and weak fluid conductivity on the lateral surface of the borehole walls. According to this model, the intrastratal transverse and longitudinal fluid-conducting “corridors” are observed in the circumwell zone that define the hydro-dynamic movements of natural and artificial fluids in the medium of productive reservoirs.

Application of the Regular Mode Method to the Experimental Determination of Thermal Conductivity of Fluid

Application of the Regular Mode Method to the Experimental Determination of Thermal Conductivity of Fluid

Measurement of gas-liquid flows with the combination of thermal sensors and conductance sensor

Gas-liquid two-phase flow is a typical phenomenon in energy and industrial production. Thus, flow measurement of gas-liquid flow is vital in the exploration and extraction of oil and natural gas. The thermal sensors are based on convection heat transfer between heating elements and fluid. These sensors have been widely used in flow measurement because of their high precision, and low-pressure loss, and it is not affected by fluid conductivity and viscosity. This study utilized the thermal conductivity difference in liquid and gas to design a measurement system that combines thermal sensors and a conductance sensor. Among them, the thermal sensors contain 2 upstream and downstream thermal resistors and a total of 28 thermocouples distributed over 7 sections (4 for each section) to capture axial and sectional thermal information. A rotating electric field conductance sensor (REFCS) serves to accurately determine gas holdups. The model tests show that the separated flow models have better accuracy than the liquid-phase acceleration models and pressure drop models. Inspired by the classical separated flow models, an improved heat transfer model based on flow patterns is developed by adding an additional superficial velocity term. Based on the mechanism that the heat transfer is dominated by the liquid phase, the superficial velocities are measured in combination with the drift-flux model. Overall, the average absolute percentage deviations (AAPD) for both the heat transfer coefficients and superficial velocities are less than 5%, indicating that the improved model has excellent performance and robustness for flow prediction in 20 mm pipes.

Electrohydrodynamic Couette–Poiseuille Flow Instability of Two Viscous Conducting and Dielectric Fluid Layers Streaming through Brinkman Porous Medium

The electrohydrodynamic plane Couette–Poiseuille flow instability of two superposed conducting and dielectric viscous incompressible fluids confined between two rigid horizontal planes under the action of a normal electric field and pressure gradient through Brinkman porous medium has been analytically investigated. The lower plane is stationary, while the upper one is moving with constant velocity. The details of the base state mathematical model and the linearized model equations for the perturbed state are introduced. Following the usual procedure of linear stability analysis for viscous fluids, we derived two non-dimensional modified Orr–Sommerfeld equations and obtained the associated boundary and interfacial conditions suitable for the problem. The eigenvalue problem has been solved using asymptotic analysis for wave numbers in the long-wavelength limit to obtain a very complicated novel dispersion relation for the wave velocity through lengthy calculations. The obtained dispersion equation has been solved using Mathematica software v12.1 to study graphically the effects of various parameters on the stability of the system. It is obvious from the figures that the system in the absence of a porous medium and/or electric field is more unstable than in their presence. It is found also that the velocity of the upper rigid boundary, medium permeability, and Reynolds number have dual roles on the stability on the system, stabilizing as well as destabilizing depending on the viscosity ratio value. The electric potential, dielectric constant and pressure gradient are found to have destabilizing influences on the system, while the porosity of the porous medium, density ratio and Froude number have stabilizing influences. A depth ratio of less than one has a dual role on the stability of the system, while it has a stabilizing influence for values greater than one. It is observed that the viscosity stratification brings about a stabilizing as well as a destabilizing effect on the flow system.

Oscillatory Behavior of Heat Transfer and Magnetic Flux of Electrically Conductive Fluid Flow along Magnetized Cylinder with Variable Surface Temperature

The present study deals with electrically conductive fluid flow across a heated circular cylinder to examine the oscillatory magnetic flux and heat transfer in the presence of variable surface temperature. The proposed mathematical formulation is time-dependent, which is the source of the amplitude and fluctuation in this analysis. The designed fluctuating nonlinear computational model is associated with the differential equations under specific boundary conditions. The governing equations are converted into dimensionless form by using adequate dimensionless variables. To simplify the resolution of the set of governing equations, it is further reduced. The effects of surface temperature parameter β, magnetic force number ξ, buoyancy parameter λ, Prandtl number Pr, and magnetic Prandtl parameter γ are investigated. The main finding of the current study is related to the determination of the temperature distribution for each inclination angle. It is seen that a higher amplitude of the heat transfer rate occurs as the surface temperature increases. It is also noticed that the oscillatory magnetic flux becomes more important as the magnetic Prandtl number increases at each position. The present magneto-thermal analysis is significantly important in practical applications such as power plants, thermally insulated engines, and nuclear reactor cooling.

