Computer-Aided Design Procedure for Laminar Fluidic Systems

Abstract

This paper presents a computer aided procedure for the design of laminar proportional fluid amplifiers and gain blocks. The procedure is based upon a fundamental analysis of the flow regimes in an amplifier. With the aid of a computer, amplifier static and dynamic characteristics, required in control system design, may be determined as a function of geometry and fluid properties. The procedure is illustrated and evaluated by comparison of predicted design and experimentally measured performance. The procedure has been applied to individual elements designed by three different organizations, multistage gain blocks, and laminar jet rate sensor preamplifiers. The results of the procedure are shown to be quite accurate over a wide range of amplifier geometries (eleven different amplifiers with aspect ratio from 0.25 to 3 – a range of 12 to 1 – and nozzle sizes from 0.5 to 10 mm) and operating fluids (both air and oil). Experimental measurements were within 10 percent of the design predictions for amplifier gains, operating resistances, and bandwidth for all examples investigated.