Rheological and Flocculated Properties of Silver Nanoparticles Paste

2011 ◽  
Vol 236-238 ◽  
pp. 2197-2201
Author(s):  
Yu Yang Zhang ◽  
Shi Xing Wang
Keyword(s):  
Silver Nanoparticles ◽  
Shear Rate ◽  
Volume Fraction ◽  
Loss Modulus ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Low Frequency ◽  
Particle Volume ◽  
Solids Loading ◽  
Bismuth Subgallate

Silver nanoparticles pastes were formatted by mixing different volumetric silver nanoparticles with the mixture of 12.7wt% bismuth subgallate and 87.3wt% organic vehicle. Rheological and flocculated properties of silver nanoparticles pastes were examined. All pastes demonstrated pseudoplastic flow behaviors and shear thinning characters over the solids-loading and shear-rate range studied. The viscosities of pastes reduce with increasing the shear rate in a logarithmic plot. G' (storage modulus) and G" (loss modulus) increase with increasing silver nanoparticles content and frequency. At high loading, G' and G" begin to level off and exhibit plateau in the low-frequency range. The appearance of the plateau at low frequency is due to the presence of silver nanoparticles in the system and forming the three-dimensional network structure. The shear stress increases with increasing silver nanoparticles content. Apparent yield value estimated by casson equation exhibits a power-law dependence on particle volume fraction.

scholarly journals New patterns in high-speed granular flows

2015 ◽  
Vol 769 ◽  
pp. 218-228 ◽  
Author(s):  
Nicolas Brodu ◽  
Renaud Delannay ◽  
Alexandre Valance ◽  
Patrick Richard
Keyword(s):  
High Speed ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Scaling Law ◽  
Three Dimensional ◽  
Secondary Flows ◽  
Particle Volume ◽  
Rheological Models ◽  
Granular Gas ◽  
Internal Structures

We report on new patterns in high-speed flows of granular materials obtained by means of extensive numerical simulations. These patterns emerge from the destabilization of unidirectional flows upon increase of mass holdup and inclination angle, and are characterized by complex internal structures, including secondary flows, heterogeneous particle volume fraction, symmetry breaking and dynamically maintained order. In particular, we evidenced steady and fully developed ‘supported’ flows, which consist of a dense core surrounded by a highly energetic granular gas. Interestingly, despite their overall diversity, these regimes are shown to obey a scaling law for the mass flow rate as a function of the mass holdup. This unique set of three-dimensional flow regimes raises new challenges for extending the scope of current granular rheological models.

Vortex Simulation for Behavior of Solid Particles Falling in Air

2011 ◽  
Author(s):  
Hisanori Yagami ◽  
Tomomi Uchiyama
Keyword(s):  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Air Flow ◽  
Three Dimensional ◽  
Particle Diameter ◽  
Vortex Method ◽  
Solid Particles ◽  
Particle Volume ◽  
Two Phase ◽  
Spherical Region

The behavior of small solid particles falling in an unbounded air is simulated. The particles, initially arranged within a spherical region in a quiescent air, are made to fall, and their fall induces the air flow around them, resulting in the gas-particle two-phase flow. The particle diameter and density are 1 mm and 7.7 kg/m3 respectively. A three-dimensional vortex method proposed by one of the authors is applied. The simulation demonstrates that the particles are accelerated by the induced downward air flow just after the commencement of their fall. It also highlights that the particles are whirled up by a vortex ring produced around the downward air flow after the acceleration. The effect of the particle volume fraction at the commencement of the fall is also explored.

The 3-D Finite Element Analysis on Elastic-Plastic Micromechanical Response of the Particle Volume Fraction

2019 ◽  
Vol 962 ◽  
pp. 210-217
Author(s):  
Yong Ming Guo ◽  
Nozomi Fukae
Keyword(s):  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Particle Volume ◽  
Two Phase ◽  
Element Analysis ◽  
Elastic Plastic ◽  
Microstructural Parameters ◽  
Commercial Software Package ◽  
Properties Of Materials

It is well known that the properties of materials are a function of their microstructural parameters. The FEM is a good selection for studies of three-dimensional microstructure-property relationships. In this research, the elastic-plastic micromechanical response of the particle volume fraction of two-phase materials have been calculated using a commercial software package of the FEM, some new knowledges on the microstructure-property relationships have obtained.

