Optimal design of an electro-hydraulic flow control system using laser velocimeter feedback

An electro-hydraulic flow control system has been designed which utilises feedback from a laser velocimeter. The velocimeter cannot be used to measure flow rate directly. Therefore a relationship has been developed, based upon a digital computer finite difference solution of the Navier Stokes equation for incompressible flow, between volume flow rate and centre-line velocity. A mathematical model, obtained from measured open-loop centre-line data was used as the basis for control system optimisation using an analogue computer, with predicted responses for centre-line velocity being in close agreement with experimental results.