Publication

Abstract : This research explores the rheological properties of calcium hydroxide-based greases through experimental analysis and mathematical modelling. The Carreau–Yasuda model, commonly employed for the description of non-Newtonian fluids, is extended to include temperature dependency by means of the Arrhenius equation. The inclusion of temperature as a parameter in the model increases its predictive ability, allowing for improved viscosity estimates under different operational conditions. Shear-thinning behaviour of all grease samples tested is verified experimentally, while their elastic properties are confirmed by Carreau–Yasuda model (n < 0.5). Structural shear damage and limiting shear values were compared at varying temperatures, which showed considerable differences in grease performance. The enhanced model shows better accuracy in forecasting viscosity variation with thermal fluctuations, which makes it especially valuable for applications where there is a need for accurate lubrication control, like in the automotive and heavy machinery sectors. The minimal differences between experimental and calculated outcomes underscore practical aspects such as contaminants and material flaws, which conventional models cannot accurately model. These improvements will further enhance grease formulation and maximize lubrication performance, and temperature-dependent viscosity modelling will be an important tool in tribology and engineering applications.