The Development of a High Pressure Pulsating Flow Hydraulic Servomechanism
Beswick, Ian Montague
Pulsating flow 9p.f.) hydraulic control systems offer a number of unique advantages over conventional direct or continuous flow (c.f.) systems. These advantages make pulsating flow control particularly useful and desirable in certain specific applications. these applications are related mainly to the fields of high speed aeronautics and control at high power levels within radioactively contaminated environments. For example, p.f. hydraulics permits the simultaneous use of two or three different hydraulic fluids within the same system. This arrangement is designed to confine the effects of nuclear irradiation or adverse temperature conditions to the appropriate sections of the hydraulic control system. This report, then describes the development and subsequent experimental analysis of a p.f. hydraulic servomechanism. This servomechanism was designed to operate at pressures up to 3000 psi and control an inertial load of 96 pounds by means of a conventional linear actuator, an electrohydraulic servovalve, and the usual additional closed loop control apparatus. The aim of the project was essentially to derive fundamental information concerning the characteristics of this type of control, thus providing a sound basis for the future development of this work. The initial aim has been achieved here and the results obtained indicate that high pressure p.f. hydraulic servos are feasible devices, and that in certain applications they do in fact offer unique advantages over the more conventional type of direct flow systems. It is anticipated that the development of the laboratory prototype servo will be continued, and that in the future, investigations will be performed on both an experimental and a theoretical basis.