NASA has awarded a new round of contracts under its Ultra Efficient Engine Technology (UEET) programme, intended to develop more environmentally friendly powerplants.

The contracts are part of a five-year, $197 million procurement effort launched by NASA's Glenn Research Center in Cleveland, Ohio. More than half the money will be spent on aircraft engine technology and the rest on space vehicle propulsion.

The UEET programme is tackling local air-quality concerns by developing technologies to reduce nitrogen oxides (NOx) emissions by 70%. Aiming to minimise the climate impact of long-term aviation growth, the project aims to cut carbon dioxide emissions by 8-15%, by reducing fuel consumption 35% for large subsonic transports and 20% for high-speed or small subsonic aircraft.

Last year, the programme demonstrated greater than 70% reductions in NOx emissions in flametube tests, the first in a series of hardware evaluations leading to full-scale engine demonstrations. The flametube tests evaluated three multipoint lean direct injection combustion concepts, each of which achieved NOx reductions above the UEET goals.

Other technologies being developed under UEET include fan-blade trailing-edge blowing. This reduces fan rotor/stator spacing and improves wake mixing, which increases efficiency and reduces weight and noise. New composite fan-containment structural concepts are being developed under a separate programme.

Baseline vehicles for the UEET effort are 300-passenger subsonic and supersonic transports, a 50-seat regional jet and a 10-passenger supersonic business jet. NASA has been asked to extend its analysis work to include the Blended Wing Body aircraft, Boeing's C-17 transport, a general aviation aircraft and an unmanned air vehicle.

The latest awards, including work under NASA's Propulsion and Power and Advanced Space Transportation programmes, went to 11 companies including Aerojet, Boeing, General Electric, Honeywell, Lockheed Martin, Pratt &Whitney, Rolls-Royce and Williams International.

The contracts cover eight technology areas, including air-breathing engines, propulsion/airframe integration and auxiliary power systems. Further work will be performed on pulse-detonation engine technologies as well as turbine-based and rocket-based combined cycle powerplants. Pulse-detonation engines show promise as low-cost powerplants for high-speed aircraft.

Source: Flight International