Study of Interconnected Physical Processes in the Magnetic Fluid Sealer

Abstract

The purpose of this work is creation of an interconnected numerical model of the magnetic and hydrodynamic fields of the ferrofluid sealer to analyze the effect of centrifugal forces during shaft rotation on the retained pressure drop. The set goal was achieved by selection of the necessary equations, boundary conditions, assumptions and properties concerning the ferrofluids when building a numerical model of the sealer gap in the Comsol Multiphysics simulation environment. The important results of the work were the obtained and analyzed distributions of the magnetic field and pressure field in the ferrofluid, the evaluation results of the of the effect of centrifugal forces arising during the shaft rotation, on the pressure drop held by the sealer. It was shown that with a shaft radius of up to 50 mm and speed up to 3000 rpm, the change in the retained pressure drop was insignificant, and it was up to 2 % of the values with a stationary shaft. Significant manifestation of centrifugal force for the investigated shaft radii began at 6000 rpm. It was shown that the decrease in the retained pressure drop with an increase in the working gap was associated with the decrease in the magnetic field gradient. The significance of the results consisted in the possibility of using the developed model for the study of the ferrofluid sealer gap processes. Comparison with the data obtained using the analytical formulas showed that the latter overestimated the retained pressure drop