Rheological Behavior Of Fluid Research Articles

Review of modeling schemes and machine learning algorithms for fluid rheological behavior analysis

Abstract Machine learning’s prowess in extracting insights from data has significantly advanced fluid rheological behavior prediction. This machine-learning-based approach, adaptable and precise, is effective when the strategy is appropriately selected. However, a comprehensive review of machine learning applications for predicting fluid rheology across various fields is rare. This article aims to identify and overview effective machine learning strategies for analyzing and predicting fluid rheology. Covering flow curve identification, yield stress characterization, and viscosity prediction, it compares machine learning techniques in these areas. The study finds common objectives across fluid models: flow curve correlation, rheological behavior dependency on variables, soft sensor applications, and spatial–temporal analysis. It is noted that models for one type can often adapt to similar behaviors in other fluids, especially in the first two categories. Simpler algorithms, such as feedforward neural networks and support vector regression, are usually sufficient for cases with narrow range variability and small datasets. Advanced methods, like hybrid approaches combining metaheuristic optimization with machine learning, are suitable for complex scenarios with multiple variables and large datasets. The article also proposes a reproducibility checklist, ensuring consistent research outcomes. This review serves as a guide for future exploration in machine learning for fluid rheology prediction.

Effect of 3-Carene and the Micellar Formulation on Leishmania (Leishmania) amazonensis.

Leishmaniases are neglected tropical diseases caused by obligate intracellular protozoa of the genus Leishmania. The drugs used in treatment have a high financial cost, a long treatment time, high toxicity, and variable efficacy. 3-Carene (3CR) is a hydrocarbon monoterpene that has shown in vitro activity against some Leishmania species; however, it has low water solubility and high volatility. This study aimed to develop Poloxamer 407 micelles capable of delivering 3CR (P407-3CR) to improve antileishmanial activity. The micelles formulated presented nanometric size, medium or low polydispersity, and Newtonian fluid rheological behavior. 3CR and P407-3CR inhibited the growth of L. (L.) amazonensis promastigote with IC50/48h of 488.1 ± 3.7 and 419.9 ±1.5 mM, respectively. Transmission electron microscopy analysis showed that 3CR induces multiple nuclei and kinetoplast phenotypes and the formation of numerous cytosolic invaginations. Additionally, the micelles were not cytotoxic to L929 cells or murine peritoneal macrophages, presenting activity on intracellular amastigotes. P407-3CR micelles (IC50/72 h = 0.7 ± 0.1 mM) increased the monoterpene activity by at least twice (3CR: IC50/72 h >1.5 mM). These results showed that P407 micelles are an effective nanosystem for delivering 3CR and potentiating antileishmanial activity. More studies are needed to evaluate this system as a potential therapeutic option for leishmaniases.

Nonsimilar stagnation flow of Williamson fluid over an isothermal linearly stretched sheet

The objective of this work is to analyze the boundary layer flow in the vicinity of a stagnation point on a linearly stretched isothermal flat surface. The ambient fluid temperature is considered different than that of the sheet. The streaming fluid rheological behavior is approximated via the Williamson fluid model. The normalized partial differential equations based on the balances of mass, momentum, and energy are simulated numerically via the symbolic and numeric computing software Maple for two entirely different scenarios. In the first scenario, the outer potential flow velocity dominates the sheet velocity whilst it is the other way round for the second scenario. The plots showing the behaviors of velocity and temperature are presented at various streamwise locations. The skin friction and Nusselt number are also visualized graphically and listed in tabular forms. The analysis reveals that all quantities including velocity and temperature show a strong dependence on the streamwise co-ordinate. In general, velocity distribution and temperature rise with a gradual march along the streamwise direction. The heat transfer coefficient also elevates upon an increase in the streamwise co-ordinate. This contradicts several previously published results on the boundary layer flow of Williamson fluid where no such dependence is seen.

