Viscosity of simple liquids including measurement and prediction at elevated pressure

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 1976
Thesis identifier
  • T110(1976)
Qualification Level
Qualification Name
Department, School or Faculty
  • A falling body viscometer with self-centring sinkers has been developed and used to measure the viscosities of benzene, carbon tetrachloride and eight halogenated hydrocarbons at pressures up to 500 MN m⁻² in the temperature range 25˚C to 100˚C. Two isotherms of water have also been measured at pressures up to 1000 MN m⁻² . Details of the viscometer and its pressurising equipment are given together with an analysis of the performance of the system. The results are estimated to be accurate to within ±2 per cent, and show good agreement with other measured data where available. The change of viscosity with pressure for the halogenated hydrocarbons is generally similar to that of other simple liquids. The results show that liquids having molecules of similar shape also have a similar change in relative viscosity with pressure.Theories of liquid viscosity are reviewed and constants required by Eyring's significant structure theory are obtained for more than sixty liquids using literature data. Methods are derived for calculating these constants from correlations with readily available critical properties or chemical structure. The correlations are tested using the new measurements and literature data. These tests show that the methods derived work well if one or two values of viscosity at atmospheric pressure can be used but are less reliable if only structural information is available. Since at least one measured viscosity isavailable for most liquids it is concluded that the method will be useful for predicting viscosities at other temperatures and pressures.
Resource Type
Date Created
  • 1976
Former identifier
  • 992085483402996