Investigation of the Flow Behavior of Participate Filled Fluids

1996 ◽  
Vol 445 ◽  
Author(s):  
T. E. Driscoll ◽  
P. C. Li ◽  
G. L. Lehmann ◽  
E. J. Cotts
Keyword(s):  
Large Particle ◽  
Capillary Flow ◽  
Flow Behavior ◽  
Solid Particles ◽  
Spherical Particles ◽  
Liquid Density ◽  
High Concentration ◽  
Flow Process ◽  
Fluid Mixture ◽  
Underfill Flow

AbstractUnderfill encapsulants, used in direct‐chip‐attachment (DCA) packaging of electronics, consist of an epoxy resin in which a high concentration of solid particles are suspended. As a fluid mixture key features of these encapsulants are their relatively large particle sizes and large particle‐to‐liquid density ratios (ρs/ρ0 ?2.4). Experiments have been conducted to characterize the flow behavior of model mixtures of negatively buoyant, spherical particles suspended in Newtonian liquids. Capillary flow in a parallel surface channel is used to simulate the underfill flow process. The effects of varying the channel spacing, particle size and liquid carrier are reported here. The flow behavior is contrasted with a linear fluid, effective viscosity model. Particle settling appears to be linked to the more complex behavior observed in both our model suspensions and measurements using an actual commercial encapsulant.

scholarly journals Slip Effects on Peristaltic Transport of a Particle-Fluid Suspension in a Planar Channel

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Mohammed H. Kamel ◽  
Islam M. Eldesoky ◽  
Bilal M. Maher ◽  
Ramzy M. Abumandour
Keyword(s):  
Amplitude Ratio ◽  
Muscular Contraction ◽  
Slip Condition ◽  
Spherical Particles ◽  
Free Fluid ◽  
Mean Flow ◽  
Two Phase ◽  
Flow Process ◽  
Fluid Mixture ◽  
Slip Conditions

Peristaltic pumping induced by a sinusoidal traveling wave in the walls of a two-dimensional channel filled with a viscous incompressible fluid mixed with rigid spherical particles is investigated theoretically taking the slip effect on the wall into account. A perturbation solution is obtained which satisfies the momentum equations for the case in which amplitude ratio (wave amplitude/channel half width) is small. The analysis has been carried out by duly accounting for the nonlinear convective acceleration terms and the slip condition for the fluid part on the wavy wall. The governing equations are developed up to the second order of the amplitude ratio. The zeroth-order terms yield the Poiseuille flow and the first-order terms give the Orr-Sommerfeld equation. The results show that the slip conditions have significant effect within certain range of concentration. The phenomenon of reflux (the mean flow reversal) is discussed under slip conditions. It is found that the critical reflux pressure is lower for the particle-fluid suspension than for the particle-free fluid and is affected by slip condition. A motivation of the present analysis has been the hope that such theory of two-phase flow process under slip condition is very useful in understanding the role of peristaltic muscular contraction in transporting biofluid behaving like a particle-fluid mixture. Also the theory is important to the engineering applications of pumping solid-fluid mixture by peristalsis.

A Comparison of Oil-Water Flow and Oil-Gas Flow in Capillary Model

2012 ◽  
Author(s):  
Yihe Zhang ◽  
Liming Dai
Keyword(s):  
Pressure Drop ◽  
Liquid Film ◽  
Gas Flow ◽  
Capillary Flow ◽  
Flow Behavior ◽  
Thin Liquid Film ◽  
Flow Process ◽  
Capillary Model ◽  
Oil Water ◽  
Oil Gas

A capillary model is employed to study the slug flow behavior in pore structure. Oil-water system and oil-gas system are investigated in the experiments. During the flow process, it is observed that the wetting phase liquid will generate a thin liquid film on the inner surface of the tube wall, and the liquid film plays an important role in capillary flow. At the meantime, the pressure drop across the tube is recorded during the experiment, result shows that the pressure drop magnitude is proportional to the oil slug length, while it is not significantly affected by the liquid injecting velocity.

