Bingham Model Research Articles

Study on the Influence of Temperature–Magnetic Field Coupling on the Mechanical Properties of Magnetorheological Fluids

The composition of a magnetorheological fluid (MRF) usually includes magnetic particles, a carrier fluid, and additives. Among them, the magnetic particles and carrier fluid are the main sources of the mechanical properties of the MRF. The changes of the related properties of the two will affect the mechanical properties of the MRF directly or indirectly. Herein, first, the temperature–magnetic field characteristics are analyzed during the MRF working process. Then, the influence mechanism of temperature and magnetic field changes on the properties of the magnetic particles and carrier liquid are analyzed. On this basis, the traditional Bingham model is improved and optimized, in which the temperature variable is introduced to represent the effect of temperature–magnetic field coupling on the shear stress of the MRF. Finally, parameter fitting and simulation are carried out for the optimized model, and the self‐made shear stress of the MRF measuring device with temperature‐control function is used to experimentally verify the accuracy of the optimized model. The comparison and verification of the results show that the optimized model can better represent the variation of shear stress of an MRF with temperature and magnetic field than the traditional Bingham model.

Channel flows of shear-thinning fluids that mimic the mechanical response of a Bingham fluid

The linear stability of channel flows driven by pressure drops is carried out for fluids that exhibit a yield stress, the mechanical response of which is prescribed by the Bingham constitutive relation or two of its regularizations: the model due to Allouche and co-workers that is usually referred to as the “simple model”, and Papanastasiou model. Despite the fact that these two regularized models provide a good approximation of the steady Poiseuille flow of a Bingham fluid, they fail to predict the stability characteristics of the exact Bingham model. The critical thresholds for the onset of turbulence predicted by using the simple and Papanastasiou models are essentially the same, but they differ significantly from that of the exact Bingham model. This discrepancy is shown to be due to the absence of energy dissipation in the rigid core of a Bingham fluid.

Concrete Shear Box: New Instrument to Assess Stiff to Flowing Concrete Using Bingham Model

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Numerical modeling of an elasto-viscoplastic fluid around a plate perpendicular to the flow direction

• A new EVP constitutive equation coupling the bingham and maxwell models is presented. • Computations have been performed using the FEMLIP method. • Elasticity and plasticity have an influence on flow morphology. • The fore-aft asymmetry is due to elasticity. • Elastic effects decrease as plastic effects become stronger. This numerical study investigates the creeping flow of an elasto-viscoplastic fluid around a plate perpendicular to the flow direction. The analysis is performed with the Finite Element Method with Lagrangian Integration Points (FEMLIP). This numerical method is able to simulate large deformations problems and to describe yielded and unyielded regions by precisely accounting for elastic stresses. An elasto-viscoplastic model coupling the Bingham and the Maxwell constitutive equations is used. The influences of plasticity and elasticity on kinematic and stress fields are discussed. The influence of elasticity on the fore-aft asymmetry of the flow morphology is shown and quantified. The size and shape of the yielded and unyielded regions around the obstacle are also quantified. Finally, far and local stress fields as well as the drag coefficient are quantified as a function of the plastic and elastic contributions.

Lagrangian Differencing Dynamics for Time-Independent Non-Newtonian Materials.

This paper introduces a novel meshless and Lagrangian approach for simulating non-Newtonian flows, named Lagrangian Differencing Dynamics (LDD). Second-order-consistent spatial operators are used to directly discretize and solve generalized Navier–Stokes equations in a strong formulation. The solution is obtained using a split-step scheme, i.e., by decoupling the solutions of the pressure and velocity. The pressure is obtained by solving a Poisson equation, and the velocity is solved in a semi-implicit formulation. The matrix-free solution to the equations, and Lagrangian advection of mesh-free nodes allowed for a fully parallelized implementation on the CPU and GPU, which ensured an affordable computing time and large time steps. A set of four benchmarks are presented to demonstrate the robustness and accuracy of the proposed formulation. The tested two- and three-dimensional simulations used Power Law, Casson and Bingham models. An Abram slump test and a dam break test were performed using the Bingham model, yielding visual and numerical results in accordance with the experimental data. A square lid-driven cavity was tested using the Casson model, while the Power Law model was used for a skewed lid-driven cavity test. The simulation results of the lid-driven cavity tests are in good agreement with velocity profiles and stream lines of published reports. A fully implicit scheme will be introduced in future work. As the method precisely reproduces the pressure field, non-Newtonian models that strongly depend on the pressure will be validated.

