With MolFlow 2.3.5, two long-requested features have been added to the expressions that you can use in Formula Editor.

1) Mean Free Path / Mean Pumping Path

Adding the "MFP" or "MPP" variables will display the mean free/pumping path in centimeters, that is, the total length travelled by particles in the system divided by the number of hits / number of absorbed particles.

2) Sums for selection groups

MolFlow now fully supports defining part of the geometry as selection groups. In the formula editor, it is now possible to refer to a group of facets and perform sum operation on them. The syntax is the following:

sum(prefix,Sn)

where prefix can be:

• AR (area of facets)
• A (number of absorbed particles)
• H (nimber of hits on the facets)
• D (number of particles desorbed from the facets)

Examples:

• SUM(A,S3) will calculate the total number of particles absorbed on facets that are part of selection group 3
• SUM(AR,S1) tells the total area of all facets in selection group 1