Research and development of advanced high-temperature Air Force turbine engine oil (c)

Military and commercial jet aircraft engines operate more efficiently and h otter than in the past to increase fuel efficiency. Advanced structural eng ine materials permit hotter burning, more efficient engines. These trends w ill continue. Many current gas turbine engines are experiencing oil system coking and oth er problems related to the limited thermal and oxidative stability of the c onventional, ester-based gas turbine engine oils. The best current oils hav e a maximum operating temperature of about 200 degrees C. The authors initi ated a program to develop a new class of ester-based lubricants to meet the ir high-temperature requirements. The rat-get temperature range of this new oil is -40 degrees to 232 degrees C. Target requirements were established and communicated to industry. This paper presents those requirements and in itial results on the most promising candidates.