I am running the gas exchange process of an engine using STAR-CD v3.26. I am able to create the geometry file. When I try to write the problem file, the error message 'error 28 transient data file is not connected' is printed.

what the error message means?

please connect the transient file and write the problem file You can type the following commands in output window

trfi,connect

geom

The output display is,

EVNT*>

trfi,connect

**ERROR - UNABLE TO READ FILE test.trns

IT MIGHT NOT BE A TRANSIENT HISTORY FILE - PLEASE CHECK

TRAN*>

If you are using es-ice for the engine mesh, try: evfi conn

Mepgzzi

The error message means your model file is configured for an advanced (i.e. multiple step) transient yet you have no transient file.

You can use the transient module to create the transient file. The transient module is through the pull down menus: Modules->Transient.

You can use the command "time,single" to switch back to a simple transient. This method does not require a transient file.

Thank you again Pauli.

When I make an empty transient file using module->transient, a problem file can be written.

In moving mesh case, what is the relation between the transient file and the event file? How do I create a proper transient file in this case?

In version 3.26, you don't really need the transient module. Enter the command "time, single" & you should no longer need a transient file.

The event & transient files are not related.