Dynamic modeling and simulation of a relief valve

A nonlinear dynamic model of a relief valve is for mulated in state-space form from fundamental princi ples of rigid-body motion and fluid dynamics. Model parameters are calculated from steady-state character istics and the physical dimensions of the valve. The transient response of the nonlinear model (as well as system eigenvalues and the frequency response of a linearized model) is obtained by digital simulation. Results indicate that the opening time of the valve is linearly related to the dimensionless parameter given by the ratio of orifice length to its radius. The analysis provides design information and perform ance evaluation for fluid systems incorporating relief valves. It is particularly suitable for relief valves for liquids and it can be adapted for other applications.