Guy Norris/LOS ANGELES
Eurojet partner ITP of Spain is planning to run vectored-thrust nozzle tests on an EJ200 engine developed for the Eurofighter EF2000 in early 1998. A first flight test could take place as early as 2000. ITP is already responsible for the nozzle on the basic EJ2000.
A thrust-vectoring EJ200 variant is one of several growth options being examined by Eurojet for the future. ITP is working with DASA, particularly because of its X-31 (thrust-vectoring, post-stall manoeuvring demonstrator) connection, says Rolls-Royce Military Aero Engines chief of advanced propulsion systems design, Stephen Morgan.
ITP, in which R-R has a 45% share, has set up a full-scale technology-demonstration programme for an axisymmetric thrust-vectoring nozzle for the engine. The nozzle is controlled by a novel arrangement of three concentric rings and the four standard EJ200 nozzle actuators.
The system fits within the current installation envelope and the nozzle provides the required pitch and vector control "as well as independent divergent petal exit area control", says Eurojet. The nozzle, is expected to be offered for the EF2000, as well as other airframes, such as the Saab JAS39 Gripen.
Retrofitting the engine to the EF2000 would present no problems, according to Morgan. The aft bulkheads of the production aircraft have been strengthened in anticipation of higher loads, and "-within the engine architecture, we're well placed to take care of it".
The vectoring nozzle would operate initially at the baseline EJ200 power levels of 60kN (13,500lb) maximum dry thrust, and 90kN with reheat. Optional growth plans cover taking power much higher by around 2010.
Eurojet's first growth step would raise normal power to about 72kN and combat power to above 103kN. Eurojet believes that this is feasible in 2000-7 by incorporating an updated low-pressure (LP) compressor, improved turbine cooling and materials.
The updated compressor would have a pressure ratio of 4.6 and a 10% increase in fan flow. "We're currently at [89kN] and, with Eurofighter in mind, the contract calls for a 15% increase in power. It's a straightforward step to 15% in the first phase," says Morgan, who adds that the fan change would be mainly a R-R responsibility, while MTU would upgrade the compressor.
The second phase of growth would follow in about 2010, taking dry thrust to around 78kN and combat power to nearly 120kN. This bigger step, would require a new LP system with a high-flow fan, a higher pressure ratio and a revised LP turbine. The core would also require "up-flowing".
The third EJ200-powered EF2000, the DA5, is due to be flown for the first time at Manching, Germany, in November, with the DA4 (the first UK-based EJ200-powered airframe) to fly in December. The DA1 and DA2 will have EJ200s in 1997.
Source: Flight International