Magnetotelluric investigations at Andean volcanoes: Partial melt or saline magmatic fluids?

Knowledge of the architecture of active magmatic systems is important for both volcanic hazard assessment and evaluating potential geothermal energy production and metals recovery from magmatic fluids. Increasingly, magmatic systems are imaged using the magnetotelluric method to detect electrically conductive partial melt and/or saline magmatic fluid reservoirs. We review recent magnetotelluric studies at eight Andean volcanoes, revealing electrical conductivity anomalies with variable magnitudes and locations. Six of the studied volcanoes exhibit three main electrical conductivity anomalies, located at shallow (<3 km), intermediate (≈5 km), and deep (>10 km) depths. The shallow anomalies are often thin and laterally extensive, consistent with clay cap alteration layers, while the deep anomalies are generally interpreted as partial melt reservoirs. The intermediate depth anomalies, although also often attributed to partial melt, have less clear origins. By analysing laboratory-derived electrical conductivity relationships, we show that the intermediate depth anomalies are generally most consistent with saline magmatic fluids stored in porous rock. However, other geophysical and petrological data suggest that localised partial melt also exists at intermediate depths. Therefore, the intermediate depth anomalies likely represent mixed melt and saline magmatic fluid systems, such as those responsible for forming magmatic-hydrothermal alteration zones and copper porphyry deposits. At individual volcanoes, refining the generalised three layer model proposed here by using additional geophysical or petrological data is key to constraining the resources and/or hazard potential of the magmatic system.

Exploration of heat and mass transfer subjected to first order chemical reaction and thermal radiation: Comparative dynamics of nano, hybrid and tri-hybrid particles over dual stretching surface

This research is made to explore the combined influence of Soret and Dufour effect over dual stretchable porous surface considering the thermal radiation, mixed convection, and chemical reaction. Numerous researchers investigated that the thermal conductivity of host fluid increases from 10% to 40% when nanometer size particles are mixed in the host fluid. The augmentation of thermal conductivity of formed fluid depends upon numerous mechanisms of mixed nanoparticles like volume fraction and size of nanoparticles. So, in this research article, we considered three different types of nanoparticles to prepare the different nanofluids. The governing equations are converted through similarity transformation and numerically tackled in MATLAB via the boundary value problem algorithm. The numerical outcomes are validated with the published material. Graphs and tables are used to discuss the effects of various factors on momentum, energy, concentration, skin friction coefficient, and Nusselt and Sherwood's number. High heat and the mass transfer rate is perceived in the absence of rotation and porous medium parameter for all type of nanofluids. The skin friction increases along the x-axis and y-axis when the rotation of the fluid increases. Furthermore, a 33% improved heat transfer rate and reduced skin friction are noted for triple nanoparticle nanofluid which indicates its best performance as compared to both other nanofluids.

Gas hydrate saturation from NGHP 02 LWD data in the Mahanadi Basin

During the Indian National Gas Hydrate Program (NGHP) Expedition 02, Logging-while-drilling (LWD) logs were acquired at three sites (NGHP-02-11, NGHP-02-12, and NGHP-02-13) across the Mahanadi Basin in area A. We applied rock physics theory to available sonic velocity logs to know the distribution of gas hydrate at site NGHP-02-11 and NGHP-02-13. Rock physics modeling using sonic velocity at well location shows that gas hydrate is distributed mainly within the depth intervals of 150–265 m and 100–215 mbsf at site NGHP-02-11 and NGHP-02-13, respectively, with an average saturation of about 4% of the pore space and the maximum concentration of about 40% of the pore space at 250 m depth at site NGHP-02-11, and at site NGHP-02-13 an average saturation of about 2% of the pore space and the maximum concentration of about 20% of the pore space at 246 m depth, as gas hydrate is distributed mainly within 100–246 mbsf at this site. Saturation of gas hydrate estimated from the electrical resistivity method using density derived porosity and electrical resistivity logs from Archie's empirical formula shows high saturation compared to that from the sonic log. However, estimates of hydrate saturation based on sonic P-wave velocity may differ significantly from that based on resistivity, because gas and hydrate have higher resistivity than conductive pore fluid and sonic P-wave velocity shows strong effect on gas hydrate as a small amount of gas reduces the velocity significantly while increasing velocity due to the presence of hydrate. At site NGHP-02-11, gas hydrate saturation is in the range of 15%–30%, in two zones between 150-180 and 245–265 mbsf. Site NGHP-02-012 shows a gas hydrate saturation of 20%–30% in the zone between 100 and 207 mbsf. Site NGHP-02-13 shows a gas hydrate saturation up to 30% in the zone between 215 and 246 mbsf. Combined observations from rock physics modeling and Archie’s approximation show the gas hydrate concentrations are relatively low (<4% of the pore space) at the sites of the Mahanadi Basin in the turbidite channel system.

