Performance Characteristics of Jet Fuel in Heavily Loaded Contacts

Abstract

Friction coefficient, bearing performance (i.e., torque generation and temperature rise), and rolling contact fatigue of steel and ceramic (silicon nitride) materials operating in the presence of JP-8+100 jet fuel and Mil-L-23699 turbo jet oil were investigated. A ball-on-disk test machine was used to measure the coefficient of friction of a steel ball on a steel disk operating under various loads and slide-to-roll ratios when lubricated with JP-8+100 jet fuel. The results indicate that the fuel provides an extremely low friction coefficient under the conditions considered in this investigation. A three-ball-on-rod rolling contact fatigue testing machine was used to determine the fatigue life for different combinations of materials (i.e., silicon nitride and steels) and lubricants. As expected, the Weibull analysis indicates that the rolling fatigue life operating in the presence of jet fuel was less than that of an oil-lubricated contact. A bearing test machine was also designed, developed, and used to obtain the friction (torque) and the temperature characteristics of bearings operating in jet fuel and oil. The result from the bearing rig indicates that the fuel has a lower generated torque and temperature rise than oil.