create 3d code of nozzle

hello can you know how to create the 3d code of nozzle in c++?

Can you explain what you want in more detail? What type of nozzle?

What information do you want, the geometry, the flow rates?

I need create a code who compute radial nozzle . I got the geometry and want compute flow through the nozzle .

I also waiting for the answer of the question.....