Increase engine efficiency and how? Pratt and Whitney to demonstrate the concept of “rotating engine detonation”

Pratt and Whitney, in collaboration with Raytheon Missiles & Defence and Raytheon Technologies Research Center, has secured a contract with the United States Air Force (USAF) to develop a ground test demonstration of a rotating engine detonation concept.

Representative | Defense Here

The value of the contract is undisclosed as of yet and the collaboration is aimed at developing an engine capable of supporting higher-Mach flight speeds.

Pratt & Whitney’s Gatorworks was able to complete initial concept development well ahead of schedule, and we will continue leveraging our digital and agile capabilities to accelerate progress on this program

says Dave Stagney, director of Gatorworks, Pratt’s prototyping arm

So, what is the concept all about?

Rotating detonation engine (RDE)

A conventional jet engine offsets massive spike(s) in temperature and pressure by allowing the volume of gas to expand as it’s sprayed or injected into the combustor. The resulting stream of combustion gases passes through the engine, spinning turbine blades as it exists.

Conventional jet engine | Wikimedia Commons

The entire working of an RDE revolves around a detonation wave that travels around a circular channel (annulus). Fuel and oxidizer are injected normally through small holes or slits.

An igniter is used to initiate the detonation in the fuel-oxidizer mixture. This releases the energy necessary to sustain the detonation. The combustion products expand out of the channel and are pushed out of the channel by the incoming fuel and oxidizer.

“A rotating detonation engine operates via a continuous detonation wave that propagates around the inside of a cylindrical combustor. Air and natural gas propellant (blue) are introduced continuously through the inlet and react across the detonation wave that is moving perpendicular to the incoming propellant. High-temperature, high-pressure products behind the detonation wave expand and exhaust out (top) to drive a turbine or generate thrust. Once the process begins, it self-sustains as long as the inlet propellant is flowing”. Credit: Staff research, Aerojet Rocketdyne

It is to be noted though, that the design of the combustor would be radically different- one that would release energy in a rapid, continuous succession of detonations set off by shockwaves rotating inside a cylindrical combustor.

Technically speaking, an RDE should slash specific fuel consumption by about 5% compared to a conventional engine. A rotating detonation engine would slash specific fuel consumption further.

Given the need for this critical engine technology, the Raytheon Technologies team will utilize its advanced resources and expertise to meet the technical objectives in an expeditious fashion. The engine is being designed to fly at higher Mach speeds which will enable and broaden future vehicle designs and applications and will be a key element of Pratt & Whitney’s high-speed engine portfolio to meet future customer requirements

says Gatorworks

Reportedly, technology is been increasingly seen as important for the future development of hypersonic vehicles.


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