DETERMINATION OF FLOW AND VISCOELASTIC PROPERTIES OF THE KYRGYZ ETHNIC FOOD “SÜZMÖ” DEPENDING ON TEMPERATURE AND MOISTURE CONTENT

Consumer interest in concentrated protein-rich food is growing. Kyrgyz traditional food Süzmö, which is a highly viscous dairy product that is produced from fermented milk Ayran, needs to be introduced into the dairy industry. In this study, the rheological parameters of this indigenous food product were investigated in steady and dynamic rheological experiments. The flow behaviours of Süzmö were evaluated at six temperatures (20, 30, 40, 50, 60, and 70°C) and suitable rheological models were found. The flow curves of Süzmö at investigated temperatures have the yield stress (τ0) values between 32.64 Pa and 285.87 Pa. The flow properties of Süzmö samples at 20 and 30°C correspond to the Bingham model. The Casson model was suitable for describing flow curves at 40, 50, 60, and 70°C with correlation coefficients R=0.9506 ‒ 0.9973. The effective viscosity (ƞeff) of Süzmö decreased from 15.88 to 0.26 Pa·s with increasing temperature from 20 and 70°C. The effect of temperature on the viscosity corresponds to the Arrhenius relationship. The calculated activation energy was 61.66 kJ/(mol). A linear model was defined taking into account the influence of moisture content (p>0.05) on effective viscosity (ƞeff) and yield stress (τ0). A temperature-sweep was performed at 20 to 80°C to determine the thermal denaturation of the fermented milk samples. The measured parameters are essential for the industrial production of Süzmö and other concentrated fermented milk products.

Review of rheological behaviour of sewage sludge and its importance in the management of wastewater treatment plants

Abstract The process operation of wastewater treatment plants (WWTPs) is based on the proper set up of several physical, chemical and biological parameters. Often, issues and problems arising in the process are strictly linked to the rheological behaviour of sewage sludge (SeS). Therefore, rheological measurements, which recently have captured a growing interest, represent an important aspect to consider in the design and operation of WWTPs, especially in the sludge-handling processes. The knowledge of rheological behaviour of SeS represents a crucial step to better understand its flow behaviour and therefore optimize the performance of the processes, minimizing the costs. The SeS are non-Newtonian fluids and, to date, Bingham and Ostwald models are the most applied. This work presents an overview of scientific literature about the rheological properties of SeS and discusses the importance of its knowledge for the management of WWTPs.

Review of Magnetorheological Damping Systems on a Seismic Building

Building structures are vulnerable to the shocks caused by earthquakes. Buildings that have been destroyed by an earthquake are very detrimental in terms of material loss and mental trauma. However, technological developments now enable us to anticipate shocks from earthquakes and minimize losses. One of the technologies that has been used, and is currently being further developed, is a damping device that is fitted to the building structure. There are various types of damping devices, each with different characteristics and systems. Multiple studies on damping devices have resulted in the development of various types, such as friction dampers (FDs), tuned mass dampers (TMDs), and viscous dampers (VDs). However, studies on attenuation devices are mostly based on the type of system and can be divided into three categories, namely passive, active, and semi-active. As such, each type and system have their own advantages and disadvantages. This study investigated the efficacy of a magnetorheological (MR) damper, a viscous-type damping device with a semi-active system, in a simulation that applied the damper to the side of a building structure. Although MR dampers have been extensively used and developed as inter-story damping devices, very few studies have analyzed their models and controls even though both are equally important in controlled dampers for semi-active systems. Of the various types of models, the Bingham model is the most popular as indicated by the large number of publications available on the subject. Most models adapt the Bingham model because it is the most straightforward of all the models. Fuzzy controls are often used for MR dampers in both simulations and experiments. This review provides benefits for further investigation of building damping devices, especially semi-active damping devices that use magnetorheological fluids as working fluids. In particular, this paper provides fundamental material on modeling and control systems used in magnetorheological dampers for buildings. In fact, magnetorheological dampers are no less attractive than other damping devices, such as tuned mass dampers and other viscous dampers. Their reliability is related to the damping control, which could be turned into an interesting discussion for further investigation.

