A first approaching to work with viscosity in college level

Physica, 1967

International Journal of Scientific Research in Chemistry, 2019

The viscosity is a measure of its resistance to deformation of a liquid at a given rate and corresponds to thickness [1] Viscosity can be conceptualized as quantifying the frictional force that arises between adjacent layers of fluid that are in relative motion. Experiments show that some stress is needed to sustain the flow of the liquid. This is because a force is required to overcome the friction between the layers of the fluid which are in relative motion and the strength of this force is proportional to the viscosity. A fluid that has no resistance to shear stress is known as an ideal or inviscid fluid. Zero viscosity is observed only at very low temperatures in superfluids. Otherwise, the second law of thermodynamics requires all fluids to have positive viscosity;[2][3] such fluids are technically said to be viscous or viscid [4]. A fluid with a relatively high viscosity, such as pitch, may appear to be a solid. Dynamic and kinematic viscosity is common in fluid dynamics, which is ratio of the viscosity to the density of the fluid . The viscosity is? frequently called the dynamic viscosity or absolute viscosity . The purpose of present study is to compare the viscosity of different forms of matter.

Chemical Engineering Science, 2000

The work of Heric and Brewer (1969 Journal of Chemical Engineering Data, 14, 55}63) which involved testing a number of liquid viscosity correlations resulted in concluding that the McAllister (1960 A.I.Ch.E. Journal, 6, 427}431) model was the most accurate. However, the fact that the McAllister model is correlative in nature severely limits its practicality and usefulness. This is because costly and time-consuming data are required for the determination of the adjustable (or interaction) parameters contained in that model (Asfour, Cooper, Wu & Zahran, 1991, Industrial and Engineering Chemistry Research, 13, 1666}1669). This study reports the development of a generalized expression of the McAllister model for multi-component liquid mixtures, evaluation of the generalized McAllister model parameters, converting the McAllister model into a predictive model, and comparison of the predictive capability of generalized McAllister model with those of the GC-UNIMOD reported by Cao, Knudsen, Fredenslund and Rasmussen (1993a,b Industrial and Engineering Chemistry Research, 32, 2077}2087, 2088}2092) and with the generalized corresponding states principle (GCSP) which was reported by Teja and Rice (1981 Industrial and Engineering Chemistry, Fundamentals, 20, 77}81). The comparison clearly indicated that the generalized McAllister model is consistently far superior to the GC-UNIMOD and the GCSP in predicting the viscosities of ternary, quaternary, and quinary liquid mixtures. This, no doubt, represents a signi"cant accomplishment in the area of predicting the viscometric behaviour of multi-component liquid mixtures.

2018

Molecular interactions in binary mixtures composed of a xylene and selected 1-butanol 1-pentanol, 1-hexanol, 1-heptanol and 1-octanol was investigated by measuring the viscosity at T= 303.15 K. From experimental data, viscosity deviation was calculated. Values of viscosity deviations for all binary mixtures are negative and increase with increase of alcohols chain length. Obtained data were interpreted based on the type and magnitude of the physico-chemical interactions in the binary liquid systems. free volume theory was applied to correlate the viscosities of binary mixtures and correlated values by this model were good enough and obtained data were within the uncertainty region.Keywords: Viscosity; xylene; 1-Alkanol; free volume theory

International Journal of Thermophysics, 2001

This paper describes the application of the theoretically based scheme of Vesovic and Wakeham, modified by making use of the hard-sphere model of Dymond and Assael, to the prediction of the viscosity of liquid mixtures. The purpose of the paper is to examine this scheme in more detail than earlier to find out in what circumstances it works well and

Journal of Chemical Engineering of Japan, 1975

A simple viscosity relation for a multi-component liquid mixture was obtained by developing the relation based on statistical mechanics without using self-diffusivities. The important hypothesis employed in this work is that the average local strain energy in a binary liquid mixture displays the same density dependency as that in a single-component liquid. The viscosity of a mixture of more than three components can be divided into the contributions of the sub-binary mixtures extracted from the mixture. The viscosity of a regular solution can be estimated from the densities and viscosities of pure component liquids alone. The validities of the resultant viscosity relations were verified for several binary and ternary liquid mixtures. The viscosity of a non-regular solution was illustratively shown to be estimated by introducing an additional parameter.

International Journal of Thermophysics, 2000

Page 1. International Journal of Thermophysics, Vol. 21, No. 2, 2000 Prediction of the Viscosity of Liquid Mixtures: An Improved Approach1 MJ Assael,2, 5 NK Dalaouti,2 JH Dymond,3 E. Perperi,2 and WA Wakeham4 ... According to Di Pippo et al. ...

Mechanics, 2014

Acta Metallurgica Slovaca, 2015

The aim of the paper is to evaluate the quality of measurement process of the dynamic viscosity using the Measurement Systems Analysis and the analysis of uncertainty. The viscosity of a fluid is defined as a measure of its resistance to gradual deformation by shear stress or tensile stress. Viscosity is a property arising from collisions between neighboring particles in a fluid that are moving at different velocities. Dynamic or absolute viscosity is a measure of the internal resistance of the fluid. The measurement process is realized which of ten samples of vegetable and mineral oils, four operators and the viscometer-Rheotest-2‖. The temperature of individual oil was according to customer requirement. The process of the measurement according to the Measurement Systems Analysis is capable because the value of index %GRR is 8.85 %. Operators do not have a statistically significant effect on the measured viscosity or its uncertainty. The paper presents a procedure to calculate the uncertainty of the measured values of dynamic viscosity. In addition to possible sources of uncertainty that are reported in the available literature, the calculation is supplemented by further sources, also important according to authors.