Fluid model for grease lubricants


Multiphase CFD flow model with dynamic oil bleeding behavior for grease lubricated rolling contacts

  grease lubricated rolling contact Copyright: © MSE


In the field of rolling bearings, more than 80% of the bearings are grease lubricated. These greases consist of a lubricating oil, addtives and a thickener, which stores the oil within its sponge-like structure. During operation, the oil bleeding can be observed, which ensures the lubrication of the tribological contacts. However, the understanding of this behavior is yet limited, due to the complex rheology of greases. In contrast to oil lubrication, the inhomogeneous multiphase fluid as a combination of oil and thickener components is not modelled yet. However, this multiphase nature must be considered to derive a reliable numerical model for predicting the service life and efficiency of grease lubricated rolling bearings.

Research objectives

Development of a computational fluid dynamics (CFD) model for greases with the subsequent sub-models

  • model for the grease distribution around the contact of a rolling contact by taking the rheological behavior into consideration
  • model for the bleeding behavior of greases with different porous microstructure and starved bleeding oil lubrication of a rolling contact
  • model for the mixed phases flow of bleeding oil and thickener layer in the contact of a rolling contact

Promoted by

China Scholarship Council-RWTH Aachen University Joint Program

Project sponsor

China Scholarship Council