Design Optimization of Electro-Hydraulic Valve Performance Through Simulation and Experimental Methods.

The main purpose of the semi-active damper (SAD) is for optimizing vehicle control to improve safety, comfort, and dynamics without compromising the ride or handling characteristics. The SAD is equipped with a fast-reacting electro-hydraulic valve to achieve the real time adjustment of damping force. The electro-hydraulic valve discussed in this paper is based on a valve concept called “Pilot Control Valve (PCV)”. One of the methods for desired force characteristics is achieved by tuning the hydraulic area of the PCV. This paper describes a novel development of PCV for practical semi-active suspension system. The geometrical feature of the PCV in the damper (valve face area) is a main contributor to the resistance offered by the damper. The hydraulic force acting on the PCV significantly impacts the overall performance of SAD. To quantify the reaction force of the valve before and after optimization under different valve displacements and hydraulic pressures were simulated using comprehensive three-dimensional (3D) Computational Fluid Dynamics (CFD) methods. For computational model validation purposes, PCV prototypes of the optimized design were procured and tested on a suitable test rig to obtain the hydraulic damping force characteristics at different input current signals. The proposed virtual development method using CFD simulation allows early selection of semi-active valve before physical prototype build. The performance characteristics of a prototype derived from the optimal design of the SAD assembly are presented. The simulation and experimental results show an improvement in the semi-active damping force under certain conditions. This capability is crucial for systems like SAD, where rapid and precise control of oil flow is essential.