Strong effect of fluid rheology on electrokinetic instability and subsequent mixing phenomena in a microfluidic T-junction

When two fluids of different electrical conductivities are transported under the influence of an electric field, the electrokinetic instability (EKI) phenomenon often triggers in a microfluidic device once the electric field strength and conductivity gradient exceed some critical values. This study presents a detailed numerical investigation of how the rheological behavior of a fluid obeyed by the non-Newtonian power-law constitutive relation could influence this EKI phenomenon in a microfluidic T-junction. We find that as the fluid rheological behavior changes from shear-thickening (n >1) to shear-thinning (n <1), the EKI phenomenon is significantly influenced under the same conditions. In particular, the intensity of this EKI phenomenon is found to be significantly higher in shear-thinning fluids than in Newtonian and shear-thickening fluids. Also, the critical value of the applied electric field strength for the inception of this EKI phenomenon gradually increases as the fluid rheological behavior progressively moves from shear-thinning to shear-thickening. The corresponding mixing phenomenon, often achieved using this EKI phenomenon, is also notably higher in shear-thinning fluids compared to Newtonian and shear-thickening fluids. A detailed analysis of both the flow dynamics and mixing phenomena inside the microdevice is presented and discussed in this study. To perform so, we also employ the data-driven dynamic mode decomposition technique, considered one of the widely used reduced-order models to analyze a dynamical system. This analysis facilitates a better understanding of the EKI-induced chaotic convection and mixing phenomena inside the microdevice. We observe that the spatial expanse and intensity of the coherent flow structures differ significantly as the power-law index changes, thereby providing valuable insight into certain aspects of the underlying flow dynamics that, otherwise, are not apparent from other analyses.

Oxidized cellulose nanofibers from sugarcane bagasse obtained by microfluidization: Morphology and rheological behavior

It is advantageous to understand the relationship between cellulose fiber morphology and the rheological behavior of its dispersions so that their application can be optimized. The goal of this study was to produce sugarcane bagasse-sourced cellulose dispersions with different numbers of high-pressure homogenization cycles. Microfluidization produced cellulose nanofibers (between 5 and 80 nm in diameter) with similar surface charge densities and crystallinities (measured on the resulting films). Oscillatory rheology showed that TEMPO-oxidized cellulose dispersions exhibited gel-like behavior. However, not only did the samples with more microfluidization cycles present a lower storage modulus, but the sample with 100 cycles completely lost the gel-like characteristic, presenting a viscous fluid rheological behavior. Thixotropy loop tests revealed the influence of nanofiber length on the dispersion's structure, as evidenced by the decrease in the hysteresis value along with fiber breakage. Therefore, our findings demonstrate that the rheological properties of the dispersion can be tuned according to the length of the nanofibers, allowing for targeted applications.

Buoyancy-Induced Instability of a Power-Law Fluid Saturating a Vertical Porous Slab

Abstract Many engineering applications involve porous media and rely on non-Newtonian working fluids. In this paper, the seepage flow of a non-Newtonian fluid saturating a vertical porous layer is studied. The buoyant flow is thermally driven by the boundaries of the porous layer, which are permeable surfaces kept at different temperatures. In order to model the seepage flow of both shear-thinning (pseudoplastic) and shear-thickening (dilatant) fluids, reference is made to the Ostwald-de Waele rheological model implemented via the power-law extended form of Darcy's law. The basic stationary flow is parallel to the vertical axis and shows a single-cell pattern, where the cell has infinite height and can display a core-region of enhanced/inhibited flow according to the fluid's rheological behavior. By applying small perturbations, a linear stability analysis of the basic flow is performed to determine the onset conditions for a multicellular pattern. This analysis is carried out numerically by employing the shooting method. The neutral stability curves and the values of the critical Rayleigh number are computed for different pseudoplastic and dilatant fluids. The behavior of a Newtonian fluid is also obtained as a limiting case.

Conjugated non-Newtonian phase change process in a shell and tube heat exchanger: A parametric-geometric analysis

The present study aims to better knowledge of the phase change process in shell and tube heat exchangers in the presence of thick tubes, porous medium, and Carreau- Yasuda non-Newtonian fluid. It is the first time that this combination has been presented in the literature. It is believed that considering the phase change process of RT-35 as a Carreau-Yasuda non-Newtonian one in the presence of porous medium and copper pipes can create a challenge in the field. The continuity and momentum equations along with the horizontal and vertical directions, the heat equation for RT-35 as a non-Newtonian Carreau–Yasuda fluid, and the heat equation for thick tubes were determined and transformed into their non-dimensional forms, which were then solved using the finite element method. The effects of non-dimensional numbers such as Stefan number, porosity parameter, Rayleigh number, and Effect of rheological behavior of fluid have been determined. Reaching better performance via using porous medium and center- a to- center distance of double pipes, as well as a number of the pipes, are the ideas to conduct the present study. The results were reported as the average Nusselt number, melting fraction of the PCM, the average velocity of the non-Newtonian fluid, streamlines, and isotherms, all as functions of non-dimensional time. The results indicated that higher values for the porosity parameter led to lower heat transfer rates, which in turn weakened the PCM melting front. It was also found that changing the center-to-center distance between the hot tubes influenced melting front propagation.

