JP-8+100: The Development of High-Thermal-Stability Jet Fuel

Abstract

Jet fuel requirements have evolved over the years as a balance of the demands placed by advanced aircraft performance (technological need), fuel cost (economic factors), and fuel availability (strategic factors). In a modern aircraft, the jet fuel not only provides the propulsive energy for flight, but also is the primary coolant for aircraft and engine subsystems. To meet the evolving challenge of improving the cooling potential of jet fuel while maintaining the current availability at a minimal price increase, the U.S. Air Force, industry, and academia have teamed to develop an additive package for JP-8 fuels. This paper describes the development of an additive package for JP-8, to produce “JP-8+100.” This new fuel offers a 55°C (100°F) increase in the bulk maximum temperature (from 325°F to 425°F) and improves the heat sink capability by 50 percent. Major advances made during the development of JP-8+100 fuel include the development of several new quantitative fuel analysis tests, a free radical theory of autooxidation, adaptation of new chemistry models to computational fluid dynamics programs, and a nonparametric statistical analysis to evaluate thermal stability. Hundreds of additives were tested for effectiveness, and a package of additives was then formulated for JP-8 fuel. This package has been tested for fuel system materials compatibility and general fuel applicability. To date, the flight testing has shown an improvement in thermal stability of JP-8 fuel. This improvement has resulted in a significant reduction in fuel-related maintenance costs and a threefold increase in mean time between fuel-related failures. In this manner, a novel high-thermal-stability jet fuel for the 21st century has been successfully developed.