Recent developments in diesel piston engine technology have increased performance in a very significant way. In this paper a new hybrid diesel-turbine engine is introduced and it is compared to up-to-date turboprops. The weak point of the common rail engine is the difficulty to obtain very fast injectors for large engines. Automotive injectors are available only for small power outputs. The problem was solved with a dual chambers piston with two injectors per cylinder. It is then possible to use off-the-shelf automotive common rail components even on very large diesel engines with benefits on combustion especially at medium low power level. The other more interesting advantage is a significant increase on crankshaft maximum speed and reduction of head mechanical stress. It is then possible to have smaller and more powerful turbodiesel and hybrid engines. Another advantage is the improved reliability of a dual injection system. The diesel – turbine hybrid power unit proposed in this paper combines the advantages of the turboprop/turbofan/turboshaft and piston turbo-diesel-prop / turbo-diesel-fan / turbodiesel engines. However, It should be clear than the automotive commercial common rail components should be treated to use jp4, jp8 and jet(A1) fuels and to fulfil aeronautical requirements.
AIRCRAFT PROPULSION SYSTEMS : A DIESEL HYBRID ENGINE
FRANCIA, DANIELA;PIANCASTELLI, LUCA
2008
Abstract
Recent developments in diesel piston engine technology have increased performance in a very significant way. In this paper a new hybrid diesel-turbine engine is introduced and it is compared to up-to-date turboprops. The weak point of the common rail engine is the difficulty to obtain very fast injectors for large engines. Automotive injectors are available only for small power outputs. The problem was solved with a dual chambers piston with two injectors per cylinder. It is then possible to use off-the-shelf automotive common rail components even on very large diesel engines with benefits on combustion especially at medium low power level. The other more interesting advantage is a significant increase on crankshaft maximum speed and reduction of head mechanical stress. It is then possible to have smaller and more powerful turbodiesel and hybrid engines. Another advantage is the improved reliability of a dual injection system. The diesel – turbine hybrid power unit proposed in this paper combines the advantages of the turboprop/turbofan/turboshaft and piston turbo-diesel-prop / turbo-diesel-fan / turbodiesel engines. However, It should be clear than the automotive commercial common rail components should be treated to use jp4, jp8 and jet(A1) fuels and to fulfil aeronautical requirements.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