Rheological Behavior and Filtration of Water-Based Drilling Fluids Containing Graphene Oxide: Experimental Measurement, Mechanistic Understanding, and Modeling.

Any improvement in drilling technology is critical for developing the oil and gas industry. The success of drilling operations largely depends on drilling fluid characteristics. Drilling fluids require enough viscosity to suspend the particles and transport them to the surface and enough capability to control the fluid loss into the formation. Rheology and filtration characteristics of drilling fluids are crucial factors to consider while ensuring the effectiveness of a drilling operation. Graphene oxide (GO), xanthan gum (XG), and low-viscosity carboxymethyl cellulose (CMC LV) are being utilized in this research to produce high-performance, low-solid water-based drilling fluids (WDFs). Rheological and filtration behaviors of GO/XG/CMC LV-WDF were investigated as a function of GO, XG, and CMC LV at low concentrations (0.0–0.3% w/w) and atmospheric conditions. According to the findings, GO improved the rheological and filtration capabilities of the WDF. By adding 0.15 wt % GO, shear stress could be doubled, especially at a high shear rate of 1022 s–1. The plastic viscosity of the fluid could be expanded from 6 to 13 centipoise, and a fluid loss of 8.7 mL over 30 min was observed during the API fluid test, which would be lower than the suggested fluid loss value (15.0 mL) for water-based mud. At the same concentration of XG and CMC LV, XG had a more significant influence on rheological characteristics in the presence of GO. Adding 0.3 wt % XG could increase fluid shear stress from 20.21 to 30.21 Pa at a high shear rate of 1022 s–1. In contrast, CMC LV had more impact on filtration properties, acting as a filtration control agent by decreasing the API fluid loss of fluid from 21.4 to 14.2 mL over 30 min. The addition of XG and CMC LV to the GO solution may influence the microstructure of the filter cake, resulting in a tree-root morphology. Indeed, in the GO/CMC LV solution, the individual platelets may bind together, form a jellyfish shape, and block the micropores. The incorporation of CMC LV helped develop compact filter cakes, resulting in excellent filtration. Five rheological models were employed to match the fluid parameters quantitatively. The Herschel–Bulkley model outperformed the other models in simulating fluid rheological behavior. The findings of this study can be utilize to provide low-cost, stable, and environmentally compatible additives for drilling low-pressure, depleted, and fractured oil and gas reservoirs.

Exact solutions involving special functions for unsteady convective flow of magnetohydrodynamic second grade fluid with ramped conditions

A number of mathematical methods have been developed to determine the complex rheological behavior of fluid’s models. Such mathematical models are investigated using statistical, empirical, analytical, and iterative (numerical) methods. Due to this fact, this manuscript proposes an analytical analysis and comparison between Sumudu and Laplace transforms for the prediction of unsteady convective flow of magnetized second grade fluid. The mathematical model, say, unsteady convective flow of magnetized second grade fluid, is based on nonfractional approach consisting of ramped conditions. In order to investigate the heat transfer and velocity field profile, we invoked Sumudu and Laplace transforms for finding the hidden aspects of unsteady convective flow of magnetized second grade fluid. For the sake of the comparative analysis, the graphical illustration is depicted that reflects effective results for the first time in the open literature. In short, the obtained profiles of temperature and velocity fields with Laplace and Sumudu transforms are in good agreement on the basis of numerical simulations.

Experimental Investigation of the Rheological Behavior of an Oil-Based Drilling Fluid with Rheology Modifier and Oil Wetter Additives.