Behaviors of Spherical and Nonspherical Particles in a Square Pipe Flow

2011 ◽  
Vol 9 (5) ◽  
pp. 1179-1192 ◽  
Author(s):  
Takaji Inamuro ◽  
Hirofumi Hayashi ◽  
Masahiro Koshiyama
Keyword(s):  
Polar Angle ◽  
Immiscible Fluids ◽  
Solid Particles ◽  
Spherical Particles ◽  
Nonspherical Particles ◽  
Fluid Mixture ◽  
Spherical Droplet ◽  
Liquid Boundary ◽  
Boltzmann Method ◽  
Solid Liquid

AbstractThe lattice Boltzmann method (LBM) for multicomponent immiscible fluids is applied to the simulations of solid-fluid mixture flows including spherical or non-spherical particles in a square pipe at Reynolds numbers of about 100. A spherical solid particle is modeled by a droplet with strong interfacial tension and large viscosity, and consequently there is no need to track the moving solid-liquid boundary explicitly. Nonspherical (discoid, flat discoid, and biconcave discoid) solid particles are made by applying artificial forces to the spherical droplet. It is found that the spherical particle moves straightly along a stable position between the wall and the center of the pipe (the Segré-Silberberg effect). On the other hand, the biconcave discoid particle moves along a periodic helical path around the center of the pipe with changing its orientation, and the radius of the helical path and the polar angle of the orientation increase as the hollow of the concave becomes large.

Underflow Process for Direct-Chip-Attachment Packaging

1998 ◽  
Vol 515 ◽  
Author(s):  
P. C. Li ◽  
G. L. Lehmann ◽  
J. Cascio ◽  
T. Driscoll ◽  
Y. J. Huang ◽  
...  
Keyword(s):  
Flip Chip ◽  
Capillary Flow ◽  
Flow Behavior ◽  
Complex Function ◽  
Plane Channel ◽  
Flow Process ◽  
Wetting Properties ◽  
Solder Bumps ◽  
Flip Chip Packaging ◽  
Measured Flow

ABSTRACTIn flip-chip packaging an underfill mixture is placed into the chip-to-substrate standoff created by the array of solder bumps, using a capillary flow process. The flow behavior is a complex function of the mixture properties, the wetting properties, and the flow geometry. This paper reports on the use of a plane channel capillary flow to characterize underfill materials. The measured flow behavior provides evidence that both the contact angle (θ) and the suspension viscosity (μapp) vary with time under the Influence of changing flow conditions. This nonlinear fluid behavior is modeled for the flow of both model suspensions and commercial underfill materials using an extended Washburn model.

Peristaltic Transport of a Particle-Fluid Suspension

1989 ◽  
Vol 111 (2) ◽  
pp. 157-165 ◽  
Author(s):  
L. M. Srivastava ◽  
V. P. Srivastava
Keyword(s):  
Particle Concentration ◽  
Amplitude Ratio ◽  
Flow Reversal ◽  
Spherical Particles ◽  
Free Fluid ◽  
Mean Flow ◽  
Two Phase ◽  
Flow Process ◽  
Fluid Mixture ◽  
The Mean

Peristaltic pumping by a sinusoidal traveling wave in the walls of a two-dimensional channel filled with a viscous incompressible fluid in which are distributed identical rigid spherical particles, is investigated theoretically. A perturbation solution is obtained which satisfies the momentum equations for the case in which amplitude ratio (wave amplitude/channel half width) is small. The results show that the fluid phase mean axial velocity decreases with increase in the particle concentration. The phenomenon of reflux (the mean flow reversal) is discussed. A reversal of velocity in the neighborhood of the centerline occurs when the pressure gradient is greater than that of the critical reflux condition. It is found that the critical reflux pressure is lower for the particle-fluid suspension than for the particle-free fluid. It is further observed that the mean flow reversal is strongly dependent on the particle concentration and the presence of particles in the fluid favors the reversal flow. A motivation of the present analysis has been the hope that such a theory of two-phase flow process is very useful in understanding the role of peristaltic muscular contraction in transporting bio-fluid behaving like a particle-fluid mixture. Also the theory is important to the engineering applications of pumping solid-fluid mixtures by peristalsis.

scholarly journals SOME TECHNICAL ASPECTS OF THE RHEOLOGICAL PROPERTIES OF HIGH CONCENTRATION FINE SUSPENSIONS TO AVOID ENVIRONMENTAL DISASTERS

2015 ◽  
Vol 23 (2) ◽  
pp. 129-137 ◽  
Author(s):  
József FAITLI ◽  
Imre GOMBKÖTŐ
Keyword(s):  
Raw Materials ◽  
Flow Behavior ◽  
Energy Requirement ◽  
Industrial Applications ◽  
Solid Particles ◽  
Rheological Parameters ◽  
High Concentration ◽  
Rotational Viscometer ◽  
Mixture Flow ◽  
Baia Mare

