Rob
Ansys Employee

There's an inkjet printer tutorial somewhere, that may be an older one on the ALH or in Fluent's Help system. That's a pretty close match to a syringe.  I'd also question the need to model the piston and exiting liquid unless the back pressure on the needle alters the piston speed. 

Otherwise, have a look on ansys.com as we've (Fluent and then Ansys) run a range of webinars, seminars, blogs etc over the last 20 years or so.   Here's a starting point   https://research.rug.nl/en/publications/computational-modelling-for-dry-powder-inhalers  but consider how wide a range of applications there are too.