Influence of magnetorheological lubricant behavior on the performance of annular recessed orifice compensated non-textured/textured thrust pad bearing

Fluid film bearings operated with smart lubricants have been successfully used to enhance the lubricating performance. This article proposes a computational model to analyze the influence of magnetorheological lubricant on the performance of an annular recessed hybrid thrust bearing system. The governing modified Reynolds equation for circular thrust pad orifice compensated bearing is solved by finite element method. Further, for simulating the flow behavior of magnetorheological lubricant, a constitutive relation for the Bingham model Dave equation, has been used. The numerical results reveal that using magnetorheological lubricant improves the loading carrying capacity and damping coefficient of both annular and circular recess hybrid thrust bearings. Additionally, bearing lubricated with magnetorheological lubricant requires a lesser quantity of flow and hence less pumping power.

Effect of Waste Glass on Slurry Rheological Properties of Cement and Concrete

In order to realize the recycling of waste glass, the influence of waste glass on the rheological properties of cement paste and concrete was studied. The rheological parameters were obtained by linear fitting with Bingham model. The results showed that for cement slurry system, with the replacement amount of waste glass increasing from 0 wt% to 20 wt%, the plastic viscosity of slurry increased gradually, while the yield stress decreased. Fixing the replacement amount of fixed waste glass at 5 wt%, the plastic viscosity and yield stress of cement slurry decrease with the increasing dosage of polycarboxylate superplasticizer. The cement slurry conforms to the characteristics of pseudoplastic fluid. For initial concrete slurry system, with the increase of waste glass replacement amount from 0 wt% to 20 wt%, the plastic viscosity of slurry increased, while the yield stress gradually decreased. And then the rheological properties of concrete slurry were closed to Newtonian fluid. After 1 hour, the plastic viscosity of concrete increased first, then decreased, and finally increased again. The yield stress decreased gradually. And the rheological properties of slurry were also close to Newtonian fluid.

Rheology, early-age hydration and microstructure of alkali-activated GGBFS-Fly ash-limestone mixtures

In this study, the effects of limestone powder on the rheological behavior, pore solution chemistry, mechanical properties and microstructure of alkali-activated cements have been investigated. The results exhibit that, with the increasing content of limestone powder in the ternary alkali-activated system, the structural build-up of the mixture increases earlier. It was observed that flow curves of pastes fit the Bingham model well. With the increasing content of fly ash in the ternary mixtures, the plastic viscosity decreased as expected by the particle packing effect and the increased water film thickness as well as the spherical shape of fly ash particles. As a result of the higher specific surface and improved nucleation provided by the limestone powder, the reaction process was enhanced and accelerated for the mixtures with higher limestone powder contents. The calcium and alumina concentrations in the pore solution rapidly evolved at first for a certain time, but decreased afterwards. The significant influence of the Ms value of the activator was observed on the evolution of the elemental concentrations. Microstructure analysis revealed that the early age reaction product is C-A-S-H for the slag mixtures incorporating limestone or fly ash. The compressive strength of the ternary mixtures decreased with the incorporation of limestone powder due to the inert character of the limestone powder.

Elastic-Viscoplastic Constitutive Model of Soil under Cyclic Loading

The creep problems are often involved in soil under cyclic loading, and its behaviors of soil under cyclic loading sparks many arguments in current research field. To propose one new model to demonstrate these creep behaviors of soil under cyclic loading, the cyclic loading was simplified equivalently, and the elastic-viscoplastic model (EVPM) for soil under cyclic loading was established based on the Bingham model. The yield criterion for soil under cyclic loading with constant amplitude was proposed following the simplified load. A constitutive equation based on the EVPM was constructed by using the flow criterion related to the yield criterion. Meanwhile, the parameters of EVPM were identified and discussed. In addition, the case analysis of the EVPM was also performed. The results indicate that the stable and destructive creep behaviors of soil under cyclic loading could be well described by the recommended EVPM, and the obtained parameters in the model exhibited a clear regularity with the increase of dynamic stress amplitude. Besides, the established model could be selected to predict the stable and destructive creep behavior of soil under cyclic loading.

Test protocol and rheological model influence on determining the rheological properties of cement pastes

The rheological characterization of cement pastes, mortars and concretes considers the rheological parameters of complex suspensions, composed by different materials, which interact both chemically, and physically. In addition, distinct test conditions and diverse mixture compositions may also interfere on determining the composites’ rheological properties. Along these lines, this work evaluates the test protocol and the rheological model influence on the rheological characterization of cement pastes. To do so, we established four different test protocols, with two maximum shear rates (50 and 100 s−1) and two distinct shearing methods (single-staged and multiple-staged). Bigham, modified Bingham and Herschel-Bulkley models were used to fit the experimental data. The water/cement mass ratio of the studied pastes ranged between 0.40 and 0.65. Our analysis indicates that the test protocol and the rheological model exerts significant influence on determining rheological parameters. In general, Herschel-Bulkley model showed better fitting to experimental data. More reproductive results were verified on the multiple-staged shearing with a maximum shear rate of 100 s−1.

