Complex fluids are the fluids for which the classical fluid mechanics discussed in Section 3.1.4 is found to be inadequate. This is because the internal structure in them evolves on the same time scale as the hydro-dynamic fields (85). The role of state variables in the extended fluid mechanics that is suitable for complex fluids play the hydrodynamic fields supplemented with additional fields or distribution functions that are chosen to characterize the internal structure. In general, a different internal structure requires a different choice of the additional fields. The necessity to deal with the time evolution of complex fluids was the main motivation for developing the framework of dynamics and thermodynamics discussed in this review. There is now a large amount of papers in which the framework is used to investigate complex fluids. In this review we shall list only a few among them. The list below is limited to recent papers and to the papers in which I was involved. [Pg.110]

C / -classical fluid mechanics and np-particle kinetic theory... [Pg.113]

Commonly used simulation programs are based on a numerical solution of the onedimensional classical fluid mechanics equation by the method of characteristics [1-2]. For numerical simulation the piping system is devided in sections with constant cross-sectional areas which are connected by knot-elements. [Pg.578]

Bernoulli s general theorem applied to the field consisting of the upstream reservoir, the die and the free surface of the extruded rod, shows that [33] the head loss in the isochoric flow is the sum of two terms. The first term is the usual volume term, responsible for the pressure loss in classical fluid mechanics. For purely viscous materials, this term represents the power dissipated due to viscosity, in the whole volume of the flowing fluid. The second term is representative of the energy dissipated along the surface of the walls. Its value is... [Pg.393]

The flow of liquids or semisolids is described by viscosity, or, more precisely, by shear viscosity (unit Pa sec). The viscosity defines the resistance of the material against flow. Viscosity is not a coefficient, because it is a function of the shear strain rate y [ti = /(y)]. In the classical fluid mechanics, the dynamic viscosity is obtained using a viscometer. (A viscometer is a rheometer, i.e., an instrument for the measurement of rheological properties, limited to... [Pg.3129]

The thermodynamics of irreversible processes should be set up from the scratch as a continuum theory, treating the state parameters of the theory as field variables [32]. This is also the way in which classical fluid mechanic theory is formulated. Therefore, in the computational fluid dynamics literature, the transport phenomena and the extensions of the classical thermodynamic relations are both interpreted as closures of the fluid dynamic theory. The validity of the thermodynamic relations for fluid dynamic systems has been approached from the viewpoint of the kinetic theory of gases [13]. However, any Arm distinction between irreversible thermodynamics and fluid mechanics... [Pg.38]

As for many immobilised enz3nnes, the hydraulic behaviour Is not adequately described by classical fluid mechanics. It was, therefore, necessary to develop a detailed mathematical model of the column hydraulics which together with a laboratory test procedure, would provide data on the basic mechanical properties of the enzyme pellet. The model Is based on a force balance across a differential element of the enzyme bed. The primary forces involved are fluid friction, wall friction, solids cohesion, static weight and buoyancy. The force balance Is integrated to provide generating functions for fluid pressure drop and solid stress pressure down the length of the column under given conditions. [Pg.144]

It is not implausible that there are worlds whose ultimate constituents are Newtonian particles conforming to Newtonian-like laws, worlds whose ultimate constituents are fluids obeying classical fluid mechanics, worlds whose ontology and laws are those of Bohmian quantum mechanics, all of which contain configurations that realize the nomological/causal specifications associated with at least some mental properties. [Pg.46]

When the flow is isothermal and the liquid has a viscosity that can be taken to be independent of pressure (ie, rj is constant over the entire flow field), substitution of equations 1 and 2 into the balance of linear momentum leads to the Navier-Stokes equations, which have been the subject of intense study in classical fluid mechanics for more than a century. [Pg.6730]

Serrin, J., Mathematical Principles of Classical Fluid Mechanics, in Handbuch der Physik, Bd. VIII/1 S. Flugge and C. Truesdell, Eds., Springer-Verlag, Berlin, 1959. [Pg.45]

Section 3, For early classical fluid-mechanical theory of a moving contact line, see... [Pg.38]

Much of the early development of classical fluid mechanics was concerned with the mathematics of ideal (inviscid) fluids, i.e. fluids which have zero viscosity (Batchelor, 1967). In an ideal fluid, the shear stress is always zero even when the fluid is flowing. In this case, the momentum flux across the surface of a control volume would be by convection only. Figure 3.2 shows... [Pg.39]

The theoretical formulation of heat and mass transfer in porous media is usually obtained by a change in scale. We can pass from a microscopic view where the size of tlie representative volume is small with regards to pores, to a microscopic view where the size of the representative volume CO is large with regard to the pores. Moreover, the heat and mass transfer equations can be deduced from Whitaker s theory. The macroscopic equations can be obtained by averaging the classical fluid mechanics, dififiision and transfer equations over the averaging volume co[m ]. The average of a function/is ... [Pg.208]

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