Allison Engine has revealed plans to run a new powerplant core by the end of this year, which it hopes could provide the basis for a low cost "World Engine" family of turboshafts and turboprops in the 220-820kW (300-1,100shp) power range.
The emphasis is on affordability and low acquisition cost, as well as operation, says programme chief engineer Craig Heathco. The fundamental design is therefore based around technology for an advanced small industrial gas turbine, rather than the more exotic - and far more expensive - technology developed through US military research programmes such as the advanced turbine engine gas generator. "Our intention is to develop a core for use in industrial applications and then put a reduction gear on the same core," says Heathco.
Rolls-Royce-owned Allison is talking to airframe manufacturers "to come up with a fairly definitive set of requirements for turboprop and turboshaft models", he adds. "Once that is settled, our initial offering will probably be in the 750-850shp range, with subsequent growth to 1,100shp."
The engine will provide a 21st century replacement for the Allison 250, and is expected to be developed in two sizes.
"The majority of the thrust is to have world class performance, but, having achieved that, most of the effort will be on making it low cost, and the industrial application isn't inconsistent with that," he adds. The industrial core - aimed at a 500kW generator - will lead the programme, which will then be certificated for follow-on aerospace applications.
Technology likely to feature in both includes a low emissions combustor and a conventional axial turbine using high temperature resistant materials. The extensive use of ceramic materials is also planned, says Heathco. The compressor is expected to borrow features from a two stage axi-centrifugal design developed under the Expendable Turbine Engine Gas Generator effort with NASA Lewis.
Source: Flight International