Introducing a Rheology Model for Non-Newtonian Drilling Fluids

An API standard drilling fluid was investigated from laminar to turbulent flow conditions using an in-house-built viscometer at speeds from 200 to 1600 RPM. A power-based method was applied to obtain the apparent viscosity and the shear stress of the water-based drilling mud (WBM) in the annulus of the viscometer. Then, a MATLAB optimization program was developed to obtain model parameters for five rheology models integrated in a generalized Herschel-Bulkley-Extended (HBE) model and two widely used 4-parameter models in drilling industry. It is found that the Bingham, Cross, and HBE rheology models have precisely matched the WBM measurements in the viscometer. A generalized Reynolds number was applied to determine the Darcy friction factor although the PL (power law model) and the HB (Herschel-Bulkley model) exhibited a nonrealistic negative shift from the laminar friction factor.

Rheological behavior of concentrated peach puree and its dilutions in a stationary state / Comportamento reológico em estado estacionário de purê de pêssego concentrado e suas diluições

A rheometer equipped with a concentric cylinder system, was used to study the effects of temperature (15, 25, 40, 55 and 70°C) and concentration (10, 12, 15, 20, 25 and 30.5ºBrix) on the flow behavior of peach puree. The rheograms were analyzed by the Power law, Herschel-Bulkley, Bingham and Casson models. The different sample concentrations were prepared as from a concentrated peach puree at 30.5ºBrix, with absolute density of 1077.49kg/m 3 , pulp content of 60.90% and pH value of 3.51. All the puree concentrations showed pseudoplastic behavior at all the temperatures with yield stress, and the Herschel-Bulkley model adequately described the flow behavior. The temperature dependence was well described by the Arrhenius model. The flow activation energy (Ea) of the concentrated peach puree (30.5ºBrix) was 5.556kJ.mol -1 and increased with reduction in the soluble solids concentration. The exponential model was adequate to describe the effect of the puree concentration on the apparent viscosity () and on the consistency index (K). Physicochemical characterization and rheological parameters are used by the food industry to optimize the development of processes, equipment and quality control procedures for the production of pulps, nectars and fruit juices.

A nomogram for cement-based rock grouting

The assumption of cement grouts as ‘Bingham fluids’ has thus far facilitated the development of simplified analytical tools for rock grouting design. However, from a practical standpoint the use of the Bingham constitutive law throughout the design phase has several shortcomings that merit being more systematically addressed. For instance, the known key attributes of cementitious suspensions, e.g. wall-slip, thixotropy, shear rate and time dependency that influence the grout propagation especially at low shear rates are not considered when the Bingham model is used. As such, the consequences of overlooking such crucial phenomena whilst aiming for simplicity in design remain relatively unknown. In this work, we show how considering the shear rate aspects and stop criteria with the Bingham model can be better used for grouting design. Our design suggestions are based on fundamental analysis and theory of Bingham fluid radial flow and current knowledge on cement grout rheological behaviour, as reported from rheological experiments. Moreover, we contribute to the existing design procedure by presenting a nomogram that can readily be used for practical rock grouting design. The nomogram approach allows rapid computation of all key parameters, which in essence shows that unless wall slip is taken into account up to ~50% overestimation of grout travel results.