Numerical investigation of interactions between hydraulic and pre-existing opening-mode fractures in crystalline rocks based on a hydro-grain-based model

Hot dry rock (HDR) is deep geothermal reservoir rock predominantly containing granite, whose physical and mechanical properties are governed by heterogeneous crystal structures. However, the fluid conductivity of intact granite with ultra-low permeability cannot be reformed using existing techniques. Complex fracture networks must be created by connecting hydraulic fractures with natural fractures developed in reservoirs. In this study, we introduce the wall barrier method into the novel hydro-grain-based model (hydro-GBM) to build a prefractured granite model at the mineral grain scale. This model enables investigation of the effects of the stress environment, mineral spatial distribution, and fluid injection rate on hydraulic fracturing characteristics. Microcracks around the inner tips of pre-existing fractures reproduce the initiation, propagation, and coalescence behaviors similar to experimental results. Mineral spatial distributions induce random changes in the propagation paths of hydraulic fractures. Increasing the fluid injection rate delays the deflection of hydraulic fractures and extends the propagation distance along the major axes of pre-existing fractures. The average activity level and proportion of large seismic events are reduced by injecting low-rate fluid. In summary, our results reveal the interactions between hydraulic and pre-existing fractures and provide a valuable reference for constructing an efficient enhanced geothermal system (EGS) for deep reservoirs.

Synthesis, characterization, and application of Al2O3/coconut oil-based nanofluids in sustainable machining of AISI 1040 steel

The nanoparticles are suspended in a base fluid to create a colloidal suspension. They have great thermophysical and rheological qualities, making them a promising candidate for use in heat transfer applications. Nonetheless, vegetable oil has poor thermal and oxidative stability at higher temperatures, thus nano-additives are utilized to improve its cooling and lubricating properties. In this context, the thermophysical characteristics of nano-Al2O3 enriched coconut oil and their significant influence on the machinability of AISI-1040 steel have been investigated. The different %wt. concentrations (0.25% to 1.50%) of nano-Al2O3 are dispersed in coconut oil to analyse the wettability, dynamic viscosity, and thermal conductivity. Then, the turning experiments are carried out under dry, flood, MQL with pure coconut oil (MQL-CO), and nanofluid-MQL (NFMQL). The findings reveal that the incorporation of nanoparticles in coconut oil results in a reduction of up to 70% in the contact angle, indicating improved wettability. In addition, nanoparticle addition greatly improves the dynamic viscosity and thermal conductivity of the base fluid. NFMQL also greatly decreases tool wear and surface roughness in comparison to other cooling methods.

Acoustic radiation force on a spherical thermoviscous particle in a thermoviscous fluid including scattering and microstreaming.

We derive general analytical expressions for the time-averaged acoustic radiation force on a small spherical particle suspended in a fluid and located in an axisymmetric incident acoustic wave. We treat the cases of the particle being either an elastic solid or a fluid particle. The effects of particle vibrations, acoustic scattering, acoustic microstreaming, heat conduction, and temperature-dependent fluid viscosity are all included in the theory. Acoustic streaming inside the particle is also taken into account for the case of a fluid particle. No restrictions are placed on the widths of the viscous and thermal boundary layers relative to the particle radius. We compare the resulting acoustic radiation force with that obtained from previous theories in the literature, and we identify limits, where the theories agree, and specific cases of particle and fluid materials, where qualitative or significant quantitative deviations between the theories arise.

Gravitational versus Magnetohydrodynamic Waves in Curved Spacetime in the Presence of Large-Scale Magnetic Fields

The general-relativistic (GR) magnetohydrodynamic (MHD) equations for a conductive plasma fluid are derived and discussed in the curved spacetime described by Thorne’s metric tensor, i.e., a family of cosmological models with inherent anisotropy due to the existence of an ambient, large-scale magnetic field. In this framework, it is examined whether the magnetized plasma fluid that drives the evolution of such a model can be subsequently excited by a transient, plane-polarized gravitational wave (GW) or not. To do so, we consider the associated set of the perturbed equations of motion and integrate them numerically in order to study the evolution of instabilities triggered by the GW propagation. In particular, we examine to what extend perturbations of the electric and/or the magnetic field can be amplified due to a potential energy transfer from the GW to the electromagnetic (EM) degrees of freedom. The evolution of the perturbed quantities depends on four free parameters, namely, the conductivity of the fluid, σ; the speed of sound square, 13&lt;Csc2≡γ&lt;1, which in this model may serve also as a measure of the inherent anisotropy; the GW frequency, ωg; and the associated angle of propagation with respect to the direction of the magnetic field, θ. We find that GW propagation in the anisotropic magnetized medium under consideration does excite several MHD modes; in other words, there is energy transfer from the gravitational to the EM degrees of freedom that can result in the acceleration of charged particles at the spot and in the subsequent damping of the GW.

