Hydraulic Free Piston Engine

[exclaimedleech8]

A free piston engine is essentially a turbocharged engine in reverse. Rather than having a turbine provide compressed air to a piston engine, the free piston uses a piston engine to provide compressed air to a turbine.

The big advantage over a gas turbine was that the compressor would produce relatively cool air that meant the free turbine didn't need to be made from expensive super alloys while at the same time offering major efficiency advantages over normal crankshaft driven engines

In the 50s, there was even talk of free piston automobiles with GM and Ford developing prototypes. But according to one source, "starting, lubrication, and control issues were found to be insurmountable"

The engine found some success in marine applications. Junkers made free-piston compressors that were used in submarines and the oil tanker Morar was fitted with one.

It was also used in various stationary applications in Corsica, Sicily, and Singapore.

 

[publiusr]

Engine double? as a wingbox with turbine in the empennage?

By the engine not being in exposed nacelles it might be easier to keep warm. Turbine winds up with airflow and generates power maybe.

 

[exclaimedleech8]

By the engine not being in exposed nacelles it might be easier to keep warm. Turbine winds up with airflow and generates power maybe.

If you're cold, they're cold, bring your engines inside