Stady of the thermal-oxidative stability of synthetic oils for aircraft gas turbine engines and helicopter gearboxes

Abstract

The aim of the research was to develop a method for determining the values of aviation oils during their oxidation based on the theories of chemical kinetics. Studies of the thermal-oxidative stability (TOS) of aviation lubricating oils based on polyesters for gas turbine engine aircraft were carried out using the method based on GOST 23797-79. The values of the kinematic viscosity at temperatures of 100 °C and minus 40 °C, as well as the acid number of samples of oils LZ-240, ASMO-200M, ASMO-220 and VASMO-225M, oxidized for 10, 20, 30, 40 and 50 hours at temperatures of 200, 225 and 240 °C were determined. Based on the results obtained, kinetic graph changes in oil parameters are constructed, the reaction order is determined, and models of changes in oil parameters during oxidation based on the Arrhenius equation and the Van't-Hoff rule are proposed. The calculation error does not exceed 10%. Dependencies of oxidation temperature and oxidation time are built, where maximum permissible values of oil parameters are achieved. These function allow you to evaluate the operability of oils and the quality margin according to its TOS.