The Biased Laminar By-Pass Fluidic Flowmeter

Abstract

This paper demonstrates that the range of a fluidic flow meter can be significantly extended by connecting it in parallel with a fixed laminar by-pass resistance. Analysis shows how for any particular specification, there is an optimum combination of meter and by-pass which maximizes the flow range. Validation tests were done in air, using a fluidic target meter integrated into a housing with a laminar by-pass of parallel rectangular cross section passages formed between flat plates. Results obtained showed excellent agreement with analytical predictions, almost doubling the operating range for the typical specification chosen, a major advance in the context of the previous research aimed at extending meter range. In principle the concept should be applicable to any flowmeter having a suitable Eulerian pressure-flow characteristic.