Drilling issues such as shale hydration, high-temperature tolerance, torque and drag are often resolved by applying an appropriate drilling fluid formulation. Oil-based drilling fluid (OBDF) formulations are usually composed of emulsifiers, lime, brine, viscosifier, fluid loss controller and weighting agent. These additives sometimes outperform in extended exposure to high pressure high temperature (HPHT) conditions encountered in deep wells, resulting in weighting material segregation, high fluid loss, poor rheology and poor emulsion stability. In this study, two additives, oil wetter and rheology modifier were incorporated into the OBDF and their performance was investigated by conducting rheology, fluid loss, zeta potential and emulsion stability tests before and after hot rolling at 16 h and 32 h. Extending the hot rolling period beyond what is commonly used in this type of experiment is necessary to ensure the fluid’s stability. It was found that HPHT hot rolling affected the properties of drilling fluids by decreasing the rheology parameters and emulsion stability with the increase in the hot rolling time to 32 h. Also, the fluid loss additive’s performance degraded as rolling temperature and time increased. Adding oil wetter and rheology modifier additives resulted in a slight loss of rheological profile after 32 h and maintained flat rheology profile. The emulsion stability was slightly decreased and stayed close to the recommended value (400 V). The fluid loss was controlled by optimizing the concentration of fluid loss additive and oil wetter. The presence of oil wetter improved the carrying capacity of drilling fluids and prevented the barite sag problem. The zeta potential test confirmed that the oil wetter converted the surface of barite from water to oil and improved its dispersion in the oil.

Double-diffusive mixed convection in rectangular cavities filled with non-Newtonian fluids

• Double-diffusive mixed convection in a double-lid driven rectangular cavity filled with non-Newtonian fluids is investigated analytically and numerically. • Analytical solution based on the parallel flow assumption agrees perfectly with the numerical solution for a wide range of governing parameters. • Mixed convection parameter is established to separate the dominance zones of natural, mixed and forced convective regimes for pseudo-plastic, Newtonian and dilatant fluids. • Increasing thermal Rayleigh number or Peclet number enhances fluid circulation and heat and mass transfer, by strengthening the buoyancy force and shear effect, respectively. • Increasing Lewis number/buoyancy ratio promotes the contribution of forced/natural regime. Also, forced convection affects strongly the rheological behavior of fluids as it abolishes its effect on flow characteristics observed in natural regime. The present study investigates numerically and analytically double-diffusive mixed convection in a closed rectangular cavity filled with non-Newtonian power-law fluid and subjected to uniform heat and mass fluxes from its vertical short sides, while the horizontal ones are insulated and impermeable and moving in opposite directions. The finite volume method is used to solve governing equations numerically, while the analytical solution is developed based on the parallel flow assumption valid in the case of a shallow cavity. A good agreement is found between both solutions for a wide range of governing parameters, namely, thermal Rayleigh number Ra T , Peclet number Pe , Lewis number Le , buoyancy ratio N , and power-law behavior index n . The effects of mentioned governing parameters on flow intensity and heat and mass transfer rates were illustrated and discussed in terms of the stream function Ψ, the average Nusselt number N u ¯ , the average Sherwood number S h ¯ , streamlines, isotherms, and iso-concentrations along with velocity, temperature, and concentration profiles. A mixed convection parameter is introduced to separate the zones where natural, mixed, and forced convective regimes dominate the convection, allowing to examine the effects of governing parameters for each separated regime. As a result, the ratios Ra T / Pe 2.6 , Ra T / Pe 3.0 and Ra T / Pe 3.4 are found to outline the limit between the predominance regions of the three convective regimes for n = 0.6, n = 1.0, and n = 1.4, respectively. It is found that increasing thermal Rayleigh number or Peclet number enhances heat and mass transfer, as the first strengthen the buoyancy force responsible for natural convection while the second promotes the contribution of shear effect accountable for forced convection. As for Le and N , interesting results are found, where increasing Le boost the contribution of forced convection while buoyancy ratio N produces an opposite effect, as increasing it leads to a more pronounced effect of natural regime on the convection. On the other hand, and while it is common knowledge that decreasing the power law-index enhances flow characteristics in the natural regime, the forced convection is found to affect strongly the rheological behavior of non-Newtonian fluids as it cancels the effect of n on flow characteristics.

Thermo-hydraulic and entropy generation analysis for non-Newtonian fluid flow through sinusoidal wavy wall channel

