Session: 04-23 Ignition I

Paper Number: 126713

126713 - Ignition of Aged Lubricants in a Shock Tube 

Lubricants are employed to reduce friction and internal wear of gas turbines. Lubricant formulas are highly researched and are usually formulated with mineral oil and several additives to obtain optimal heat transfer and friction coefficient values. However, as gas turbines require higher temperatures for higher efficiencies, lubricants are being pushed to their limits, with coking, thermal degradation, and even combustion occurring for these lubricants. Typically, if a fire occurs, the gas turbine could experience a large amount of damage. Therefore, it is necessary to characterize a lubricant’s reactivity and understand the combustibility limits of these lubricants. There have been multiple papers from the authors’ group depicting the reactivity curves of some off-the-shelf lubricants. However, lubricants age with wear and heating cycles. This aging changes the physical attributes, in turn degrading the lubricant over time. This degradation has the potential to change the chemical composition, especially if coking and thermal degradation were to occur. As such, an analysis of this phenomenon on different aged lubricants is conducted. To characterize the reactivity, a shock-tube facility at Texas A&M University is utilized. The high-pressure shock tube (HPST) at the university is fitted with an automotive fuel injector which dispenses a set amount of oil ahead of the incident shock wave. The lubricant is vaporized by the incident shock wave, and ignition of the lubricant is observed using OH* chemiluminescence diagnostics after passage of the reflected shock wave. This type of measurement allows for better understanding of the differences in reactivity between newly opened lubricants and lubricants left exposed to an air environment. Additionally, such studies could result in a better understanding of the chemistry occurring in the aging process of lubricating oils. Overall, the ignition of several aged lubricants at high-temperature conditions was studied, and the results are presented in this paper.

Presenting Author: Matthew Abulail Texas A&M University

Presenting Author Biography: Matthew Abulail is a graduate assistant researcher at Texas A&M University. He completed his bachelor of science in mechanical engineering at Texas A&M University and is continuing his education towards a doctorate in mechanical engineering under Dr. Eric L Petersen.

Authors:

Matthew Abulail Texas A&M University
Raquel Juarez Texas A&M University
Eric L. Petersen Texas A&M University