Pratt & Whitney Canada's PW810 engine for the Cessna Citation Columbus business jet will share the same all-axial core as the Geared Turbofan that parent company Pratt & Whitney has been selected to provide for the Mitsubishi Regional Jet.
The commonality is part of P&W's new product family strategy, under which the company will develop advanced turbofans for business aircraft and GTFs for regional jets and single-aisle airliners.
As business jets fly higher and faster, they are not suited to the ultra-high-bypass GTF, says Alain Bellemare, executive vice-president, strategy and development at Pratt & Whitney.
Because of its greater experience with all-axial engines, US-based P&W will lead development of the core - high-pressure compressor, low-emissions combustor and high-pressure turbine - for both the 10,000lb (44.5kN) thrust-class PW810 and the 14,000-17,000lb-thrust GTF for the MRJ, says Bellemare, who is also president of P&WC.
The PW800 family, designed to cover the 10,000-20,000lb thrust range, will be the biggest engines yet developed by the Canadian company. Scaled-up versions of the turbofan would use the core from larger GTFs, such as the 23,000lb-thrust engine selected to power the Bombardier CSeries airliner.
The PW810 will be rated at 8,830lb thrust on the Columbus large-cabin business jet, and Bellemare says P&WC looked at offering a growth version of its 8,000lb-thrust PW308 instead.
Like other P&WC engines, the PW300 has a centrifugal compressor, which offers high efficiency in a compact space.
"Beyond, 8,000lb, centrifugal gets too loaded and it starts affecting life and growth," says Bellemare.
"We could have met the Columbus requirement by growing the PW300, but it would have compromised performance and life - more compromise than going all-axial. We decided it was not the optimum solution."
Two of P&WC's competitors in the "10K" engine market use centrifugal compressors: the Honeywell HTF10000 and Snecma Silvercrest, both of which have yet to find applications.
Another, the Rolls-Royce RB282 selected to power Dassault's future super mid-size Falcon, is an all-axial engine.
Source: FlightGlobal.com
