An Enhanced Herschel–Bulkley Model for Thixotropic Flow Behavior of Semisolid Steel Alloys

Pouyafar, Vahid; Sadough, S.A.

doi:10.1007/s11663-013-9900-2

Cited by 13 publications

(8 citation statements)

References 16 publications

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“…An enhanced model based on the Herschel-Bulkley equation was proposed also for other metallic alloys, as such as steels [79] and Mg alloys [80]. Pouyafar et al [79] calculated the yield stress of M2 steel from the flow curve obtained from experiments in steady-state flow by interpolation of the experimental results to evaluate the stress at zero shear rate. The enhanced model was compared to the classical one and it was found that the new model could predict in a more precise way the behavior of the material, especially at high shear rate, than the conventional one.…”

Section: Yield Stressmentioning

confidence: 99%

Rheological Characterization of Semi-Solid Metals: A Review

Modigell

Pola

Tocci

2018

Metals

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In the present review, the main findings on the rheological characterization of semi-solid metals (SSM) are presented. Experimental results are a fundamental basis for the development of comprehensive and accurate mathematics used to design the process effectively. For this reason, the main experimental procedures for the rheological characterization of SSM are given, together with the models most widely used to fit experimental data. Subsequently, the material behavior under steady state condition is summarized. Also, non-viscous properties and transient conditions are discussed since they are especially relevant for the industrial semi-solid processing.

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Section: Yield Stressmentioning

confidence: 99%

Rheological Characterization of Semi-Solid Metals: A Review

Modigell

Pola

Tocci

2018

Metals

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“…The prevalent correlation of shear stress and shear rate is the Herschel-Bulkley model (Kelessidis et al, 2006;Kelessidis & Maglione, 2008;Pouyafar & Sadough, 2013), a tri-parametric nonlinear correlation combining the effects of yield stress and power law behavior which outperforms the bi-parametric Bingham, power law and Casson models. The rheological parameters estimated from experimental campaigns are temperatureand concentration-dependent, and literature models are usually condition-dependent.…”

Section: Rheology Modeling and Parameter Estimationmentioning

confidence: 99%

Development and Parameter Estimation for a Multivariate Herschel-Bulkley Rheological Model of a Nanoparticle-Based Smart Drilling Fluid

Gerogiorgis¹,

Clark²,

Vryzas³

et al. 2015

12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering

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Smart drilling fluids containing Fe3O4 nanoparticles have advantages toward increasing the hydraulic efficiency of drilling operations in a variety of reservoir environments. Exploring and optimizing the rheological behavior of such new drilling fluids is critical, implying direct and significant economic savings in developing new oil and gas fields. A experimental campaign analyzing the rheology of a bentonite-based fluid produced a new multiparametric dataset, considering a wide range of realistic reservoir conditions. Non-Newtonian behaviour is confirmed by yield stress computation for all these cases. Heating and rotation induce temperature and concentration gradients at drilling depth: it is hence essential to obtain an accurate but also versatile multivariate rheological model, which will enable viscosity prediction for the analyzed and other similar drilling fluids. The enhanced Herschel-Bulkley model is developed on a multiplicative assumption, postulating and analysing candidate equations which quantify the effect of shear rate, temperature and nanoparticle concentration on drilling fluid shear stress and viscosity. Parameter estimates have been subsequently determined via systematic optimisation, using statistical metrics to quantify and compare uncertainty and predictive potential. The trivariate shear stress and viscosity models proposed are similar in form: each requires six parameters used to combine a Herschel-Bulkley yield stress expression, an Arrhenius exponential of temperature and a linear model for nanoparticle concentration.

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“…After yielding, the suspension contains nanoparticle aggregates, idealised as doublets (Flatt & Bowen, 2007). Pouyafar and Sadough (2013) suggested a further breakdown in the percolating nanoparticle isostructure under increasing shear rate; on this assumption we postulate a shear dependent average interparticle distance. It is assumed that the nanoparticle doublets are cubically distributed, increasing shear rate disperses particles into a final cubic distribution, with fixed interparticle distance (δ) which is a function of nanoparticle volume fraction as shown by Eq.…”

Section: Shear Stress Modelmentioning

confidence: 92%

“…A quasi-equilibrium condition is applied to the shear-dependant structuring term (λ τ ) in Eq. (3) (Pouyafar & Sadough, 2013). The role of the percolation threshold volume fraction (ϕ o ), at which long-range connectivity is observed, is considered in the structuring term (Flatt & Bowen, 2006).…”

Section: Shear Stress Modelmentioning

confidence: 99%

First-principles Rheological Modelling and Parameter Estimation for Nanoparticle-based Smart Drilling Fluids

Reilly

Vryzas

Kelessidis

et al. 2016

Computer Aided Chemical Engineering

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Drilling fluids serve many applications in the oil-drilling process, including the removing of cuttings, drill bit cooling and the prevention of fluid transfer to and from the rock strata. With the addition of nanoparticles it is possible to facilitate in-situ control of the drilling fluid rheology, increasing the hydraulic efficiency of drilling campaigns and reducing costs in a variety of reservoir environments. This paper proposes a first-principles approach to the rheology of smart drilling fluids containing

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An Enhanced Herschel–Bulkley Model for Thixotropic Flow Behavior of Semisolid Steel Alloys

Cited by 13 publications

References 16 publications

Rheological Characterization of Semi-Solid Metals: A Review

Rheological Characterization of Semi-Solid Metals: A Review

Development and Parameter Estimation for a Multivariate Herschel-Bulkley Rheological Model of a Nanoparticle-Based Smart Drilling Fluid

First-principles Rheological Modelling and Parameter Estimation for Nanoparticle-based Smart Drilling Fluids

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