Pratt & Whitney tests three-stream engine to power military combat aircraft


Pratt and Whitney has tested a three-stream engine architecture for potential use in military combat aircraft.

The three-stream fan has an F135 core, which was tested as part of the US Air Force (USAF) Research Laboratory's Adaptive Engine Technology Development (AETD) programme.

Conducted at the Arnold Engineering Development Complex at Arnold Air Force Base in Tennessee, US, the testing demonstrates Pratt and Whitney’s ability to transition adaptive engine technology to meet future USAF requirements for combat aircraft propulsion.

Pratt and Whitney Military Engines president Matthew Bromberg said: "Preliminary data from the test indicates our three-stream fan has met or exceeded expectations with respect to performance, as well as the integrity of the turbofan machinery and fan module.

"This is an important milestone on the path toward the advancement and maturation of a next-generation adaptive engine, which will enable the warfighter to stay well ahead of future and emerging threats."

The modern military turbofan engines have two airstreams, including one that passes through the core of the engine and another that bypasses the core.

"This is an important milestone on the path toward the advancement and maturation of a next-generation adaptive engine."

The addition of a third stream is believed to provide an extra source of air flow to improve propulsive efficiency and lower fuel burn, or to deliver additional air flow.

Using a three-stream engine, the fighter jet can access an on-demand increase in thrust or smoothly shift to highly efficient operations when cruising.

This capability is expected to provide an optimal balance for combat scenarios requiring both high-end acceleration and increased range.

Pratt and Whitney will also conduct additional adaptive engine testing on a new high-efficiency engine core developed under the AETD programme later this year.

The company is said to be the sole provider of fifth-generation fighter engines such as the F119 and F135, which power the F-22 Raptor and F-35 Lightning II, respectively.