Nonlinear Dynamics Of An Electrohydraulic Flapper Nozzle Valve

A nonlinear model of an electrohydraulic flapper-nozzle valve is developed, using an energy-based approach. Nonlinearities are found in the resistances, compliances, and the inertances; the latter produce state-dependent coupling terms. The model is applied to a valve designed for pulse-width modulation (PWM). Most model parameters are derived from a priori design parameters, but some were found from a series of experiments which also served to confirm the model. The valve and its model responded satisfactorily to PWM signals up to 500 Hz.