Numerical Investigation on the Effect of Abrasive Property for Abrasive Flow Machining

2014 ◽  
Vol 574 ◽  
pp. 406-410
Author(s):  
Li Feng Yang ◽  
Chun Yan Dong ◽  
Wei Na Liu
Keyword(s):  
Material Removal ◽  
Volume Fraction ◽  
Metal Removal ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Three Dimensional Model ◽  
Particle Volume ◽  
Micro Holes ◽  
Micro Hole ◽  
Abrasive Property

Numerical investigations of the abrasive influence on material removal efficiency of the micro-hole for AFM process is conducted in this paper. A three-dimensional model is constructed for this process. The abrasive with various particles volume fraction and different micro-holes with various diameters are selected in this study. The simulation results show that the lower particle volume fraction may be in favour of the metal removal uniformity, but the processing time will be too long if too low fraction is selected.

The Effect of Using Nanofluids on Triangular Microchannel Heat Exchanger Performance

2010 ◽  
Author(s):  
G. Bhaskaran ◽  
H. A. Mohammed ◽  
N. H. Shuaib
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Volume Fraction ◽  
Numerical Study ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Hydrodynamic Performance ◽  
Particle Volume ◽  
Microchannel Heat Exchanger

A numerical study is performed to study the effects of using various types of nanofluids on a triangular shaped microchannel heat exchanger (MCHE). The performance of an aluminum MCHE with various types of nanofluids such as Al2O3, CuO, SiO2, Ag and TiO2 and diamond particles with particle volume fraction of 2% using water as base fluid is comprehensively analyzed. The three-dimensional steady, laminar developing flow and conjugate heat transfer of a balanced MCHE were solved using finite volume method. In order to maintain laminar flow in the microchannels, Re number was ranged from 100 to 800. The other parameters tested in this study include the effects of Reynolds number towards the temperature, effectiveness and pressure drop of the MCHE. It is found that nanofluids have improved the temperature profile and heat transfer rate of the MCHE. The increase in pressure drop was minimal while the thermal and hydrodynamic performance of the heat exchanger was enhanced.

scholarly journals On Unsteady Three-Dimensional Axisymmetric MHD Nanofluid Flow with Entropy Generation and Thermo-Diffusion Effects

2017 ◽  
Author(s):  
Mohammed Almakki ◽  
Sharadia Dey ◽  
Sabyasachi Mondal ◽  
Precious Sibanda
Keyword(s):  
Nusselt Number ◽  
Thermal Radiation ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Linearization Method ◽  
Physical Parameters ◽  
Particle Volume ◽  
Nanofluid Flow

We investigate entropy generation in unsteady three-dimensional axisymmetric MHD nanofluid flow over a non-linearly stretching sheet. The flow is subject to thermal radiation and a chemical reaction. The conservation equations were solved using the spectral quasi-linearization method. The novelty of the work is in the study of entropy generation in three-dimensional axisymmetric MHD nanofluid and the choice of the spectral quasilinearization method as the solution method. The effects of Brownian motion and thermophoresis are also taken into account when the nanofluid particle volume fraction on the boundary in passively controlled. The results show that as the Hartman number increases, both the Nusselt number and the Sherwood number decrease whereas the skin friction increases. It is further shown that an increase in the thermal radiation parameter corresponds to a decrease in the Nusselt number. Moreover, entropy generation increases with the physical parameters.

Hybrid Particle/Fiber Polymer Based Composites Analysis Based on DMA Data vs. Material Property Predictions

2014 ◽  
Vol 659 ◽  
pp. 101-106
Author(s):  
Dana Motoc Luca
Keyword(s):  
Volume Fraction ◽  
Loss Modulus ◽  
Unsaturated Polyester ◽  
Particle Volume Fraction ◽  
Dynamic Mechanical Properties ◽  
Damping Factor ◽  
Hybrid Polymer ◽  
Particle Volume ◽  
Material Development ◽  
Numerical Predictions

The paper aims a comparison with respect to the dynamic mechanical properties of few hybrid polymer based composite architectures based on experimental data against micro-mechanical models based numerical predictions. The hybrid polymer based composites considered were particle-fiber combinations reinforced within an unsaturated polyester resin to provide different architectures. Variations in storage modulus (E’), loss modulus (E’’) and damping factor (tan δ) with temperature increase and different particle volume fraction were investigated. Data comparison reveals the herein composite architectures’ performances over the benchmark and enables further insight into the material development and characterization issues.

