Metering Characteristics of a Closed Center Load – Sensing Proportional Control Valve

The investigation of the flow through the metering section of hydraulic components plays a fundamental role in the design and optimization processes. In this paper the flow through a closed center directional control valve for load –sensing application is studied by means of a multidimensional CFD approach.In the analysis, an open source fluid-dynamics code is used and both cavitation and turbulence are accounted for in the modeling. A cavitation model based on a barotropic equation of state and homogeneous equilibrium assumption, including gas absorption and dissolution in the liquid medium, is adopted and coupled to a two equation turbulence approach.Both direct and inverse flows through the metering section of the control valve are investigated, and the differences in terms of fluid – dynamics behavior are addressed In particular, the discharge coefficient, the recirculating regions, the flow acceleration angle and the pressure and velocity fields are investigated and compared.