Matrix viscosity model

The matrix viscosity model is used to determine the viscosity from measured data supplied at specific temperatures, shear rates, and pressures.

To be able to use the matrix viscosity model, the raw data that you enter must comply with the following rules:

• The data must be entered in the following columns:

  • Temperature (deg C)
  • Shear rate (1/s)
  • Pressure (MPa)
  • Viscosity (Pa.s)

• The data points should be listed in order of increasing temperature.

• Group the data points into blocks of the same temperature.

• Each temperature should have the same number of data points associated with it; the blocks should be of equal size.

• Within each temperature block, the data points must be arranged in order of increasing shear rate.

• The same set of shear rates should be used in each block.

• If the data is pressure dependent, all of the temperature "blocks" should repeat for each pressure.

• If the data is independent of pressure, the pressure column should contain zeroes.

• There should be no redundant entries (two data points with the same temperature and shear rate).

Viscosity interpolation (between data points) and extrapolation (outside the data point range) is done on log(viscosity) versus pressure, temperature, and log(shear rate).

Example of matrix viscosity data