The present investigation deals with numerical simulation of thermo-hydraulic transport characteristics of non-Newtonian fluid flowing through a wavy channel subjected to isothermal condition. The power-law constitutive model is adopted to illustrate the rheological behavior of fluid. The influence of various parameters like index of power-law (n), Reynolds number (Re), amplitude of sinusoidal profile (A), etc. on flow, thermal field, and entropy generation characteristics are delineated in detail. Furthermore, the outcome of the sinusoidal channel is compared with that of conventional straight channel in order to check the performance of wavy-wall channels. Results divulge that reliance of the thermo-hydraulic characteristics on wall geometry is unequivocally affected due to the amplitude of sinusoidal profile. Augmentation in heat transfer rate for lower values of amplitude of sinusoidal profile over the conventional channel is inconsiderable although difference upraises considerably owing to two factors namely: higher amplitude of sinusoidal profile and Re. The heat transfer rate diminishes with increment in power-law index. Consequently, heat transfer rate is progressively conspicuous for shear thinning fluids compared to shear thickening fluids. For comparison of pressure drop in the wavy and equivalent straight channel taking into account heat transfer and corresponding enhancement of pressure drop, we have defined a performance parameter. The comparison of performance parameter illustrates that shear-thickening fluids are more appropriate for engineering applications. Two nondimensional numbers are defined to elucidate the behavior of entropy generation with various parameters like Reynolds number, amplitude of sinusoidal profile, and power-law index. The entropy generation increases as the amplitude of waviness increases. Furthermore, entropy generation also intensify with increment in index of power-law for a distinct Reynolds number and amplitude of waviness. Results obtained from present study can be used as a tool to select wall geometry for design of compact and economical energy exchange devices dealing with non-Newtonian power-law fluids.

Precise Method to Estimate the Herschel-Bulkley Parameters from Pipe Rheometer Measurements

Accurate characterization of the rheological behavior of non-Newtonian fluids is critical in a wide range of industries as it governs process efficiency, safety, and end-product quality. When the rheological behavior of fluid may vary substantially over a relatively short period of time, it is desirable to measure its viscous properties on a more continuous basis than relying on spot measurements made with a viscometer on a few samples. An attractive solution for inline rheological measurements is to measure pressure gradients while circulating fluid at different bulk velocities in a circular pipe. Yet, extracting the rheological model parameters may be challenging as measurement uncertainty may influence the precision of the model fitting. In this paper, we present a method to calibrate the Herschel-Bulkley rheological model to a series of differential pressure measurements made at variable bulk velocities using a combination of physics-based equations and nonlinear optimization. Experimental validation of the method is conducted on non-Newtonian shear-thinning fluid based on aqueous solutions of polymers and the results are compared to those obtained with a scientific rheometer. It is found that using a physics-based method to estimate the parameters contributes to reducing prediction errors, especially at low flow rates. With the tested polymeric fluid, the proportion difference between the estimated Herschel-Bulkley parameters and those obtained using the scientific rheometer are −24% for the yield stress, 0.26% for the consistency index, and 0.30% for the flow behavior index. Finally, the computation requires limited resources, and the algorithm can be implemented on low-power devices such as an embedded single-board computer or a mobile device.

Effects of surface modified nanosilica on drilling fluid and formation damage

Despite the fact that hydrophobic nanosilica can improve the stability of water/oil emulsion, there exist controversies pertaining to its influence on oil-based drilling fluid rheological behavior and the subsequent formation damage. The present study addresses the above using a surface modified nanosilica, where the particles were functionalized with different silane-based groups to alter their hydrophilicity: 3-glycidoxypropyl-triethoxy silane (GPTS) and combined GPTS and propyl silane (PGPTS). The NPs were characterized through FTIR analysis, particle size, and zeta-potential measurements followed by flow behavior experiments, core-scale mud flow tests, Computed Tomography (CT) scanning and SEM imaging techniques to determine the mud penetration depth.We found that, depending on the type of functionalized group and the size of NPs, the surface modification of NPs can enhance the rheological properties and mitigate formation-damage. The most desirable behavior, both in terms of the plastic viscosity and yield stress, was achieved with 15 nm size NPs. The functionalized NP with the 3-glycidoxypropyl-triethoxy silane (GPTS@SiO2), which is less hydrophilic compared with bare NP, improved plastic viscosity of the drilling fluid, however slightly deteriorated the yield stress. This was compensated for by adding a double amount of GPTS on the surface of NP (DGPTS@SiO2), which was shown to be more effective than merely increasing the GPTS content in the drilling fluid. Further improvement of rheological properties was made by combining GPTS and propyl silane (PGPTS@SiO2); implying the positive effect of reducing hydrophilicity on both the plastic viscosity and yield stress. It is noteworthy that surface modifications were identified to be efficient below an optimal concentration of 1 wt% of NPs due to the lack of particle agglomeration. Moreover, a decreasing trend in plastic viscosity was observed against increasing temperature as a result of lowering viscosity of the continuous phase. Meanwhile, the yield stress experienced greater changes versus temperature due to the larger dependency of the interactions between drilling fluids components on temperature.In addition, the results were further validated through a series of core-flow tests which showed that with the aid of the nano-based drilling fluids (NDFs) containing DGPTS@SiO2 and GPTS@SiO2 the penetration depth of mud, thus the degree of internal formation damage can be significantly reduced.

