Evaluation of Fouling Propensity of Aviation Lubricants Using the High Temperature Deposition Test
THE HIGH-TEMPERATURE DEPOSITION TEST (HTDT) METHOD IS DESIGNED TO EVALUATE THE DEPOSITION AND DEGRADATION CHARACTERISTICS OF TURBINE LUBRICANTS WHEN STRESSED UNDER MIXED-PHASE FLOW CONDITIONS FOUND IN CERTAIN PARTS OF AVIATION GAS TURBINE ENGINES. THIS METHOD IS APPLICABLE TO LUBRICANTS THAT FORM DEPOSITS IN THE RANGE OF 0.1 TO 100 MG DURING THE COURSE OF A TEST.
Rationale: Aviation turbine lubricants are exposed to mixed-phase and dynamic temperature conditions during use. Many bench and laboratory tests used to characterize the oxidative stability or fouling properties of a lubricant are either static temperature tests or circulate the sample as a single, liquid phase. The HTDT exposes the lubricant to mixed phase conditions, comingling humidified air and lubricant within the test loop.