In a working group, it may be required to exchange material data between different computers and users. Both material property and reaction data are stored inside the CFD-ACE+ Database. This data can be stored in different places and allow different access possibilities (privileges) depending on the type of database.

Database types

There are 3 types of database offering 3 levels of access: model, ESI-CFD, and local. The diagram in figure 1 represents these types of database and how the information can be transferred.

Figure 1.  Database manager types and information flow

Figure 2.  Database Manager layout

1. Model Level: Data will be stored inside your DTF file. It is accessible to this DTF file only. To have your data stored at the model level, you need to create it under the "Model" folder (see figure 2 above).

   Important note:
   For the data to actually be stored in the DTF file when you save it, you need to use the data somewhere in the model. For example, if you defined new species and mixtures, they need to be used as inputs for something, e.g. applied at BC's or as initial conditions. Or you need to make them active, which you can do from the GUI under 'Tools -> Active Mixtures and Species'.

2. ESI-CFD: This is the default database that is provided with the installation. In the Database Manager, this is the data available under the "Database" folder (see figure 2). The database file is called "esi-ace.sdb" and is located in your installation directory in ACE_GUI_version\database. This database can be accessed by any simulation as long as the user is running the GUI from this installation directory. This database cannot be modified.

3. Local: This data is stored inside the "user-ace.sdb" file. This file can be placed anywhere, for example in C:\Documents and Settings\Combustion. To access this database, you need to specify its path from the GUI under 'Edit -> Preferences: User Files', as shown in figure 3 below. For new data (such as species) to be stored in this database, you need to create it under the "Database" folder. After creating the data, you will see that it has a "@" sign at the end of its name, indicating it is part of the "user-ace.sdb" (see figure 2).

   

   Figure 3.  Database path specification under 'Edit -> Preferences'

ESI-CFD and local data (from the "esi-ace.sdb" and "user-ace.sdb" files) are automatically loaded into the current DTF. Species, Mixtures, etc. can be copied to the local database by simply using the usual "right-click copy/paste" operation. Sub-folders can also be created in the local database (e.g. each project could get its own sub-folder).

How to share data

Sharing of material data can be achieved through the local database "user-ace.sdb". To do so, the local database can be located on a shared disk or server, to which users have access. Then, users must change the path defined under preferences to make it point to the shared "user-ace.sdb" file. As stated above, all data located in this file will have a "@" sign appended to the names.

Further tips about using shared material database

• To avoid confusion, the shared disk (server) should be mounted automatically after restarting the workstation, otherwise the user will not have access to the file (no error message will be given).
• The user should not use a "@" sign when defining a name, for example when defining for species or mixtures.
• Always use unique names for species, mixtures etc. This will make accessing the right entities simple.
• Reading the shared database at the same time is not a problem, but when a user is writing to it, other operations might not work.
• The shared file can be defined as read-only, if required.

If you have any questions about this topic or would like us to discuss other topics in the future, please let us know.

Regards,
Hans-W. Mindt
ESI CFD Support Team