Evaluation of the settling behavior of hematite in an olefin-based drilling fluid using gamma-ray attenuation technique

As oil is the main component of the world's energy matrix, it has a strong influence on the dynamics of countries' economic and monetary systems. The drilling of an oil well is performed using specific drilling fluids, so that this process is as fast and safe as possible. Each region of the well requires a drilling fluid with particular characteristics. The rheological behavior of fluids affects both the cleaning process of wells, via transportation of cuttings to the surface, and the sedimentation of cuttings and particles present in the fluid formulation during drilling fluid flow interruptions due to corrective or preventive operating stops. Thus, this study aimed (i) to evaluate the rheological behavior of the additive hematite in olefin-based drilling fluids, (ii) to indirectly monitor the volumetric concentration variation of hematite particles during sedimentation using a non-destructive method called gamma-ray attenuation technique, and (iii) to determine constitutive equations for pressure on solids. The results showed that the addition of hematite in the olefin-based drilling fluid resulted in a non-Newtonian behavior, indicated by the behavior index of the power-law rheological model below 1. This behavior was accentuated by the increase in the proportion of hematite from 7.27 to 9.28%. Regarding the variation of volumetric concentration of solids in sedimentation, the increase in solids concentration retarded the settling process. In addition, the sediment formed presented a compressible behavior; therefore, the constitutive equations for pressure on solids presented a power index.

Thixotropy of sweetened condensed milk applied to flow fluid dynamics analysis of cylindrical pipes

AbstractUnderstanding the rheological behavior of fluids and the parameters related to flow fluid dynamics is important for better designing equipment and enhancing processes in the food industry. Thus, the objective of this study was to characterize the rheological behavior of sweetened condensed milk (SCM) in the temperature range of 278.15 to 343.15 K, investigate the friction factor in laminar flow for this fluid, and evaluate the correlation between the rheological behavior obtained from fluid dynamics data and that obtained from rheological assays. The rheological properties of the SCM were determined in triplicate using an AR 2000 controlled tension rotational rheometer with a parallel‐plate and cone‐and‐plate geometry and the pressure drop measurement system consisting of stainless steel pipes connected to a 0.1 m3 stainless steel cylindrical tank. Pseudoplastic behavior with thixotropy was observed, and the friction factor in laminar flow diverged from the theoretical value, with a maximum relative deviation of 42.4% for the data in the descending curve. The maximum relative deviation between the calculated pressure drop and the experimental values was 36.8%. A satisfactory correlation was obtained between the SCM rheological behaviors obtained using rheometer data and pressure drop assays.Practical ApplicationsSweetened condensed milk is one of the main products used in the production of sweets and desserts. Its production involves unity operations, for example, pumping and heat treatments. Correctly designing the equipment used in these operations, as well as enhancing the processing parameters, requires the understanding of fluid rheological behavior, specifically the changes induced when shear rates are applied to the fluid. In the present study, the correlation between the rheology of SCM indicated by fluid dynamics data obtained using a pipe and pumping system and the rheological parameters obtained via rheological tests using a rheometer was investigated to evaluate the behavior of this fluid during its flowing.

MHD Effects on Ciliary-Induced Peristaltic Flow Coatings with Rheological Hybrid Nanofluid

Present theoretical investigation is a mathematical illustration of an application to endoscopy by incorporating hybrid nanoparticles and an induced magnetic field with a rheological fluid model for more realistic results. Rheological fluid behavior is characterized by the Ostwald-de-Waele power-law model. A hybrid nanofluid mechanism is considered comprising platelet-shaped nanoparticles since nanoparticles are potential drug transportation tools in biomedical applications. Moreover, ciliary activity is encountered regarding their extensive applications in performing complex functions along with buoyancy effects. An endoscope is inserted inside a ciliated tube and peristalsis occurred due to ciliary activity in the gap between tube and endoscope. A non-Newtonian model is developed by mathematical formulation which is tackled analytically using homotopy analysis. The outcomes are interpreted graphically along with the pressure rise and streamlining configuration for the case of negligible inertial forces and long wavelength. A three-dimensional graphical interpretation of axial velocity is studied as well. Moreover, tables are prepared and displayed for a more physical insight.

