ZDF

Zone Definition file
File type: Various data file
Files with zdf extension are used to store boundary grid information for each zone. This helps to transport files between computers faster.
Found 2 different file type records with the same zdf filename suffix.
What is zdf file?
File type category:
Various data file
Date updated: June 29, 2017
The file with zdf extension is a common file that contains only the boundary grid information for each zone. This makes for a smaller file for transporting between machines and also makes access quicker.
Common files use a flexible binary direct access file architecture. This allows grid data for multizone structured grids and their associated boundary condition data to be stored in the same file. It also supports overlapping grids and unstructured grids.
A Zone Definition File (ZDF) is a formatted ascii file from the McDonnell Douglas surface grid generator ZONI3G.
Z-Firm document folder
File type category:
Various data file
Date updated: January 22, 2018
The zdf file extension is associated with some applications developed by the Z-Firm company.
The zdf file stores document folder.
Seems to be obsolete file format without support from developer or producer.