Correlation 38 (Viscosity Correlation)

The following table lists the identification numbers of this correlation with respect to some well-known sources of thermodynamic data.

The equation has the following form:

where

rL is the saturated liquid density in kmol/m3

VP is the saturation vapor pressure in kPa

This equation supports only Kelvin (K) and Rankine (R) temperature units.

You must use at least 3 coefficients with this correlation.

While this correlation shows the calculation for the natural logarithm (ln) of the temperature-dependent property, the software calculates either the natural logarithm or the logarithm base 10 (log) of the temperature-dependent property based on your Log Basis selection in AVEVA Thermodynamic Data Manager (TDM). The default logarithm basis is the natural logarithm.

You can use up to 6 coefficients with this correlation.

You cannot use this correlation to model the saturated liquid density or the saturation vapor pressure because this results in infinite recursions.

You may have data for the coefficients that you have derived by using different UOMs for rL and VP than the UOMs needed for this correlation (kmol/m3 and kPa, respectively). In this case, you must modify your coefficients to align with the necessary UOMs. See Convert UOMs for Correlation 38 for more information on how to do this.

Usage

We recommend that you use this correlation to calculate only the following property:

• Liquid Viscosity