# Newton's Law Of Viscosity

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The viscosity The viscosity is the fraction between surfaces that are completely separated is due to the internal fraction of the liquid, or it's the fluid's resistance to flow (Schmid et al, 2004). Newton’s law of viscosity defines the viscosity as the ratio of shear stress to shear rate for a given temperature and pressure. The fluids follow the Newton’s law of viscosity called Newtonian fluids where the viscosity is independent of the shear rate (constant). The fluids do not obey the Newton’s law of viscosity called Non-Newtonian where the viscosity is dependent on the shear rate (is not constant). Dynamic viscosity is the coefficient of viscosity as defined in Newton’s law of viscosity. Kinematic viscosity is the dynamic viscosity divided…show more content…
The viscosity behavior of binary mixtures is very complex and depending on the mixing ratio as shown in Fig. (1.3) Fig. (2.2): The viscosity of mixtures of two solvents as a function of the mass fraction of the second component (Kulicke et al, 2004). 2.3 The viscosity and Temperature The viscosity of liquids decreases as temperature increases (White, 1992; Themelis, 1995). As temperature increases, the average speed of the molecules in a liquid increases and the amount of time they spend in contact with their nearest neighbors decreases, then the average intermolecular forces decrease (Elert, 1998-2015). The viscous forces in a fluid are due to two causes are the intermolecular cohesive forces and molecular momentum transfer. Liquids molecules are close together, then the intermolecular cohesive forces dominate the molecular momentum transfer, and the intermolecular cohesive forces decreases with temperature increases. As a result of the intermolecular cohesive forces decreasing, the viscosity also…show more content…
The critical exponents describing these relationships are universal and should depend only on a universality class determined by the order – parameter and spatial dimensionality of the system. Binary fluid mixtures, liquid – vapor systems, and uniaxial ferromagnetic materials are thought. To belong to the three dimensional, Ising model which renormalization group (RG) context, predicts vlaues for the critical exponents. (Flewelling et al, 1996) In the binary reactive mixture the chemical is slowing down near the critical points, the reaction rate is expected to vanish like [〖T-T〗_c/T_c ]ϒ , where the critical exponent ϒ ̴ 1.25. In a ternary reactive system with one chemical reaction the rate depends on T like [〖T-T〗_c/T_c ] α , where the critical exponent α ̴ 0.12 (Jortner et al, 1982). Critical power laws represent the asymptotic behavior of a number of properties when the critical point is approached along specific thermodynamic paths (Sengers, 1980). There is a number of thermophysical properties exhibit power law behavior, whiche observed only on particular themodynamic paths that lead to the critical