I am looking for a code that'd help me model overexpanded nozzles with separated flow. The issues to be evaluated are not only to characterize the separation regions but also to assess the flow characteristics several throat diameters downstream from the exhaust plane.

I'd be very appreciative if you could tell me which code(s) could do this job effectively. If the code is commercially available, please tell me who develops and markets it.

A paper report results obtained with a code identified as "USA CFD code" for Unified Solution Algorithm, but I cannot find out whether this code is commercial. Anybody knows anything about this USA code?

Thanks

The USA CFD code, to my knowledge, is a structured grid code developed at and owned by Boeing.

The USA code is unustructured and owned by Boeing. CFD++ is a commercially available code made by Metacomp Technology. It was made by the same developers as the USA code. It would certainly do what you need it to do.

You could inquire about the WIND code. One of its intended applications is nozzle flows. See the webpage

http://www.lerc.nasa.gov/www/wind