Garrett TPF351
The Garrett TPF351 is a turboprop engine designed by Garrett Engine Division of AlliedSignal Aerospace Company. Initiated by Garrett in October 1987, the TPF351-20 engine was selected by Embraer to power the Embraer/FMA CBA 123 Vector, a high-speed commuter "pusher" aircraft. It was first tested on May 19, 1989 and then ground tested and flight tested on a Boeing 720 in July 1990. The first prototype CBA123 was tested in July 1990, followed by a flight to the Farnborough Air Show in September of the same year.[1] Both programs were cancelled in 1994.
| TPF351 | |
|---|---|
 | |
| Type | Turboprop |
| National origin | United States |
| Manufacturer | Garrett Engine Division of AlliedSignal Aerospace |
| First run | May 19, 1989 |
| Major applications | Embraer/FMA CBA 123 Vector |
| Developed from | Garrett TPE331 |
Design
It was built on the 1,310 kW (1,760 hp) TPE331-14 which power the Jetstream 41, keeping its combustor system and high pressure turbine, already of the right size. The two-stage centrifugal compressor is scaled-up from the Garrett F109 turbofan of the Fairchild T-46 and Promavia Jet Squalus trainers. It was Garrett's first free-turbine turboshaft, avoiding the high reduction gear of a single spool turboprop and allowing an easier starting since the gas generator is disengaged from the power turbine. The HP spool turns at 31,500 rpm while the LP spool turns at 19,444, reduced to 1,700 for the propeller: a 11.4 reduction ratio. Power can grow by 25% within the same size.[2]
It is assembled from six modules : accessory gearbox, compressor, combustor, gas-generator turbine, power turbine and propeller gearbox. The FADEC provides torque-limiting protection, propeller synchronization, auto-propeller feathering and auto-relight. It could have powered growth versions of the Beech Starship or Piaggio Avanti. A large-diameter bore hole running through the compressor and turbines allow a concentric shaft to connect the power turbine to a front-mounted gearbox to convert it to a tractor configuration. [2]
Applications
Specifications (TPF351-20)
Data from Flight International, 28 November 1990[2]
General characteristics
- Type: Turboprop
- Length:
- Diameter:
- Dry weight: 363kg / 800lb with all accessories
Components
- Compressor: two-stage centrifugal
- Combustors: reverse-flow annular combustor
- Turbine: two-stage axial HP turbine, three-stage axial power turbine
Performance
- Maximum power output: 1,120 kW (1,500 hp) gearbox, 1,570 kW (2,110 hp) thermodynamic
- Overall pressure ratio: 14:1[3]
- Specific fuel consumption: 0.495 lb/hp/h (301 g/kW/h) in cruise[3]
- Thrust-to-weight ratio: 3.09 kW/kg (1.88 hp/lb)
See also
Related development
Comparable engines
Related lists
References
- Miller, R. (1 April 1991). "Garrett TPF351-20 Engine Flight Test and Ground Test Performance". SAE Technical Paper.
- "Vector pushes ahead with TPF351". Flight International. 28 November 1990.
- Mark Lambert (May 1988). "TPF351-20, the Garrett free turbine turboprop". Interavia. p. 484.