The behavior of slurries and suspensions made by mixing solid particles and liquids is very important for various industrial applications. The latest accidental failure events at tailings facilities (Kolontár, Baia Mare) have focused public interest into this field. Nowadays, environmental practice is turning to use dry deposition techniques or at least as high concentration slurries or pastes as possible, to avoid large spills in case of an accidental failure of an embankment. High concentration slurries are becoming widely accepted in many environmentally related operations such as underground backfilling or simple tailings deposition. However, the hydraulic transport of pastes or high density slurries requires higher energy input via pumps, and, in addition, the energy requirement or pressure loss calculation methods are also different because the rheology of pastes differs from that of dilute slurries. At the University of Miskolc, Institute of Raw Materials Preparation and Environmental Processing, Miskolc, Hungary, this topic has been studied for many decades. The fine suspension – coarse mixture flow model was introduced, and it has been determined that the flow behavior of fine suspensions made of solid particles smaller than a limit particle size can be measured and interpreted in almost the same way as for single phase clear liquids. Based on these measured rheological parameters of fine suspensions, the frictional energy loss can be calculated. The aim of this paper is to give a summary and data base about the rheological behavior of different industrial materials based on pilot scale hydraulic loop measurements. An Anton-Paar rotational viscometer and a tube viscometer with three measuring pipe sections,– developed by our institute – were used for testing. The results of measurements of various granular materials, such as sands, fly ashes, perlite, tailings and red mud are presented in connection with environmental applications. Based on these results, empirical relationships are presented, where the parameters are determined by simple function fitting into the data of measurements carried out at discrete concentration values. The rheology of fine suspensions of any concentration up to the measured maximum can be calculated by these relationships.

Analysis of flow behavior of size distributed spherical particles in screw feeder

2020 ◽  
Author(s):  
Dheeraj Minglani ◽  
Abhishek Sharma ◽  
Harsh Pandey ◽  
Ram Dayal ◽  
Jyeshtharaj B. Joshi
Keyword(s):  
Flow Behavior ◽  
Spherical Particles ◽  
Screw Feeder

Film Elasticity and Film Stabilization in Firefighting Foam Stabilized by Solid Particles

2017 ◽  
Vol 744 ◽  
pp. 346-349
Author(s):  
Xiu Juan Li ◽  
Rui Song Guo ◽  
Min Zhao
Keyword(s):  
Life Time ◽  
Liquid Films ◽  
Thin Liquid Films ◽  
Solid Particles ◽  
High Concentration ◽  
Hydration Effect ◽  
Fixed Area ◽  
The Stability ◽  
Hydration Layers ◽  
Hydration Forces

The structure of the thin liquid films determines the stability of foams and emulsions. In this work the bubbles stretched length with different hollow SiO2 particles concentration is measured when the foam has been stilled for different time. The results show that the bubbles stretched length is longer than that of bubbles when the foam is free of hollow SiO2 particles even when the foam has been stilled for 500mins. The bubbles stretched length increases with increasing the concentration of hollow SiO2 particles. A strong hydration effect leaves a large volume of hydration layers on the solid particles surfaces in aqueous solutions. The water in hydration layers can help the film keep a certain thickness. The existence of hydration forces leads that two particles cannot be too close each other. The high concentration surfactant limited in the fixed area helps the film keep good elasticity. Therefore the film has a long life time with compatible thickness and elasticity and the three-phrase foam is upper stable.

Analysis of flow behavior of cohesive monosized spherical and non-spherical particles in screw feeder

2021 ◽  
pp. 117049
Author(s):  
Dheeraj Minglani ◽  
Abhishek Sharma ◽  
Harsh Pandey ◽  
Jyeshtharaj B. Joshi
Keyword(s):  
Flow Behavior ◽  
Spherical Particles ◽  
Screw Feeder

Raman-Microsampling Technique Applying Optical Levitation by Radiation Pressure

1984 ◽  
Vol 38 (1) ◽  
pp. 78-83 ◽  
Author(s):  
R. Thurn ◽  
W. Kiefer
Keyword(s):  
Radiation Pressure ◽  
Optical Potential ◽  
Solid Particles ◽  
Spherical Particles ◽  
Exciting Light ◽  
Potential Wells ◽  
Ion Laser ◽  
Optical Levitation ◽  
Argon Ion ◽  
Microprobe Technique

We report on a new Raman microprobe technique where micron-sized solid particles are trapped in stable optical potential wells using only the force of radiation pressure from a continuous gas laser. We demonstrate this technique with Raman spectra from spherical and non-spherical particles of sizes ranging between 10–30 μm. The particles are stably supported by a vertical directed focused TEM00-mode cw argon ion laser of ∼500 mW. The latter simultaneously serves as the exciting light source. Several suggestions for improvements of this technique are made.

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