Delay by Spin-Up of Captive Vortex

Abstract

Recent application of fluidics show increasing importance with respect to signals encoded in flow pulses, in oscillators as well as in closely related devices for correcting the distorted pulse shapes. The parameters of the pulses are adjusted using the output of the fluidic circuits generating the time delays. Currently they are mostly based on the speed of the flow propagation channels. This paper focuses on a much less known delay principle, based on the dynamics of spin-up of a vortex rotating inside a closed cavity and shows some simple fluidic circuits using this principle. Apart from an experimentally investigated model, the manuscript also contains a simple theory for the captive vortex dynamics.