Research on the viscosity characteristics of water glycol hydraulic fluids in deep-sea environment from molecular dynamics.

The utilization of water glycol as a working medium represents a significant advancement in the realm of deep-sea hydraulic transmission systems. The viscosity of water glycol is a crucial parameter for hydrodynamic lubrication, yet it is profoundly influenced by the environmental conditions of the deep sea. This study employs the TIP4P/2005 water molecule model in conjunction with the optimized potentials for liquid simulations all-atom force field, and non-equilibrium molecular dynamics method to predict the viscosity of water glycol hydraulic fluids with varying compositions under deep-sea conditions. The simulation values agree well with the experimental results. Furthermore, this study introduces a fitting equation that accounts for the effects of composition, temperature, and pressure, enabling the prediction of the viscosity of water glycol hydraulic fluids within the 0–11 000 m sea water environment. [ABSTRACT FROM AUTHOR]