Master Thesis: Replenishment effects of grease lubricated rolling contacts

Webseite Institut für Maschinenelemente und Systementwicklung

The Institute of Machine Elements and System Engineering researches the fundamental structural and tribological behaviour of machine elements and represents them in experimentally validated model descriptions. These model descriptions are used to analyse and design the functional, loss and noise behaviour of entire technical systems with a focus on drive technology. The developed models are also used to research and develop methods of Model Based Systems Engineering as a central element of future inductive product development processes.

Greases, as a typically lubricant used for wind turbines drivetrain, consist of a thickener, which stores the oil within its sponge-like structure. During operation, oil is slowly released, which is referred to oil bleeding. This ensures an efficient operation with long service life for rolling element bearings. However, current models give an underestimated film thickness under starved condition. Therefore, the objective of the work is to evaluate the film thickness of a grease lubricated contact by simplifying it as an EHL contact with replenishment. This work will be carried out based on current starved EHL lubrication model within the framework of OpenFOAM. In addition, lubrication film thickness will be evaluated and compared with the previous theoretical and experimental results for validation.


  • Literature research on replenishment model of grease lubrication
  • Development of a cyclic boundary condition for rolling contacts
  • Evaluation film thickness using current model within simulation tool OpenFOAM
  • Validation the results theoretically and experimentally


  • Independent and reliable working
  • Interest and open mind to learn new things
  • Previous knowledge of programming or Computational Fluid Dynamics or tribology is an advantage, but not mandatory

We offer:

  • Intensive supervision
  • Immediate start or by appointment
  • Excellent working atmosphere
  • Suitbale for homeoffice
  • Promising topic and experience for a future career


We look forward to your application by email:

Shuo Zhang, M. Eng.
Institute for Machine Elements and Systems Engineering

Schinkelstraße 10, 52062 Aachen


Um sich für diesen Job zu bewerben, sende deine Unterlagen per E-Mail an