Numerical study of solid particle erosion in hydraulic spool valves

The null characteristics of hydraulic spool valves change significantly due to solid particle erosion. In the present work, a numerical model has been established to predict the material removal rate and the worn profile evolution with erosion in hydraulic spool valves. The particle trajectories are solved by a stochastic separated flow model based on eddy interaction, and the squeeze film is included as a part of a particle-wall interaction model. The erosion rates are then predicted by the particle impact characteristics, and the worn profiles are obtained by a time-discrete and spatial-discrete update method. The major influencing factors, including particle size, differential pressure, spool opening, and flow direction, are discussed. Through comparison with laboratory experiments and a field case, the model was verified. The present model and theoretical analysis are intended to elucidate the life-cycle management, life evaluation and degradation-resistant design of the spool valve.