Shear‐Thickening (“Dilatancy”) in Suspensions of Nonaggregating Solid Particles Dispersed in Newtonian Liquids

1989 ◽  
Vol 33 (2) ◽  
pp. 329-366 ◽  
Author(s):  
H. A. Barnes
Keyword(s):  
Shear Thickening ◽  
Solid Particles ◽  
Newtonian Liquids

scholarly journals Effect of nano-solid particles on the mechanical properties of shear thickening fluid (STF) and STF-Kevlar composite fabric

2021 ◽  
Vol 16 ◽  
pp. 155892502110448
Author(s):  
Mingmei Zhao ◽  
Jinqiu Zhang ◽  
Zhizhao Peng ◽  
Jian Zhang
Keyword(s):  
Mechanical Properties ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Tensile Force ◽  
Shear Thickening ◽  
Solid Particles ◽  
Time Range ◽  
Shear Thickening Fluid ◽  
Pull Out ◽  
Diamond Particles

To analyze the effect of nano-solid particles on the mechanical properties of shear thickening fluid (STF) and its Kevlar composite fabric. In this study, nano-silica and polyethylene glycol (PEG 200) were used as dispersed and continuous phases. Nano-graphite and nano-diamond particles were used as additives to prepare STF and Kevlar composite fabric. Study the friction characteristics and rheological characteristics of STF at different temperatures. Explore the STF’s mechanical response under transient high-speed impact conditions through the split Hopkinson pressure bar experiment. The mechanical properties of STF-Kevlar fabric are studied through yarn pull-out test and burst experiments. The experimental results show that the intermolecular repulsive force of STF is enhanced under a high-temperature environment, and shear thickening effect is reduced. Nano-diamond particles strengthen the contact coupling force and contact probability between the particle clusters, so that the maximum viscosity of the system reaches 1679 Pa s, the thickening ratio reaches 318 times, and the rheological properties of the shear thickening fluid are improved. The results of the SHPB experiment show that the STF can complete a dynamic response within a 50–75 µs time range, and the maximum stress can reach 78 MPa. The bullet’s incident kinetic energy is not only transformed into thermal energy and phase change energy of solid-liquid conversion, but also into frictional energy between particles. The mechanical experiments of STF-Kevlar composite fabrics show that the tensile force value of STF5-Kevlar is the largest (10.3 N/13.5 N), and the tensile force of neat Kevlar was the smallest (4.3 N/4.9 N). The maximum bearing capacity (0.3 kN) and absorption energy (51.8 J) of Neat Kevlar are less than those of STF1-Kevlar (3.2 kN, 116.7 J) and STF3-Kevlar (1.9 kN, 88.2 J), and STF5-Kevlar (4.7 kN, 143.3 J). Fabric’s failure mode is converted from partial yarn extraction to overall deformation and rupture of the fabric. Therefore, by changing the solid additives’ parameters, the STF and the composite fabric’s mechanical properties can be effectively controlled, which provides a reference for preparing the STF and fabric composite materials.

scholarly journals Effect of Anionic Polyacrylamide on the Structural Stability of Thickened Tailings Slurry in Pipeline Transportation

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Shi Wang ◽  
Shuai Li ◽  
Jian-chun Qin ◽  
Guang-zhe Xiao ◽  
Guo-chun Yang ◽  
...  
Keyword(s):  
Structural Stability ◽  
Shear Thickening ◽  
Solid Particles ◽  
Structure Stability ◽  
Pipeline Transportation ◽  
Shear Tests ◽  
Hindered Settling ◽  
Fine Tailings ◽  
Thickened Tailings ◽  
Anionic Polyacrylamide

Taking the superfine tailings slurry (STS), fine tailings slurry (FTS), and unclassified tailings slurry (UTS) of a gold mine as examples, a series of laboratory shear tests were conducted to investigate the effect of anionic polyacrylamide (APAM) on the structural stability of the thickened tailings slurry in pipeline transportation. Experimental results showed that the FTS and UTS had shear-thinning and shear-thickening characteristics in the constant shear tests, respectively. After addition of APAM, when the shear rate was 30 s−1, standard deviations of apparent viscosity of FTS, UTS, and STS were 66.67%, 61.40%, and 35.33% lower, respectively. APAM enhances the strength of the flocculent structures, inhibits the hindered settling of the coarse-particle tailings, improves the structure stability of the solid particles on the structural plane, and assists pipeline transportation of the thickened tailings slurry.

scholarly journals Empirical Modelling of Nonmonotonous Behaviour of Shear Viscosity

2013 ◽  
Vol 2013 ◽  
pp. 1-4 ◽  
Author(s):  
J. David ◽  
P. Filip ◽  
A. A. Kharlamov
Keyword(s):  
Shear Viscosity ◽  
Extreme Points ◽  
Shear Thickening ◽  
Local Maximum ◽  
Shear Thinning ◽  
Algebraic Form ◽  
Complex Behaviour ◽  
Empirical Modelling ◽  
Newtonian Liquids ◽  
Almost All

