Design optimization of a special relief valve with response surface methodology

This paper describes the utilize of a numerical procedure for the analysis and the optimization of an hydraulic component, namely a particular direct acting relief and anti-cavitation cartridge valve. The element taken as reference is usually connected to a hydraulic line with the aim of keeping the circuit pressure between two different set values; moreover it can work as anti-shock valve, avoiding pressure peaks. The developed procedure is based on Response Surface Methodology techniques, adopting the path search method known as Steepest Descent. For this purpose, the valve behaviour is analytically described by means of a properly defined objective function. The procedure approximates this objective function with a simple model whose coefficients are evaluated using the predictions performed by a AMESim® model of the valve, developed in C++ language by the authors. The sets of simulations for the fitting model are planned according to Design Of Experiments techniques. The entire optimization algorithm has been developed with MATLAB® scripts, which are able to plan the simulation with the AMESim® model of the valve, automatically execute the simulations, post process the results and finally establish the optimal configuration of the component taken as reference. The considered starting point for the optimization process is given by a stock configurations of the valve, considered also for the experimental validation of the AMESIM® model in previous works. Three different optimal configurations of the valve, for different values of the preset pressure, have been proposed, and prototypes of the new designs have been realized. Experimental investigations point out the improved performance of the proposed designs, highlighting the potentials of the developed optimization methodology.