Formula for calculating water viscosity
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What factors affect water viscosity? What is its formula?
The viscosity of liquid water is highly dependent on temperature, with little effect from pressure; generally, the influence of pressure is corrected by using a correlation diagram between pressure and temperature. The viscosity of water that I come across is generally available in reference books, while the viscosity of mixtures of water with other substances is calculated.
It is covered in both fluid mechanics and principles of chemical engineering; please read it carefully. It can also be found in many books on water. It is available in the appendix of Volume 1 of Principles of Chemical Engineering.
The viscosity of water is highly dependent on temperature.
μ=1/(2.1482*((T-8.435)+(8078.4+(T-8.435)^2)^0.5)-120)/10 Pa*s
It can also be calculated using software like Spen Plus and the like
It is closely related to temperature; one can simply look up information when needed, as there seems to be no fixed formula.
This post was last edited by wiseboy on 2011-4-21 20:06. (1) There are many formulas, and more than one format. Although the formulas vary, the calculation results are not very different. It’s not just water; almost all pure liquid substances have this property ； (2) Liquid mixtures also have formulas similar to those of pure substances, except that the parameters in these formulas need to be calculated using the \"mixing rules\" ； (3) The regression results for most of the empirical formulas have very high accuracy, with errors not exceeding 5%. Using formulas based on molecular structures (groups), the error also meets engineering requirements. Hint: (1) The theory and calculation of liquid viscosity are among the topics studied in molecular thermodynamics and transport properties ； (2) Please refer to the monographs on thermodynamics by scholars such as Hu Ying, Ma Peisheng, Zhang Yuying, Zhang Kewu, and others.
Reply to 8# wiseboy: Yeah, I’ll give it a look if I get the chance. Thanks
Just a reminder that the temperature in the formula is in Celsius, not absolute temperature