Thermo Mechanical Systems Co
Turbo-Compound Engines
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TMS developed the gas
turbine portion of a 700 HP hybrid Diesel/Gas Turbine ("Giesel") engine for use
in future military vehicle applications. The gas turbine consists of the
8" diameter compressor and turbine spool shown on the left. The compressor achieved
an efficiency of 80% at a pressure ratio 5 to 1 and a turbine efficiency of 88%!
The gas turbine is designed to mechanically connect to the output shaft of a two-stroke diesel engine which in addition to being supercharged is enabled to double its output from 350 to 700 HP. In normal operation at low power, full advantage can be taken of the low specific fuel consumption of the diesel engine, while in dash mode advantage is taken of the low specific weight of the turbo compounded engine to substantially boost the power output.
In loiter mode with the combustor inactive, the gas turbine acts as a turbocharger for the diesel. In dash mode the combustor is fired up and power is added to the diesel by the power absorption turbine. Typical applications of Giesel engines include light armored personnel carriers. Current requirements are for much lighter, more agile armored fighting vehicles that are able to respond to a greater variety of tasks. At the same time endurance and range remain equally important. Hence, compression ignition internal combustion engines are favored for their fuel economy. To achieve the
desired agility and speed without exorbitant weight penalties,
a gas turbine with an output shaft connected to the engine is added which results in
a turbo compounded engine now referred to as a Giesel.
In the wake of 9/11, force mobility was brought into sharper focus and great emphasis has been placed on innovative defense responses to widely dispersed international threats. As result, the application of Giesel type power plants are expected to accelerate and to multiply beyond the use in wheeled vehicles. For instance, light tracked fighting vehicles seem natural candidates. The market for such power plants is global in scope and could be significant. |
The
gas turbine system includes a gas producer consisting of a compressor and
turbine on a common shaft and a combustor, and a
free turbine connected to the engine output shaft through a gearbox. The Giesel
is started by starting the gas turbine with compressed air and igniting the
combustor which brings the gas turbine up to idle speed, puts torque on the
engine crank shaft and heats up the intake manifold of the V6 two-stroke
diesel. The diesel can then be started to bring the whole power plant into
operation. 
