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Shearing flow

In a simple plane Couette shearing flow, as depicted at the top of Fig. 1-5, there is only one nonzero velocity component, namely ui, and it varies only in direction 2, the direction orthogonal to the plates. Hence Vv is [Pg.23]


Figure A3.1.5. Steady state shear flow, illustrating the flow of momentum aeross a plane at a height z. Figure A3.1.5. Steady state shear flow, illustrating the flow of momentum aeross a plane at a height z.
Theoretically the apparent viscosity of generalized Newtonian fluids can be found using a simple shear flow (i.e. steady state, one-dimensional, constant shear stress). The rate of deformation tensor in a simple shear flow is given as... [Pg.5]

In addition to the apparent viscosity two other material parameters can be obtained using simple shear flow viscometry. These are primary and secondary nomial stress coefficients expressed, respectively, as... [Pg.5]

Kaye, A., Lodge, A. S. and Vale, D. G., 1968. Determination of normal stress difference in steady shear flow. Rheol. Acta 7, 368-379. [Pg.189]

Non-Newtonian Fluids Die Swell and Melt Fracture. Eor many fluids the Newtonian constitutive relation involving only a single, constant viscosity is inappHcable. Either stress depends in a more complex way on strain, or variables other than the instantaneous rate of strain must be taken into account. Such fluids are known coUectively as non-Newtonian and are usually subdivided further on the basis of behavior in simple shear flow. [Pg.95]

Fig. 10. Fluid behavior in simple shear flow where A is Bingham B, pseudoplastic C, Newtonian and D, dilatant. Fig. 10. Fluid behavior in simple shear flow where A is Bingham B, pseudoplastic C, Newtonian and D, dilatant.
Pseudoplastic fluids are the most commonly encountered non-Newtonian fluids. Examples are polymeric solutions, some polymer melts, and suspensions of paper pulps. In simple shear flow, the constitutive relation for such fluids is... [Pg.96]

Consistent with this model, foams exhibit plug flow when forced through a channel or pipe. In the center of the channel the foam flows as a soHd plug, with a constant velocity. AH the shear flow occurs near the waHs, where the yield stress has been exceeded and the foam behaves like a viscous Hquid. At the waH, foams can exhibit waH sHp such that bubbles adjacent to the waH have nonzero velocity. The amount of waH sHp present has a significant influence on the overaH flow rate obtained for a given pressure gradient. [Pg.430]

Hardness. The Knoop indentation hardness of vitreous sihca is in the range of 473—593 kg/mm and the diamond pyramidal (Vickers) hardness is in the range of 600—750 kg/mm (1 4). The Vickers hardness for fused quartz decreases with increasing temperature but suddenly decreases at approximately 70°C. In addition, a small positive discontinuity occurs at 570°C, which may result from a memory of quartz stmcture (165). A maximum at 570°C is attributed to the presence of small amounts of quartz microcrystals (166). Scanning electron microscopic (sem) examination of the indentation area indicates that deformation is mainly from material compaction. There is htfle evidence of shear flow (167). [Pg.506]

Plastic Forming. A plastic ceramic body deforms iaelastically without mpture under a compressive load that produces a shear stress ia excess of the shear strength of the body. Plastic forming processes (38,40—42,54—57) iavolve elastic—plastic behavior, whereby measurable elastic respoase occurs before and after plastic yielding. At pressures above the shear strength, the body deforms plastically by shear flow. [Pg.308]

The force is direcdly proportional to the area of the plate the shear stress is T = F/A. Within the fluid, a linear velocity profile u = Uy/H is estabhshed due to the no-slip condition, the fluid bounding the lower plate has zero velocity and the fluid bounding the upper plate moves at the plate velocity U. The velocity gradient y = du/dy is called the shear rate for this flow. Shear rates are usually reported in units of reciprocal seconds. The flow in Fig. 6-1 is a simple shear flow. [Pg.630]

The Prandtl mixing length concept is useful for shear flows parallel to walls, but is inadequate for more general three-dimensional flows. A more complicated semiempirical model commonly used in numerical computations, and found in most commercial software for computational fluid dynamics (CFD see the following subsection), is the A — model described by Launder and Spaulding (Lectures in Mathematical Models of Turbulence, Academic, London, 1972). In this model the eddy viscosity is assumed proportional to the ratio /cVe. [Pg.672]

The drag force is exerted in a direction parallel to the fluid velocity. Equation (6-227) defines the drag coefficient. For some sohd bodies, such as aerofoils, a hft force component perpendicular to the liquid velocity is also exerted. For free-falling particles, hft forces are generally not important. However, even spherical particles experience lift forces in shear flows near solid surfaces. [Pg.676]

