F-15 engine tested on tri-fuel blend

[ErnstBlofeld]

Defense Talk:

Continuing the march toward certifying the entire Air Force fleet on alternative fuels, an F-15 Eagle engine is undergoing performance testing here using a unique blend of three different fuel types.

The F100 engine is being tested with a combination of JP-8 conventional aviation fuel; a biofuel derived from tallow, which is an animal fat; and a synthetic fuel derived from coal through a process commonly known as Fisher-Tropsch.

The fuels testing is being conducted to ensure the different fuels, in varying combinations, are suitable for an upcoming series of F-15 flight tests tentatively scheduled for October at Eglin Air Force Base, Fla., said Brian Knack, the Aerospace Testing Alliance's program engineer for the test. ATA is the operating contractor at the Arnold Engineering Development Center.

"This (first phase of the test) evaluated a 50 percent (by volume) tallow-derived fuel, while the final phase is bringing Fischer-Tropsch-derived fuel together with the bio-fuel forming yet another new and unique blend," he said.

Testing has simulated the overall engine conditions experienced at near sea-level conditions.

A baseline test using JP-8 was performed in the first phase of the test program. Then, a blend of 50 percent tallow-derived fuel and 50 percent JP-8 was evaluated. Finally, a blend of 25 percent tallow-derived fuel and 25 percent synthetic fuel and 50 percent JP-8 was evaluated.

"They've engineered these alternative fuel blends, both the tallow and FT, to meet the existing JP-8 (specifications) requirements," Mr. Knack said. "So, we're just verifying that, although it's within the same specification chemically, that it doesn't adversely affect engine performance."

Edited September 23, 2010 by Rheo
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