(Courtesy photo/AEDC) U.S. Air Force is developing an advanced high efficiency diesel engine, as a potential replacement for current ...
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| (Courtesy photo/AEDC) |
U.S. Air Force is developing an advanced high efficiency diesel engine, as a potential replacement for current manned and unmanned aircraft internal combustion engines.
The Air Force Research Laboratory Advanced Power Technology Office, along with Engineered Propulsion Systems and the Arnold Engineering and Development Center, recently concluded ground-based testing of the engine.
Designed by Engineered Propulsion Systems as part of an AFRL effort, the Graflight V-8, 4.3 liter engine is a “clean sheet” design specifically intended for aircraft use. It is liquid-cooled and capable of using either a composite or aluminum propeller.
The compact engine is built to use up to 40 percent less fuel than typical aircraft engines, with less vibration. This increased efficiency extends operational range and loiter time by up to 50 percent.
The one of the major advantage of the engine is its multi-fuel capability. Using a innovative control unit, the engine can run on diesel, Jet-A or military fuel JP-8 that are readily available in theatre. Hence it reduce the need to transport specialized fuels to operating bases, enabling operation from remote regions currently impractical.
Since the engine require considerably less fuel, it can extend reach of the aircraft or enable more weapon payload capability.
The first step in turning this innovative design into reality was proof-of-concept testing, beginning with the recent ground tests conducted at the Arnold Engineering Development Complex. Here, the development team performed simulated flights at altitude in the facility’s Propulsion Development T-11 Test Cell, which was reopened for this test effort after not being used for a decade. The T-11 test cell simulates airflow at a variety of altitudes.
During the ground testing, the EPS Graflight engine was taken through a range of operational flight conditions, from sea-level to 30,000 feet and back, successfully meeting performance expectations and generating valuable data on performance factors such as fuel consumption, calibration, vibration and power output.
Once the proof-of-concept is fully demonstrated, it will be considered for use in several Air Force manned platforms. Designers will also work to scale the engine down to a smaller variant, better sized for current Air Force unmanned aircraft.