Almost all hitherto proposed empirical models used for characterization of shear viscosity of non-Newtonian liquids describe only its monotonous course. However, the onset of new materials is accompanied by more complicated characteristics of their behaviour including nonmonotonous course of shear viscosity. This feature is reflected not only in an existence of one extreme point (maximum or minimum), but also it can appear in both extreme points; that is, this shear viscosity initially exhibits shear thinning; after attaining a local minimum, it converts to shear thickening, and again after reaching a local maximum, it has a shear-thinning character. It is clear that, for an empirical description of this complex behaviour, a hitherto, used number of parameters (four, five) in classical monotonous models (such as Cross or Carreau-Yasuda) are no longer tenable. If more parameters are applied, there should be given an emphasis on a relatively simple algebraic form of the proposed models, unambiguity of the involved parameters, and their sound interpretation in the whole modelling. This contribution provides an overview of the existing empirical nonmonotonous models and proposes a new 10-parameter model including a demonstration of its flexibility using various experimental data.

Shear Thickening Behaviour of Composite Propellant Suspension under Oscillatory Shear

2016 ◽  
Vol 66 (3) ◽  
pp. 222 ◽  
Author(s):  
D. Singh ◽  
G. Dombe ◽  
C. Bhongale ◽  
P. P. Singh ◽  
Mehilal Maurya ◽  
...  
Keyword(s):  
Strain Amplitude ◽  
Loss Modulus ◽  
Shear Thickening ◽  
Rheological Behaviour ◽  
Complex Viscosity ◽  
Solid Particles ◽  
Dynamic Moduli ◽  
Composite Propellant ◽  
Plateau Region ◽  
Temperature Constant

Composite propellant suspensions consist of highly filled polymeric system wherein solid particles of different sizes and shapes are dispersed in a polymeric matrix. The rheological behaviour of a propellant suspension is characterised by viscoplasticity and shear rate and time dependant viscosity. The behaviour of composite propellant suspension has been studied under amplitude sweep test where tests were performed by continuously varying strain amplitude (strain in %, γ) by keeping the frequency and temperature constant and results are plotted in terms of log γ (strain amplitude) vs logGʹ and logGʺ (Storage modulus and loss modulus, respectively). It is clear from amplitude sweep test that dynamic moduli and complex viscosity show marked increase at critical strain amplitude after a plateau region, infering a shear thickening behaviour.

Surface Temperature and Heat Transfer Conditions in the Ablation of Shear Thinning and Shear Thickening Liquids

1969 ◽  
Vol 91 (1) ◽  
pp. 105-110
Author(s):  
B. Steverding
Keyword(s):  
Mass Transfer ◽  
Shear Rate ◽  
Heat And Mass Transfer ◽  
Shear Thickening ◽  
Nose Radius ◽  
Newtonian Viscosity ◽  
Rate Dependent ◽  
Viscosity Behavior ◽  
Newtonian Liquids ◽  
Dependent Viscosity

The heat and mass transfer conditions for the ablation of Newtonian liquids have been described in a number of excellent articles. However, little attention has been paid to the behavior of non-Newtonian liquids for which the viscosity is not only a function of temperature but also of shear rate. This is astonishing since many excellent ablators behave in a non-Newtonian manner, especially when they contain foreign particles such as gas bubbles. The purpose of this paper is to study changes in heat and mass transfer if the ablator has a shear rate dependent viscosity. As a result of this study it will be shown that deviations from normal Newtonian behavior increase with increasing shear stress and decreasing bluntness of the cone. Surface temperatures are calculated as a function of Mach number, degree of non-Newtonian viscosity parameter, nose radius, and altitude. Numerical results are given for a model substance with the physical characteristics of Pyrex glass but with a hypothetically varying degree of non-Newtonian viscosity behavior.

scholarly journals New Generalized Viscosity Model for Non-Colloidal Suspensions and Emulsions

Fluids ◽  
2020 ◽  
Vol 5 (3) ◽  
pp. 150
Author(s):  
Rajinder Pal
Keyword(s):  
Volume Fraction ◽  
Colloidal Suspensions ◽  
High Ratio ◽  
Solid Particles ◽  
Viscosity Model ◽  
Viscosity Data ◽  
Liquid Droplets ◽  
Newtonian Liquids ◽  
Liquid Suspensions ◽  
Induced Aggregation

The viscous behavior of solids-in-liquid suspensions and liquid-in-liquid emulsions of non-Brownian solid particles and liquid droplets dispersed in Newtonian liquids is thoroughly discussed and reviewed. The full concentration range of the dispersed particles/droplets is covered, that is, 0<ϕ<ϕm, where ϕ is the volume fraction of inclusions (particles or droplets) and ϕm is the maximum packing volume fraction of inclusions. The existing viscosity models for suspensions and emulsions are evaluated using a large pool of experimental viscosity data on suspensions and emulsions. A new generalized model for the viscosity of suspensions and emulsions is proposed and evaluated. The model takes into consideration the influence of shear-induced aggregation of particles and droplets. It also includes the effect of the droplet-to-matrix viscosity ratio λ on the viscosity of emulsions. In the limit of high ratio of droplet viscosity to matrix viscosity (λ→∞), the model reduces to the suspension viscosity model. The proposed model uncovers some important and novel characteristics of suspension systems rarely discussed heretofore in the literature. The model is validated using twenty sets of experimental viscosity data on solids-in-liquid suspensions and twenty-three sets of experimental viscosity data on liquid-in-liquid emulsions.