Secondly, the pressure drop, P, in the above expression is the pressure drop due to shear flow along the die. If a pressure transducer is used to record the... [Pg.372]

David.son, L, Large eddy simulation A dynamic one-equation subgrid model for three-dimensional recirculating flow. In llth Int. Symp. on Turbulent Shear Flow, vol. 3, pp. 26.1-26.6, Grenoble, 1997. [Pg.1058]

Adler, P.M., 1981. Heterocoagulation in shear flow. Journal of Colloid and Interface Science, 83, 106-115. [Pg.299]

Pope, S.B., 1979. Probability distribution in turbulent shear flows. In Turbulent shear flows 2. Berlin Springer, pp. 7-16. [Pg.318]

P. A. Thompson, M. O. Robbins. Shear flow near solids epitaxial order and flow boundary conditions. Phys Rev A 47 6830-6837, 1990. [Pg.73]

Molecular dynamics, in contrast to MC simulations, is a typical model in which hydrodynamic effects are incorporated in the behavior of polymer solutions and may be properly accounted for. In the so-called nonequilibrium molecular dynamics method [54], Newton s equations of a (classical) many-particle problem are iteratively solved whereby quantities of both macroscopic and microscopic interest are expressed in terms of the configurational quantities such as the space coordinates or velocities of all particles. In addition, shear flow may be imposed by the homogeneous shear flow algorithm of Evans [56]. [Pg.519]

M. Kroger, R. Makhloufi. Wormlike micelles under shear flow A microscopic model studied by nonequihbrium molecular dynamics computer simulations. Phys Rev E 55 2531-2536, 1996. [Pg.552]

A. Milchev, J. Wittmer, D. P. Landau. A Monte Carlo study of equilibrium polymers in a shear flow. Europ Phys J B 1999 (in press). [Pg.552]

Liquids are able to flow. Complicated stream patterns arise, dependent on geometric shape of the surrounding of the liquid and of the initial conditions. Physicists tend to simplify things by considering well-defined situations. What could be the simplest configurations where flow occurs Suppose we had two parallel plates and a liquid drop squeezed in between. Let us keep the lower plate at rest and move the upper plate at constant velocity in a parallel direction, so that the plate separation distance keeps constant. Near each of the plates, the velocities of the liquid and the plate are equal due to the friction between plate and liquid. Hence a velocity field that describes the stream builds up, (Fig. 15). In the simplest case the velocity is linear in the spatial coordinate perpendicular to the plates. It is a shear flow, as different planes of liquid slide over each other. This is true for a simple as well as for a complex fluid. But what will happen to the mesoscopic structure of a complex fluid How is it affected Is it destroyed or can it even be built up For a review of theories and experiments, see Ref. 122. Let us look into some recent works. [Pg.766]

FIG. 15 A colloidal suspension subject to shear flow. The arrows indicate the mean particle velocities. [Pg.766]

Figure 10 shows that upon cessation of shear flow of the melt, shear stress relaxation of LLDPE is much faster than HP LDPE because of the faster reentangle-... [Pg.281]

Viscosities of the blends and composites were measured in shear flow with a Gottfert Rheograph 2002 capillary viscosimeter. The shear rate was investigated from 100-10000 s" . The L D ratio of the capillary die was 30 mm 1 mm. Rabinowitch correction was made to the measurements, but Bagley correction was not applied. [Pg.625]

Concerning a liquid droplet deformation and drop breakup in a two-phase model flow, in particular the Newtonian drop development in Newtonian median, results of most investigations [16,21,22] may be generalized in a plot of the Weber number W,. against the vi.scos-ity ratio 8 (Fig. 9). For a simple shear flow (rotational shear flow), a U-shaped curve with a minimum corresponding to 6 = 1 is found, and for an uniaxial exten-tional flow (irrotational shear flow), a slightly decreased curve below the U-shaped curve appears. In the following text, the U-shaped curve will be called the Taylor-limit [16]. [Pg.690]

To constitute the We number, characteristic values such as the drop diameter, d, and particularly the interfacial tension, w, must be experimentally determined. However, the We number can also be obtained by deduction from mathematical analysis of droplet deforma-tional properties assuming a realistic model of the system. For a shear flow that is still dominant in the case of injection molding, Cox [25] derived an expression that for Newtonian fluids at not too high deformation has been proven to be valid ... [Pg.695]

Similar folds—fo ds that have the same geometric form, but where shear flow in the plastic beds has occurred (sec Figure 2-4.5). [Pg.250]

