Viscosities of binary liquid mixtures

Eyring deduced a relationship between viscosity and molar volume of a pure liquid on theoretical considerations. Katti and Chaudhri assumed that the molar free energy of activation of flow of a mixture is an additive property and derived an equation correlating viscosity of an ideal mixture with molar volumes and composition. This expression was further modified for non-ideal mixtures by introducing a work function to represent the deviation from ideal behaviour. The validity of this equation was examined using binary mixtures in which intramolecular and intermolecular interactions are present. It is concluded that this equation is not applicable to binary mixtures of components which exhibit self-association.     

Molecular clustering in binary liquid mixtures

Proceedings - Mathematical Sciences - The earlier investigations on the intensity and depolarisation of the transversely scattered light in liquid mixtures in the neighbourhood of the critical...     

Theoretical evaluation of sound velocities in binary liquid mixtures containing triethyl amine

The sound velocity in binary mixtures of organic liquids containing triethylamine, a weakly polar molecule as the common component, has been evaluated theoretically, based on the Free Length Theory (F.L.T.) of Jacobson and Collision Factor Theory (C.F.T.) of Schaaffs. The results are presented along with the experimental values. The two theories, applied to mixtures of triethylamine with Benzene, Cyclohexane, Dioxan, O-xylene, Toluene, Pyridine and Aniline, are compared. The theoretical values appear to be in reasonable agreement with experimental values.     

On the viscosities of liquid mixtures

There have been many empirical formulae proposed which would give the viscosity of a binary mixture of liquids in terms of the viscosities of the liquids and of the composition. Several years ago kinetic theory arguments were used to rederive an old formula due to Dolezalek and Schulze, which has the virtue of simplicity and, apparently, good accuracy. The parameters of this formula are the two fluid viscosities and a mutual viscosity. In this note we observe that such formulae fit exactly into the continuum theory of mixtures recently developed by us and others. We use Dolezalek's and Schulze's formula and thermodynamic restrictions, elsewhere derived, to present a generalized Navier-Stokes system for the flow of mixtures of liquids.

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Zusammenfassung Es sind viele empirische Formeln vorgeschlagen worden, die die Viskosität einer Mischung von zwei Flüssigkeiten als Funktion der Viskositäten der beiden Flüssigkeiten ausdrückt. Vor mehreren Jahren wurden Argumente aus der kinetischen Theorie benützt, um eine alte Formel von Dolezalek und Schulze wieder herzuleiten, die den Vorzug der Einfachheit hat und anscheinend ziemlich genau ist. In dieser Arbeit wird bemerkt, dass solche Formeln exakt in die Kontinuumstheorie von Mischungen passen, die vor kurzem von den Autoren und von andern entwickelt wurde. Wir benützten die Formel von Dolezalek und Schulze und thermodynamische Einschränkungen, die anderswo abgeleitet wurden, um eine verallgemeinertes Navier-Stokes-System für die Strömung von Mischungen von Flüssigkeiten anzugeben.

     

Boundary value problems in the theory of binary mixtures

In this paper, the boundary value problems of steady oscillation (vibration) of the linear theory of thermoelasticity for binary mixtures are investigated by means of the boundary integral equation method (potential method). The uniqueness and existence theorems of solutions of the exterior boundary value problems by means potential method and multidimensional singular integral equations are proved. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Propagation of weak discontinuities in binary mixtures of ideal gases

The propagation of the weak discontinuities in binary non-reacting mixtures of classical ideal monoatomic gases is analyzed. The normal speeds of propagation are determined and compared with those of a single fluid. The differential equation governing the growth and the decay of the acceleration waves is obtained and the solutions for plane, cylindrical and spherical waves are shown. The influence of the different atomic masses of the constituents is also investigated.     

An analytical solution for conduction-dominated unidirectional solidification of binary mixtures

In this paper, a fully analytical solution technique is established for the solution of unidirectional, conduction-dominated, alloy solidification problems. By devising appropriate averaging techniques for temperature and phase-fraction gradients, governing equations inside the mushy region are made inherently homogeneous. The above formulation enables one to obtain complete analytical solutions for solid, liquid and mushy regions, without resorting to any numerical iterative procedure. Due considerations are given to account for variable properties and different microscopic models of alloy solidification (namely, equilibrium and non-equilibrium models) in the two-phase domain. The results are tested for the problem of solidification of a NH₄Cl–H₂O solution, and compared with those from existing analytical models as well as with the corresponding results from a fully numerical simulation. The effects of different microscopic models on solidification behaviour are illustrated, and transients in temperature and heat flux distribution are also analysed. A good agreement between the present solutions and results from computational simulation is observed.