Thixotropic Strength and Thixotropic Criteria in Semi-Solid Processing

2008 ◽  
Vol 141-143 ◽  
pp. 319-323 ◽  
Author(s):  
W.C. Keung ◽  
Y.F. Lee ◽  
Wei Wei Shan ◽  
Shou Jing Luo
Keyword(s):  
Shear Stress ◽  
Shear Rate ◽  
Shape Factor ◽  
Shear Thickening ◽  
Solid Material ◽  
Solid Content ◽  
Solid Particles ◽  
Thixotropic Behavior ◽  
Semi Solid ◽  
Constant Shear Rate

Thixotropy is essential to semi-solid processing, and because of it the semi-solid material is characterized by ‘shear shinning’. Here, thixotropic strength and thixotropic criteria in semi-solid processing are put forward based on related theories and experiments, and thixotropic mechanism and its influencing factors are also investigated. The results are as follows: 1) the term of thixotropic strength means that with constant shear rate at semi-solid temperature, the semi-solid body begins to flow when the shear stress reach a certain value. This value of shear stress is defined as the thixotropic strength; 2) Thixotropic behavior happens with ‘shear thinning’ because of the deagglomeration of solid particles, while ‘shear thickening’ happens because of the agglomeration at the same time. With increasing shear time, the shear stress increases first and then decreases rapidly to reach a stable value. 3) There are three important factors that influence ‘thixotropic strength’: temperature (hence solid content), initial microstructure (including size, shape factor and uniformity of solid particles) and shear rate.

The Instability of Shear Thinning and Shear Thickening Spiralling Liquid Jets: Linear Theory

2006 ◽  
Vol 128 (5) ◽  
pp. 968-975 ◽  
Author(s):  
J. Uddin ◽  
S. P. Decent ◽  
M. J. Simmons
Keyword(s):  
Asymptotic Methods ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Wave Mode ◽  
Linear Instability ◽  
Liquid Jets ◽  
Flow Index ◽  
Rotation Rates ◽  
Newtonian Liquids ◽  
Small Rotation

The linear instability of a power law liquid emerging as a jet from an orifice on the surface of a rotating container is investigated, with applications to industrial prilling. Asymptotic methods are used to examine the growth rate and wavenumber of the most unstable traveling wave mode for different flow index numbers. Comparison with Newtonian liquids show that for small rotation rates shear thinning liquids are most stable to disturbances. In contrast for higher rotation rates we find shear thickening liquids are more stable than shear thinning liquids. The influence of viscosity, surface tension, and rotation rate on the growth rates and most unstable wavenumbers associated with both types of liquids are also examined.

scholarly journals Rheological and Technological Aspects in Designing the Properties of Shear Thickening Fluids

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6585
Author(s):  
Radosław Żurowski ◽  
Paweł Falkowski ◽  
Justyna Zygmuntowicz ◽  
Mikołaj Szafran
Keyword(s):  
Kinetic Energy ◽  
Functional Properties ◽  
Raw Materials ◽  
Shear Thickening ◽  
Dissipation Factor ◽  
Solid Content ◽  
Solid Particles ◽  
Raw Material ◽  
Protective Properties ◽  
Shear Thickening Fluids

This work focuses on shear thickening fluids (STFs) as ceramic–polymer composites with outstanding protective properties. The investigation aims to determine the influence of raw material parameters on the functional properties of STFs. The following analyses were used to characterize both the raw materials and the STFs: scanning electron microscopy, dynamic light scattering, matrix-assisted laser desorption/ionization time-of-flight, chemical sorption analysis, rheological analysis, and kinetic energy dissipation tests. It was confirmed that the morphology of the solid particles plays a key role in designing the rheological and protective properties of STFs. In the case of irregular silica, shear thickening properties can be obtained from a solid content of 12.5 vol.%. For spherical silica, the limit for achieving shear thickening behavior is 40 vol.%. The viscosity curve analysis allowed for the introduction of a new parameter defining the functional properties of STFs: the technological critical shear rate. The ability of STFs to dissipate kinetic energy was determined using a unique device that allows pure fluids to be tested without prior encapsulation. Because of this, it was possible to observe even slight differences in the protective properties between different STFs, which has not been possible so far. During tests with an energy of 50 J, the dissipation factor was over 96%.

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