Increased-accuracy simulations and tests of flow characteristics in plastic hydraulic valves for precise control of fluid flow

Pressure drops on the working fluid flow control valves in hydraulic drive systems have a decisive impact on high-precision control of hydraulic receivers. The flow rate-dependent characteristics of pressure drop can be used to make informed decisions on the shape of poppet-seat pairs and to improve the operating parameters of the drive system. This fact is of particular importance in the designing of new hydraulic valves which can be manufactured with the use of modern manufacturing technologies (e.g. additive manufacturing). This article presents the results of CFD simulations of hydraulic oil flow through the flow-control valve, verified in experimental tests on a test stand. The tests focus on the flow through small control gaps, within the lift range from 0.25 to 1.5 mm, and indicate a high level of consistency between the CFD model and the experimental results. The research result is a numerical model which enables the representation of flow characteristics in hydraulic valves and thus allows a fast CFD analysis at a certain accuracy level. It also allows the significance of the set numerical parameters, including the mesh parameters and the turbulence model, to be estimated from the perspective of its impact on the calculation accuracy of pressure drops on the valve. The numerical model is a basis for designing further prototypes of modern “green” plastic hydraulic elements to be used in zero-emission drive systems.