Flow of Nano and Micron Size Particles in a Cylindrical Cavity

2008 ◽  
Author(s):  
Suresh Ahuja
Keyword(s):  
Shear Rate ◽  
Tensile Stress ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Continuum Models ◽  
Particle Volume ◽  
Cohesive Stress ◽  
Shear Cell ◽  
Particle Level ◽  
Complicated Geometries

Flow of particles is analyzed by considering driving force from applied shear energy (rotating augers). against constraints of extrinsic constraints (consolidation, boundary) and intrinsic constraints (cohesion, compressibility and inter-particle forces). Both Discrete Element Method (DEM) and Continuum Models are used to analyze powder flow with DEM uses models at particle level and is therefore requires costly computation where as Continuum Models are less accurate for complicated geometries and free surfaces. The cohesive (tensile) stress for an assembly of cohesive particles is an increasing function of volume fraction but depends only weakly on shear rate. As the particle volume fraction is decreased, the dependence of the tensile stress on shear rate grows, but for all volume fractions, this dependence is much weaker than that of the total stress. Empirical correlations are costly to obtain for predicting developer flow from frequent bench experiments (Freeman tester, Jenike shear cell and Seville tester) and tests in fixtures and housings. A rheological equation can be used to analyze shear stress, normal stress, cohesive stress and dynamic coefficient of friction in a shear cell. Experimental results are compared with the existing models.

3D Numerical Analysis for the Inelastic Deformation of Rubber Particle Modified Polymers

2004 ◽  
Vol 261-263 ◽  
pp. 717-722
Author(s):  
Tie Jun Wang ◽  
Wen Xu Zhang ◽  
Kikuo Kishimoto ◽  
Mitsuo Notomi
Keyword(s):  
Inelastic Deformation ◽  
Volume Fraction ◽  
Rubber Particle ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Shear Loading ◽  
Loading Conditions ◽  
Particle Volume ◽  
Modified Polymers ◽  
Three Dimensional Finite Element

Body-centered cubic unit cell models and three-dimensional finite element method are used to study the inelastic deformation of rubber particle modified polymers. Calculations are carried out for three loading conditions, i.e. uniaxial loading, plane strain deformation loading and the so-called 'equivalent shear' loading. Distributions of the localized shear deformation are presented to understand the microscopic deformation mechanisms of the polymers. Effects of particle size, particle volume fraction and loading conditions on the micro- and macroscopic deformation behavior of rubber particle modified polymers are discussed.

scholarly journals Numerical Simulation of Free Convection in a Partially Heated Three-Dimensional Enclosure Filled with Ionanofluid ([C4mim][NTf2]-Cu)

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Said Bouchta ◽  
M’barek Feddaoui ◽  
Abdellatif Dayf
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Free Convection ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Three Dimensional ◽  
Particle Volume ◽  
Simplec Algorithm ◽  
Current Lines ◽  
Volume Method

A numerical analysis was performed to study free convection in a stationary laminar regime in a partially heated cube filled with ionanofluid. To numerically solve the dimensionless equations, we applied the finite volume method using the SIMPLEC algorithm for pressure correction. All walls are adiabatic, except for the left and right side walls which are partially heated differently. At the end of this simulation, several results are given in the form of current lines, isotherms, and variations in the Nusselt number. These results are obtained by analyzing the effect of a set of factors such as Rayleigh number, particle volume fraction, cold and source position on the dynamic and thermal fields, and heat transfer. It has been shown that the percentage of nanoparticles and high Rayleigh numbers significantly increase heat transfer by ionanofluid. Two comparisons have been made, between ionic fluid and ionanofluid at isotherms and streamlines, and between nanofluid and ionanofluid at Nusselt number, which show the advantage of using ionanofluid in heat transfer.

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