AC2T represented SITOLUB at 3rd TU Wien – NUAA Symposium

The partner AC2T research GmbH represented SITOLUB at 3rd TU Wien – Nanjing University of Aeronautics and Astronautics (NUAA) Symposium. The partner’s collaborators gave two talks around the field SITOLUB is emerged. Below is a summary of what was presented in each one of the talks.

 

Priv.-Doz. Dr. Stefan Eder from AC2T research GmbH recently showcased the EU-funded project “Simulation tools for the design of safe and sustainable lubricants” (SiToLub) during the 3rd TU Wien – Nanjing University of Aeronautics and Astronautics (NUAA) Symposium.
This innovative initiative, supported by Grant Agreement 101138807, aims to facilitate the European industry’s “Green and Digital” transition while aligning with the “Chemicals Strategy for Sustainability” (CSS).

 

Revolutionizing Lubricant Design SiToLub focuses on developing advanced computational models that assess alternative substances during the design phase, enabling the substitution of Substances of Concern (SoC). These models offer a comprehensive evaluation of safety ((eco)toxicity and biodegradability), sustainability (via life-cycle assessment, LCA), and functional performance. The project uniquely addresses:

 

The resulting virtual assessment platform will be integrated into the European Tribology Centre’s Open Innovation Test Bed (OITB), which specializes in tribological services, including material characterization, modeling, simulation, and database development.

The Role of AC2T research GmbH AC2T research GmbH plays a pivotal role in predicting base oil properties like viscosity and thermo-oxidative stability. The team also evaluates the performance of key lubricant additives, such as:

Using state-of-the-art tools like reactive Molecular Dynamics (rMD) and Finite Element Method (FEM) simulations, the team assesses performance from the molecular to the macroscopic scale. This approach supports efficiency optimization and lifetime prediction for mechanical components like journal bearings and gears.

Targeted Innovations in Lubricant Chemistry Initial use cases in the SiToLub project focus on finding SSbD alternatives to:

 

Bridging Molecular Insights with Macro-Scale Applications Dr. Eder highlighted the importance of integrating molecular-scale insights into macro-scale elastohydrodynamic lubrication (EHL) simulations. These models provide accurate predictions of viscosity’s dependence on temperature, pressure, and shear rate, which are critical for analyzing frictional losses across lubrication regimes, as described by the Stribeck curve.

The SiToLub project exemplifies how computational tools can drive sustainable innovation in the lubricant industry, paving the way for safer, more efficient, and environmentally responsible products.

Talk: Methodologies to Predict Viscosity via Molecular Dynamics

AC2T research GmbH researcher BSc. Hendrik Ehrich explained the (reactive) Molecular Dynamics ((r)MD) simulation concept for tribological systems and the broad range of obtainable result types comprising the evolution of temperature, pressure, prediction of lubricants’ viscosity and its impact on Coefficient of friction, as well as determination of chemical and tribochemical changes along a time-scale. 

In detailed, multiple approaches were showcased on how viscosity can be predicted from Equilibrium and Non-Equilibrium Molecular Dynamics ((N)EMD) simulations, focusing on their advantages and disadvantages, namely computational time demand, noise levels, accessibility of low shear rates, among other. Practical implementations related to MD workflow for viscosity prediction purpose were discussed, including appropriate potential selection, molecular structure representation approach, applied automated parametrization steps, randomization of initial states for better statistical representation to suppress any initial configuration influences, averaging approach to yield statistically valid values, etc. 

Preliminary results of quantified viscosities for the initially selected hydrocarbon structures of hexadecane, PAO4 and squalane were shown by implementing both EMD and NEMD simulations under NVT ensemble within bulk (not confined) and confined conditions (representing lubrication gap) with explicit and implicit boundaries (surfaces). It was emphasized that method fit to the system of interest must be ensured due to current computational limitations of individual methods.