View Mixing Parameters

The database applies mixing rules to the pure-fluid Helmholtz energies. In some cases, it may be possible to improve the agreement between the calculated properties and experimental measurements by altering these rules. However, great care must be used in altering these rules, because they can greatly change the calculated properties. This command is not intended for the casual user.

The mixing rules are applied to binary pairs of mixture constituents. It may be necessary to select the pair you wish to view or alter. The fluids in the currently defined mixture are listed at the left. Only one pair at a time can be selected. To change the fluids, simply select a new fluid, and the fluid selected first will be unmarked so that only two will be checked.

Shown at the right is the currently defined mixing rule for the selected binary pair and the associated parameter values. Different rules can be chosen by clicking on the down arrow button at the right of the rule box. The parameter values can also be changed. No error checking is provided on these values, so take care when changing the mixing rules. Also, note that changing the mixing parameters can change the critical parameters associated with the mixture.

Clicking the Apply button accepts the mixing rules and values as displayed, replacing the stored values. The binary pair can then be changed so that additional mixing rules can be entered. The OK button accepts the ‘Applied’ mixing rules, and closes the dialog. The Reset button restores the mixing rules for each binary pair to their original (as shipped) state. Note that the ‘Apply’ button must be clicked before viewing the next binary pair, or any changes will not be saved.

At the bottom of the dialog, documentation is provided briefly describing the mixing rule. You can select part or all of the text in this box. The Copy button copies the selected text to the Clipboard that can then be pasted into another application.