CFD Assisted Steady-State Modelling of Restrictive Counterbalance Valves

The counterbalance valve is an important component in many hydraulic applications and its behaviour hugely impacts system stability and performance. Despite that, CBVs are rarely modelled accurately due to the effort required to obtain basic model parameters and the complexity involved in identifying expressions for flow forces and friction. This paper presents a CFD assisted approach to steady-state modelling of CBVs. It is applied to a 3-port restrictive commercially available counterbalance valve. The model obtained is based on detailed measurements of the valve geometry, a single data set and CFD modelling and includes flow forces and friction. The CFD assisted model is compared to experimental data at three temperatures and two versions of more classical steady-state model based on the orifice equation, uniform pressure distribution and experimental results. The results support the CFD assisted approach as a way to increase modelling accuracy. The load pressure corrected coulomb friction model used manages to capture the changes to hysteresis with temperature but not the changes with pilot pressure.