Garrett TPF351
{{Short description|1980s American turboprop engine}}
| {{Infobox Aircraft Begin
|name= TPF351 |image= Garrett TPF351.jpg |caption= }} {{Infobox Aircraft Engine |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 |number built = |program cost = |unit cost = |developed from = Garrett TPE331 |variants with their own articles = |developed into = }} |
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 on July 9, 1990. The first prototype CBA 123 was tested on July 18, 1990, followed by a flight to the Farnborough Air Show in September of the same year.{{cite news |url= http://www.sae.org/technical/papers/911011 |title= Garrett TPF351-20 Engine Flight Test and Ground Test Performance |date= 1 April 1991 |author= Miller, R. |work= SAE Technical Paper }} Both programs were cancelled in 1992, when the TPF351 was nine months from engine certification.{{harvnb|Leyes|Fleming|1999|p=[{{GBurl|V0SnFt8JGokC|p=711}} 711]}}
Design
It was built on the {{cvt|1310|kW}} 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.
The engine ran about {{cvt|60|F-change}} hotter than the TPE331-14 in the core.{{harvnb|Leyes|Fleming|1999|p=[{{GBurl|V0SnFt8JGokC|p=710}} 710]}}
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 {{#expr:19444/1700round1}} reduction ratio.
Power can grow by 25% within the same size.
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.{{cite magazine |url= https://www.flightglobal.com/pdfarchive/view/1990/1990%20-%201668.html |title= Vector pushes ahead with TPF351 |magazine= Flight International |date= 28 November 1990}}
The engine was originally called the TPE331-16, but by 1988 it was renamed to the TPF351-20.{{cite magazine |magazine=Airline Executive |issn=0278-6702 |title=Garrett engine is redesignated |url=https://archive.org/details/sim_airline-executive-international_1988-02_12_2/page/n13 |department=Regional Airline Report |publication-date=February 1988 |page=12}} The "TPF" represented "Turbine PropFan",{{cite magazine |magazine=Airline Executive |issn=0278-6702 |title=Embraer unveils Time Machine |url=https://archive.org/details/sim_airline-executive-international_1989-07_13_7/page/15 |department=Regional Airline Report |publication-date=July 1989 |page=15}} while the -20 suffix indicated the {{cvt|2,000|shp}} nominal thermodynamic power rating.
Applications
Specifications (TPF351-20)
{{jetspecs
|ref=Flight International, 28 November 1990
|type=Turboprop
|length={{cvt|6.39|ft}}{{cite magazine |magazine=Flight International |issn=0015-3710 |title=Small-turbine directory |first=Simon |last=Elliott |publication-date=November 11, 1992 |volume=142 |number=4344 |id={{Gale|A12900382}} |pages=39+}}
|weight= {{cvt|800|lb|kg|0}} with all accessories
|compressor= Two-stage centrifugal compressor
|combustion= Reverse-flow annular combustor
|turbine= Two-stage high-pressure axial turbine, three-stage free-power axial turbine
|fueltype=
|oilsystem=
|power= {{cvt|1120|kW|order=flip}} reduction gearbox, {{cvt|1570|kW|order=flip}} thermodynamic
|thrust=
|compression=14:1{{cite magazine |title= TPF351-20, the Garrett free turbine turboprop |first= Mark |last= Lambert |issn= 0020-5168 |magazine= Interavia |date= May 1988 |page= 484}}
|bypass=
|aircon=
|turbinetemp=
|fuelcon=
|specfuelcon={{cvt|0.495|lb/hph|g/kWh}} in cruise
|power/weight=
|thrust/weight= {{cvt|{{#expr:1120/363round2}}|kW/kg|order=flip}}
}}
See also
{{Aircontent
|related=
|similar engines=
|lists=
|see also=
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References
{{reflist}}
Bibliography
{{Commons category}}
- {{cite book |title=The history of North American small gas turbine aircraft engines |url={{GBurl|V0SnFt8JGokC|pg=frontcover}} |given1=Richard A., II |surname1=Leyes |given2=William A. |surname2=Fleming |year=1999 |publisher=National Air and Space Museum and American Institute of Aeronautics and Astronautics (AIAA) |location=Reston, VA |isbn=1-56347-332-1 |oclc=247550535}}
{{Garrett/Honeywell aeroengines}}
{{USAF gas turbine engines}}