Measurement and modelling for harmonic dynamic characteristics of a liquid-filled isolator with a rubber element and high-viscosity silicone oil at low frequency

Key dynamic characteristics of a novel liquid-filled isolator with an annular orifice are investigated at low frequency by using experimental and analytical methods, both within the context of a simplified suspended cab model. The isolator is proposed to be characterized by a coupled parallel combination of a rubber path and a liquid path, through which motions or forces are transmitted to a resonant receiver, commonly an earthmoving machinery cab. To appropriately examine isolator dynamic properties, experimental results are compared with those of the corresponding rubber isolator while dynamic excitations under frequency-sweep and fixed-frequency are applied, respectively. It is observed that the liquid-filled isolator provides more desired dynamic performance for resonance mitigation and vibration isolation. It is suggested that an amplitude-dependent, softening nonlinearity presented in the dynamic stiffness should mainly result from the viscoelastic behavior of the silicone oil and also relate closely to the coupling properties. Also, small jerks in the acceleration response involved with asymmetric damping characteristics are present by a shock excitation, while almost no asymmetric characteristics are revealed under harmonic excitations although the isolator internal construction is asymmetric. Two models are developed by using Navier-Stokes equations, incorporating fluid rheological behavior and compressibility. Simulated and measured force-displacement loops are compared to indicate the models’ validity. Accordingly, a lumped model (Model 3) consisting of cubic elastic force and fractional-power damping force terms is proposed, yielding a better prediction. The studies in this paper suggest key design parameters and form an essential first step for design optimization.

Screening Study on Rheological Behavior and Phase Transition Point of Polymer-containing Fluids produced under the Oil Freezing Point Temperature

AbstractFor an increasing implementation of the low-temperature transportation in oilfield, it is urgent priority initially to study the physical and chemical properties to provide the vital technical support for the low-temperature transport of the polymer flooding. In this paper, the rheological behavior of polymer-containing fluid produced from the Daqing polymer flood were first studied for an adaptation of transportation under the oil’s freezing point temperature. The experiments progressed with different temperature, shear rate, water content and polymer concentration which have great impacts on the viscosity of the fluids produced aiming to find the phase transportation point for the application of the low-temperature transportation. It was displayed that a significant discontinuity in the viscosity occurs at some range of water content. Before the phase transition point, presented in W/O (water-in-oil) emulsion, the viscosity was lifted with the increase of the water content while after the phase transition point, forming the O/W (oil-in-water) type emulsion, the viscosity was dropped with an increase of water content. The phase transition points strongly depend on the polymer concentration in the fluids Produced. It was demonstrated that the phase transition points of polymer-containing fluids were 65%, 70%, 50%, 50% and 50%, corresponding to the polymer concentrations of 315mg/L, 503mg/L, 708mg/L, 920mg/L and 1053mg/L, respectively. The characteristics are attributed to the viscous polymer. The fluidity of the fluid produced was decreased with the increase of polymer concentration.

Influence of Degree of Dispersion of Noncovalent Functionalized Graphene Nanoplatelets on Rheological Behaviour of Aqueous Drilling Fluids

Application of carbon nanomaterials in oil well drilling fluid has been previously studied and was found to enhance its filtration properties. There is a general consensus that addition of colloids in suspension will alter its rheology, i.e., carbon nanomaterials, in this research work; graphene nanoplatelets are hydrophobic materials, which require functionalisation to improve its dispersion in aqueous solution. However, different degrees of dispersion may vary the rheological properties behaviour of drilling fluid. The objective of this study was to characterize the colloidal dispersion of graphene nanoplatelets (GNP) in aqueous solution and its impact on the rheological properties behaviour of water-based drilling fluid. Dispersion of graphene nanoplatelets was achieved through noncovalent functionalisation by means of surfactant attachment. UV-visible spectroscopy was employed to analyze the dispersion of GNP in aqueous solution. The rheological test was carried out using a simple direct-indicating viscometer at six different speeds. Results revealed that the degree of dispersion of GNP using Triton X-100 was generally higher than both SDS and DTAB. Comparison between the rheological properties behaviour of drilling fluid with GNP dispersed using different surfactants shows little to no difference at low shear rates. At high shear rates, however, greater dispersion of GNP shows higher thinning properties while fluid with a low dispersion of GNP exhibited linear behaviour to thickening properties.