Normal viscous force of pendular liquid bridge between two relatively moving particles.

In this work, Direct Numerical Simulations (DNS) of a pendular liquid bridge formed between two relatively moving particles are performed to evaluate the normal component of the viscous force exerted on the particles. The viscous force obtained are non-dimensionalised in order to clarify the parameters which can affect the dimensionless force. The DNS results are compared with the viscous force models in literature which are commonly used in DEM simulations. It is found that these models cannot be used with large inter-particle separation distance. A new and more accurate viscous force model is proposed from the DNS results which can be directly implemented in the DEM framework.