Euler–Lagrange CFD simulation and experiments on accumulation and resuspension of particles in hydraulic reservoirs

Abstract

Clean hydraulic oil is a major requirement for hydraulic systems. Hydraulic reservoirs are mostly considered as a storage of fluid but must fulfil more requirements. The hydraulic reservoir ensures the separation of gaseous, liquid and solid contaminations and has a big influence on temperature management. Thus, it is a major component to seize the accurate function of hydraulic systems. Fluid contaminations lead to increased wear of mechanical components, noise, technical failures, bad repeatability and fluid degradation. Therefore, smart designs of hydraulic reservoirs can reduce machine downtime and maintenance costs. This paper focusses on the particle size-dependent behaviour of solid contamination in hydraulic reservoirs, more precisely, on a CFD method to predict particle behaviour and the development of an experimental procedure to verify the model. The experiments and multiphase CFD simulations were carried out to investigate particle trajectories, their sedimentation and resuspension progress and to determine the accumulation areas. Lagrangian particle tracking determines these local deposition distributions over the whole typical flow range in hydraulic reservoirs for different particle sizes. To compare the CFD simulations and experiments, the simulation results are weighted by particle size density distributions. This study shows the possibility, to identify particle accumulation areas and particle (re-)sedimentation percentages with good accuracy, using Euler–Lagrange CFD simulation.