posted on Mar, 31 2016 @ 10:46 PM
A C-17 from Joint Base Lewis-McChord has been at Edwards testing drag reduction methods. The C-17 is a very costly aircraft in terms of fuel
consumption, so the Air Force is looking at different ways to reduce the drag, and save even a few percentage points of fuel consumption with them. A
couple percent fuel consumption reduction could save several million dollars over the course of a year. In 2012, the C-130, C-5, and C-17 used 70% of
the fuel purchased, with the C-17 being the highest of the three.
The first test, which was completed in March, involved removing the double strakes under the aft fuselage, and replacing them with three Vortex
Control Technologies Finlets on either side of the fuselage, to see how they perform compared to the strakes. The next phase, will increase the
number of Finlets to 16, by adding 5 more on each side of the aircraft. The third phase, will remove the Finlets, and add six microvanes instead.
The microvanes are small plastic blade shaped protrusions. The fourth and final phase will see fairings attached on the wings near the engines and
winglets.
After completion of the testing, this October, the data will be sent to the AFRL at Wright-Patterson to determine which, if any, of the modifications
reduce drag, and by how much. If any of them reduce drag, while not impacting the current capabilities of the aircraft, we may see them added on in
place of the strakes in coming years.
From testing synthetic biofuels to "vortex surfing," Edwards AFB is on the forefront of finding new ways to cut fuel costs for the Air
Force.
The latest venture is currently underway at the 418th Flight Test Squadron where a test team of Air Force and Boeing personnel has just completed the
first phase of Air Force Research Laboratory's C-17 Drag Reduction Program.
According to an AFRL study, the price the U.S. Air Force pays for jet fuel has quadrupled between 2004 and 2012. At the same time, the demand for
personnel and equipment to be transported around the world has increased. Airlifters like the C-130, C-17 and C-5, use most of the Air Force's fuel;
70% in 2012. Of these cargo planes, the C-17 uses the most fuel.
The purpose of the C-17 Drag Reduction Program is to collect data on how airflow is effected with different modifications done to a C-17 Globemaster
III.
www.edwards.af.mil...
C-17 standard configuration with strakes:
With both Finlets and strakes, testing aerodynamics:
With strakes removed and Finlets added: