Has there ever been a centrifugal turbine in an aircraft engine? These days, most jet engines feature axial compressors and turbines. However, there are some older aircraft engines with centrifugal compressors, like the Rolls Royce Nene. But I've never heard of any engine with a centrifugal turbine (radial flow turbine).
Does such a thing exist? Has one ever been built, tested, and flown? I'm interested in turboprops, turbojets, turbofans, even very tiny ones for RC aircraft.
Edit: Okay a radial flow turbine will not produce much of a jet of thrust, so I guess the only possible engine for this would be a turboprop. Edit 2: Not necessarily, a centrifugal compressor can redirect air outwards to another path, then downwards into a centrifugal turbine, which redirects it back to axial direction after all.
The Heinkel Hes 3b, which powered the Heinkel He 178, had a radial turbine. This was the first operational jet engine to power an airplane.