COMBINED CONTROL OF VEHICLE SUSPENSION WITH FRACTIONAL-ORDER MAGNETORHEOLOGICAL FLUID DAMPER MODEL

The fractional-order Bingham model of magnetorheological fluid damper has simple structure and can better describe the hysteretic characteristics of the system. The vibration control of a nonlinear vehicle suspension system with magnetorheological fluid damper under harmonic excitation is studied, where the single-degree-of-freedom 1/4 vehicle suspension system with fractional-order Bingham model of magnetorheological fluid damper is considered. The primary resonance response of suspension system with fractional-order Bingham model under sky-hook damping semi-active control is analyzed, and the approximate analytical solution is obtained by means of averaging method. The amplitude-frequency response equation of the steady-state solution of the suspension system is obtained, and the stability condition of the suspension system is also obtained according to Lyapunov’s stability theory. By comparing the amplitude-frequency response curves of the numerical solution and approximate analytical solution, the accuracy of the approximate analytical solution has been verified. The influence of semi-active control on the ride comfort of the vehicle is illustrated by the root mean square values of acceleration of the sprung mass in the vertical direction, it is found that the semi-active control strategy of sky-hook damping can not improve the ride comfort of vehicle in low frequency excitation region of road. Therefore, a combined control strategy of passive control and semi-active control is proposed, and the influence of semi-active control parameter on the vibration control effect is analyzed. The results show that the combined control strategy can not only improve the ride comfort of the vehicle, but also effectively suppress the primary resonance vibration amplitude of suspension system.

Method for calculating dynamic yield stress of fresh cement pastes using a coaxial cylinder system

AbstractThe calculation of the rheological parameters of fresh cement pastes plays a key role in understanding the rheology of cement‐based mixes. Because cement paste is not a simple Bingham fluid, a suitable nonlinear model must be found for characterizing its flow. A test system in which the rotational speed or shear rate can be changed in multiple steps is regarded as a suitable rheological test protocol because the paste reaches a steady state. Furthermore, theoretical derivations show that the solution of the Couette inverse problem corresponding to the modified Bingham model and the Herschel–Bulkley (H‐B) model is complex. However, a comparative analysis revealed that the yield stress of fresh paste could easily be obtained through a calculation process based on a Parabolic model. This study presents the complete calculation procedure for this model. The influence of the plug flow is considered, and test points with low minimum shear stress (τmin) are excluded. Finally, the accuracy of the proposed method is verified through comparisons with the results obtained using mini‐cone slump tests. These results show that the dynamic yield stress calculated using the expression of the Couette inverse problem based on the Parabolic model in consideration of the plug flow is very close to the yield stress obtained using the mini‐cone slump flow test. This proves that the proposed method could precisely characterize the dynamic yield stress of cement pastes.

Rheological Properties of Ultra-Fine Tailings Cemented Paste Backfill under Ultrasonic Wave Action

Ultra-fine tailings cemented paste backfill (UCPB) exhibits special rheological characteristics with the effect of an ultrasonic sound field. In this study, in order to explore the thickening effect of slurry under ultrasonic wave action, we examined the rheological properties with ultrasonic wave tests of UCPB and the rheological properties after ultrasonic wave tests of UCPB. We found that the rheological curve of the slurry changed; the Herschel–Bulkley (HB) model in the initial state transformed into the Bingham model under the action of ultrasound. Ultrasonic waves have a positive effect on reducing slurry viscosity and yield stress. The rheological test of the slurry with ultrasonic wave action had a positive effect on significantly reducing the apparent viscosity and initial yield stress of slurry with a 62% mass concentration. The rheological test of slurry with ultrasonic wave action and the rheological test after ultrasonic wave action both have positive effects on reducing the viscosity and yield stress of the slurry with a 64% to 68% mass concentration; the overall effect of reducing the viscosity and yield stress of UCPB is greater after ultrasonic wave action of UCPB.

Plastic viscosity of cement mortar with manufactured sand as influenced by geometric features and particle size

This paper investigates the plastic viscosity of cement mortar with manufactured sand (MS) concerning the influences of geometric features and particle size of MS. The geometric features, including overall shape, angularity and roughness, of MS with various particle sizes were evaluated by aspect ratio, convexity area ratio, convexity perimeter ratio and circularity. The plastic viscosity of cement mortar was calculated based on the Bingham model. Results show that the combined effects of overall shape, angularity and roughness provide coarser MS particles with lower circularity. In terms of relative plastic viscosity, Robinson model shows optimal fittings for all mixtures and is thus used to determine the packing fraction of MS under shearing. From the particle packing viewpoint, shear-induced orientation increases the packing fraction of non-spherical MS particles from the random loose packing fraction and the influence is increasingly prominent with the decrease of circularity. The relative volume fraction is an important parameter influencing the relative plastic viscosity of mixtures with MS while the relative paste film thickness (R_PFT), calculated from the real packing fraction and specific surface area (SSA), is found as the dominating factor. The dependence of plastic viscosity of cement mortar on geometric features and particle size of MS can be attributed to their influences on the packing fraction and SSA of particles.