PROPOSAL OF INNOVATIVE FLUID DYNAMIC NONLINEAR SERVOVALVE SYNTHETHIC MODELS

The design of modern flight control systems involves the need of highly detailed models in order to analyse the specific components or subsystems; on the contrary more simple and synthetic models, nevertheless having an acceptable level of accuracy, are requested for the simulation of the dynamic behaviour of entire systems. Aims of the work is the development of some innovative synthetic fluid-dynamic servovalve models, characterized by a semi-empirical formulation, having the ability to take into account the effects of a variable supply pressure and of a leakage acting among the control ports connecting the valve to the motor element; to the purpose, five different models have been proposed and their behaviour has been compared to an highly detailed model one. The merits or demerits of the proposed models, related to their ability to properly describe the fluid-dynamic behaviour of the valve, are represented by the diagrams reporting their “characteristics” and by the simulations of a typical servomechanism obtained by their use.