US Air Force to develop revolutionary jet engine

Wright-Patterson Air Force Base, Ohio, USA: Air Force Research Laboratory (AFRL) engineers have outlined a five-year programme to develop a new, adaptive engine that will enable pilots to switch from high-speed combat maneuvers to long-range persistence mode effortlessly. The programme is intended to overcome a fixed paradigm, under which today's jet engines operate - they can either provide fuel efficiency or high performance.

The AFRL's Propulsion Directorate recently issued a Broad Agency Announcement calling for the development of a demonstration programme for the revolutionary engine, called Adaptive Versatile Engine Technology, or ADVENT.

Under Project ADVENT, the aim is to develop inlet, engine and exhaust technologies that optimize propulsion system performance over a broad range of altitude and speed.

In August this year, under Phase I of the programme, the AFRL will select two competitive contractor teams who will be involved in a concept exploration phase. The remainder of Phase I will include critical component testing and preliminary engine design.

A single contractor, who will be selected in late 2009, will carry out the Phase II work. This phase will cover work from engine-detailed design through Technology Readiness Level 6, which signifies that the engine is ready for a full-up, operational test in a relevant engine environment. According to AFRL programme managers, demonstrator testing would occur in 2012.

According to AFRL engineers, this transformational engine is needed to combine speed, maneuverability, range and endurance.

"The ADVENT program represents the next big step in turbine engine technology development," Jeff Stricker, the chief engineer of the propulsion directorate's turbine engine division said. "It holds the potential to provide dramatic new aircraft capabilities that place high value on persistence, range, and speed combined with sensors, weapons and communications that demand higher power extraction from the engine."

Modern turbine engines are designed to operate optimally at a single flight condition, and are compromised at other mission points, Stricker said. Currently pilots must use the throttle to match thrust when conditions are not optimal. This results in diminished fuel efficiency and performance.

"ADVENT is a multi-design point engine that incorporates the best characteristics of high performance and fuel efficient jet engines into a single adaptable engine," Stricker said.

The new engine design will use adaptive fans and cores to generate high thrust when needed, and optimize fuel efficiency when cruising or loitering. If ADVENT fructifies, then future engine systems will be able to combine loiter with supersonic dash, provide short takeoff and landing combined with long range for mobility aircraft, improve combat maneuverability, and enhance thermal management.

Project ADVENT is a flagship effort under the Versatile, Affordable Advanced Turbine Engines Program, or VAATE. Managed by the Propulsion Directorate, VAATE is a national program aimed at advancing the state of the art in turbine engine technology.