From the results obtained in [344] it follows that the composites with PMF are more likely to develop a secondary network and a considerable deformation is needed to break it. As the authors of [344] note, at low frequencies the Gr(to) relationship for Specimens Nos. 4 and 5 (Table 16) has the form typical of a viscoelastic body. This kind of behavior has been attributed to the formation of the spatial skeleton of filler owing to the overlap of the thin boundary layers of polymer. The authors also note that only plastic deformations occurred in shear flow. [Pg.55]

During dynamic measurements frequency dependences of the components of a complex modulus G or dynamic viscosity T (r = G"/es) are determined. Due to the existence of a well-known analogy between the functions r(y) or G"(co) as well as between G and normal stresses at shear flow a, seemingly, we may expect that dynamic measurements in principle will give the same information as measurements of the flow curve [1],... [Pg.75]

At least, in absolute majority of cases, where the concentration dependence of viscosity is discussed, the case at hand is a shear flow. At the same time, it is by no means obvious (to be more exact the reverse is valid) that the values of the viscosity of dispersions determined during shear, will correlate with the values of the viscosity measured at other types of stressed state, for example at extension. Then a concept on the viscosity of suspensions (except ultimately diluted) loses its unambiguousness, and correspondingly the coefficients cn cease to be characteristics of the system, because they become dependent on the type of flow. [Pg.85]

If we consider a shear flow of a diluted suspension of noninteracting particles, then substitution of spheres by particles of ellipsoidal form leads only to a variation of... [Pg.88]


See other pages where Shearing flow is mentioned: [Pg.31]    [Pg.238]    [Pg.5]    [Pg.15]    [Pg.98]    [Pg.308]    [Pg.630]    [Pg.630]    [Pg.258]    [Pg.362]    [Pg.461]    [Pg.34]    [Pg.767]    [Pg.586]    [Pg.586]    [Pg.587]    [Pg.587]    [Pg.690]   
See also in sourсe #XX -- [ Pg.387 ]

See also in sourсe #XX -- [ Pg.78 ]




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Alignment by shear or extensional flow

Anisotropy in a Simple Steady-State Shear Flow

Applications of Shear Flow

Arbitrary linear shear flow

Axisymmetric shear flow

Axisymmetric straining shear flow

Behavior in strong transverse shear flows

Bubble Dynamics and Mass Transfer in Shear Flow

Capillary flow, shear viscosity

Cessation of steady shear flow

Circular Cylinder in a Simple Shear Flow

Circular cylinder shear flows

Coagulation in Laminar Shear Flow

Coagulation laminar shear flow

Cone-and-Plate Viscometery under Shear-Flow Cytometry

Convective Shear flow, role

Couette Shear Flow between Coaxial Cylinders

Couette-shear flow

Cylinder shear flow

Diffusion to a Circular Cylinder in Shear Flows

Dynamic shear flow

Elongation and Shear Flows

Elongational shear-free flows

Example---shear flow

Example. 1-D laminar flow of a shear-thinning polymer melt

F Start-Up of Simple Shear Flow

Flow at High Shear Rates

Flow behavior shear-thickening

Flow behavior shear-thinning

Flow laminar shear

Flow shear viscosity

Flow-induced phenomena of lyotropic polymer liquid crystals the negative normal force effect and bands perpendicular to shear

Fluid Vesicles in Shear Flow

Fluid flow shear-stress

Fluid vesicles, shear flow

Governing Equations for Shear Flow

Granular flows, solids shear

Hard spheres shear flow

Heat Transfer from a Rotating Cylinder in Simple Shear Flow

Homogeneous instability in shear flow

Instability of Two-Dimensional Unidirectional Shear Flows

Intermittent Shear Flow of Thermotropic Main-Chain LCPs

Linear Straining Shear Flow. Arbitrary Peclet Numbers

Linear Straining Shear Flow. High Peclet Numbers

Linear shear flow

Linearity, consequences shear flow

Liquids shearing flow

Mass transfer plane shear flow

Mass transfer shear flow

Mass transfer simple shear flow

Mass transfer translational-shear flow

Material Functions for Oscillatory Shear Flow

Material Functions for Steady-State Shear Flow

Mixing process shear flow

Motion shear flow

Nebulizers flow-shear

Non-Isothermal Shear Flow

Non-Linear Effects in Simple Shear Flow

Non-Steady-State Shear Flow

Non-linear Response in Time-dependent Shearing Flows

Nonlinear Shear Flows

Nonlinear viscoelasticity shear thinning flow

Normal Steady shear flow

Normal Stresses during Shear Flow

Normal stress differences in steady-state shear flow

Oscillatory Shear Flow Solutions

Oscillatory shear flow

Oscillatory shear flow instability

Oscillatory shear flow measurement

Oscillatory shear flow stability

Particle of Arbitrary Shape in a Linear Shear Flow

Particle shear flow field

Pipe flow wall shear rate

Planar shear flow

Plane shear flow

Plastic shear flow

Powder flow Jenike shear cell

Predicting the Striation Thickness in a Couette Flow System - Shear Thinning Model

