Hello Lydia,
Thank you for your reply. I designed my structure in the Patran software and imported that structure into the ANSYS workbench but creating the enclosure or fluid domain seems to be difficult. I am attaching the screenshot here. Could you please help me to create the fluid domain or enclosure? If I am trying to use an automatic method for external flow, it is showing some hints but I don't know the location of explore stage. 
You are navigating away from the AIS Discovery experience