Instituto Tecnológico da Aeronáutica, Praça Marechal Eduardo Gomes, 50, 12228-900 São José dos Campos, SP, Brazil.
An Acad Bras Cienc. 2024 Sep 9;96(suppl 1):e20240040. doi: 10.1590/0001-3765202420240040. eCollection 2024.
Currently, it is crucial for the lubricant formulation industry to explore cost-effective and environmentally friendly methodologies for analyzing the tribological properties of engine aviation lubricants under high-temperature and high-pressure operating conditions. This study demonstrates the feasibility of employing molecular dynamic simulations to gain essential insights into the evolution of the tribological properties of lubricants during operation. A three-layer molecular model was devised, comprising nickel aluminide molecules in the top and bottom layers, and polyol ester in the core. The impact of sliding velocities ranging from 20 km/h to 100 km/h was investigated under varying temperature and pressure conditions. Concentration, temperature and velocity profiles, radial distribution function, mean square displacement, and friction coefficient were calculated and analyzed in detail. Notably, the highest friction coefficients - ranging from 2.5 to 0.75 - were observed at the lowest temperature and pressure conditions tested. Conversely, other sections of the gas turbine exhibited substantially lower friction coefficients - ranging from 0 to 0.01.Simulations demonstrate that increasing pressure and temperature reduce polymer chain mobility, leading to stronger internal interactions within the lubricant. Consequently, lubricant adsorption onto metal surfaces decreases. Furthermore, the lubricant performs exceptionally well when its molecules encounter higher velocities and temperatures. Based on the results obtained, the research demonstrates that the presented technique provides both quantitative and qualitative tribological information essential for understanding a system molecular behavior, serving as a guiding framework for researchers in the field.
目前，对于润滑剂配方行业来说，探索具有成本效益和环保的方法来分析发动机航空润滑剂在高温高压工作条件下的摩擦学性能至关重要。本研究展示了使用分子动力学模拟来深入了解润滑剂在运行过程中摩擦学性能演变的可行性。设计了一个三层分子模型，顶部和底部层为镍铝合金分子，核心为多元醇酯。研究了在不同温度和压力条件下，滑动速度从 20km/h 到 100km/h 的影响。详细计算和分析了浓度、温度和速度分布、径向分布函数、均方根位移和摩擦系数。值得注意的是，在测试的最低温度和压力条件下，观察到最高摩擦系数为 2.5 到 0.75。相反，燃气轮机的其他部分表现出低得多的摩擦系数，范围从 0 到 0.01。模拟表明，压力和温度的增加会降低聚合物链的流动性，从而导致润滑剂内部相互作用增强。因此，润滑剂在金属表面上的吸附减少。此外，当润滑剂分子遇到更高的速度和温度时，它的表现非常出色。根据所得到的结果，研究表明，所提出的技术提供了对于理解系统分子行为至关重要的定量和定性摩擦学信息，为该领域的研究人员提供了指导框架。