Pure shear flow

Recoil after Cessation of Steady Shearing Flow

Rheological flows simple shear flow

Rheology steady shear flow

Roll instability in shear flow

Screw Shear flow

Second-Order Fluids in Simple Shearing Flow

Shear Flow Around a Circular Cylinder

Shear Heating in Couette Flow

Shear Recovery after steady Shearing Flow

Shear Stokes flow

Shear Viscous Flow

Shear aggregation turbulent flow

Shear effect, flow-enhanced

Shear flow

Shear flow Shift factor

Shear flow between parallel plates

Shear flow boundary conditions

Shear flow characteristics

Shear flow compounding

Shear flow critical

Shear flow curve

Shear flow definition

Shear flow direction

Shear flow experiments

Shear flow extensional

Shear flow field

Shear flow isothermal

Shear flow modified

Shear flow near a boundary

Shear flow outputs from a slot or cylindrical die

Shear flow phenomenon

Shear flow steady simple

Shear flow stress

Shear flow thickening

Shear flow unsteady simple

Shear flow, uniform

Shear flow-induced birefringence

Shear flow/rates

Shear free flow

Shear gradients, flow/viscosity

Shear rate streamline flow

Shear rate turbulent flow

Shear rotating disk flow

Shear sine-flow

Shear stress potential flow

Shear thickening materials flow curve

Shear thinning flow

Shear thinning materials flow curve

Shear viscosity, extensional flow

Shear, flow measurements

Shear-Driven Flow

Shear-Flow Driven Combustion Instability

Shear-Free Flow Material Functions

Shear-flow cytometry

Shear-free flow measurements

Shear-rate-dependent flow

Shearing Flow and Other Methods

Shearing Flow with Constant Stress

Shearing flow defined

Shearing of Flow-Aligning Nematics

Simple shear flow

Simple shear flow dissipation

Simple shear flow dynamic sinusoidal varying

Simple shear flow invariants

Simple shear flow normal stresses

Simple shear flow rheological response

Simple shear flow start

Simple shear flow steady solutions

Simulations of Steady Shearing Flows

Simulations of Transient Start-Up Shear Flows

Single-phase fluid flow shear factor

Sphere in Linear Flows Axisymmetric Extensional Flow and Simple Shear

Sphere in a simple shear flow

Sphere in shear flow

Spherical Particles, Drops, and Bubbles in Shear Flows

Spiral shearing flow

Stagnation flow surface shear stress

Start-up of steady shear flow

Start-up shear flows with tension-dissociation coupling

Steady Shearing Flow

Steady Shearing Flow of Defect-Ridden Smectics

Steady shear flow

Steady shear flow measurement

Steady shear flow of inelastic polymers

Steady shear flow results

Steady shear-free flow

Steady simple shear flow, constitutive

Steady simple shear flow, constitutive equations

Steady-State Shear Flow Measurement

Steady-State Simple Shear Flow

Steady-state shear flow

Steady-state shear flow field

Straining shear flow

Stress Decay at the Termination of Steady Shearing Flow

Stress Development at the Onset of Steady Shearing Flow

Stress Growth at Inception of Steady Shearing Flow

Stress Relaxation after Cessation of Steady Shear Flow

Stress Relaxation after Cessation of Steady Shearing Flow

Stress-strain relationship simple shear flow

Superposition of Steady Shearing Flow with Transverse Small-Amplitude Oscillations

Superposition of Steady-State Shear Flow and Small-Amplitude Oscillations

The Diffusivity Tensor for Steady-State Shear and Elongational Flows

The Effect of Viscous Dissipation on a Simple Shear Flow

The Heat-Flux Vector in Steady-State Shear and Elongational Flows

Thixotropic flow after shear thinning

Three-dimensional shear flow

Torsional shear flow, nematics

Transfer in Linear Shear Flows at Low Peclet Numbers

Transient Mass Transfer in Steady-State Translational and Shear Flows

Transient Shear Flow of Thermotropic Main-Chain LCPs

Transient Simple Shear Flow of Shvedov-Bingham Fluids

Translational and Shear Flows

Translational-shear flow

Turbulent flow shear stress

Ultra-Soft Colloids in Shear Flow

Vesicles in shear flow

Viscoelastic properties of polymer solutions in simple shear flow

Viscoelasticity shear thinning flow

Viscosity measurement shear flow capillary method

Wall shear stress-flow characteristic curves and scale-up

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