Drag reduction and optimization on a sphere with the effect of Lorentz force

The flow of a weakly conductive fluid (i.e. seawater) can be controlled by Lorentz force, which holds promising applications in drag reduction. In this paper, the drag reduction on a stationary sphere in the weakly conductive fluid with the Lorentz force on the sphere surface are numerically investigated at Re = 300. The relations among the vortex structures, the hydrodynamic forces, and the effects of drag reduction are discussed before and after the application of the Lorentz force. The results indicate that the fluid near the surface of the sphere is accelerated with the application of Lorentz force. Therefore, the flow separation on the rear surface of the sphere is suppressed, and the periodic shedding mode of hairpin vortices is replaced by the steady double-thread wake structure. Meanwhile, the increase of momentum near the sphere improves the capability to overcome the adverse pressure gradient. Therefore, the pressure on the leeward side of the sphere increases, and then the effect of drag reduction is achieved. Moreover, the effects of drag reduction are distinct with the different locations (θm) of the applied Lorentz force, which reaches the maximum drag reduction rate together with the maximum drag reduction efficiency for θm = 90°.

Synchronization and alignment of model oscillators based on Quincke rotation.

Colloidal spheres in weakly conductive fluids roll back and forth across the surface of a plane electrode when subject to strong electric fields. The so-called Quincke oscillators provide a basis for active matter based on self-oscillating units that can move, align, and synchronize within dynamic particle assemblies. Here, we develop a dynamical model for oscillations of a spherical particle and investigate the coupled dynamics of two such oscillators in the plane normal to the field. Building on existing descriptions of Quincke rotation, the model describes the dynamics of the charge, dipole, and quadrupole moments due to charge accumulation at the particle-fluid interface and particle rotation in the external field. The dynamics of the charge moments are coupled by the addition of a conductivity gradient, which describes asymmetries in the rates of charging near the electrode. We study the behavior of this model as a function of the field strength and gradient magnitude to identify the conditions required for sustained oscillations. We investigate the dynamics of two neighboring oscillators coupled by far field electric and hydrodynamic interactions in an unbounded fluid. Particles prefer to align and synchronize their rotary oscillations along the line of centers. The numerical results are reproduced and explained by accurate low-order approximations of the system dynamics based on weakly coupled oscillator theory. The coarse-grained dynamics of the oscillator phase and angle can be used to investigate collective behaviors within ensembles of many self-oscillating colloids.

Electric field and viscous fluid polarity effects on capillary-driven flow dynamics between parallel plates

—Micropumps have attracted considerable interest in micro-electro-mechanical systems (MEMS), microfluidic devices, and biomedical engineering to transfer fluids through capillaries. However, improving the sluggish capillary-driven flow of highly viscous fluids is critical for commercializing MEMS devices, particularly in underfill applications. This study investigated the behavior of different viscous fluid flows under the influence of capillary and electric potential effects. We observed that upon increasing the electric potential to 500 V, the underfill flow length of viscous fluids increased by 45% compared to their capillary flow length. To explore the dynamics of underfill flow under the influence of an electric potential, the polarity of highly viscous fluids was altered by adding NaCl. The results indicated an increase of 20–41% in the underfill flow length of highly viscous conductive fluids (0.5–4% NaCl additives in glycerol) at 500 V compared to that at 0 V. The underfill viscous fluid flow length improved under the electric potential effect owing to the polarity across the substance and increased permittivity of the fluid. A time-dependent simulation, which included a quasi-electrostatic module, level set module, and laminar two-phase flow, was executed using the COMSOL Multiphysics software to analyze the effect of the external electric field on the capillary-driven flow. The numerical simulation results agreed well with the experimental data, with an average deviation of 4–7% at various time steps for different viscous fluids. Our findings demonstrate the potential of utilizing electric fields to control the capillary-driven flow of highly viscous fluids in underfill applications.

Theoretical and simulation analysis of the measurement of polarized fluid flow in a circular pipe with electric field excitation

Measurement of conductive fluid flow velocity is essential in applications such as measuring the velocity of water flow in the agriculture sector, sewage water treatment plants, and metal refining industries. This paper proposes a contactless flow measurement device for computing the flow velocity of conductive fluids based on movement of polarized fluid flow. The proposed simulation model of the flow meter can also determine the conductivity of the fluid for varying flow velocity. The obtained simulated results concur with the earlier theoretical studies. Based on the interpretations in the underlying assumptions and physics of a fluid flow under a source of an electric field, it reveals that it is possible to measure a flow velocity of 0.01–10 m s−1 for conductive fluids of 0.1–10 S m−1.