One parameter friction theory models for viscosity

In this work the friction theory (f-theory) for viscosity modeling is used in conjunction with the SRK, PR and PRSV cubic equations of state in order to develop three one parameter general models for viscosity prediction. The models are considered one parameter models because they only require a cha racteristic critical velocity, which is a parameter normally not tabulated. The models use these rather simple cubic equations of state as a basis to obtain accurate modeling of the viscosity of fluids for wide ranges of temp erature and pressure. The general models presented in this work are based o n the viscosity behavior of n-alkanes from methane to n-octadecane. Althoug h best performance is obtained for the considered n-alkanes, a good model p erformance is also obtained for other systems. Thus, recommended characteri stic critical viscosity values for several systems are also reported in thi s work. However, in the case of n-alkanes, an empirical equation for the ch aracteristic critical viscosity is provided so that no additional parameter s are required. In addition, with the use of simple mixing rules, the visco sity of several binary to quaternary n-alkane mixtures can also be predicte d with a satisfactory accuracy. (C) 2001 Elsevier Science B.V. All rights r eserved.