Abstract
A confined jet sometimes causes self-exited oscillations due to an existence of a downstream obstacle.This phenomenon is useful for fluidic oscillators, heat/material mixers and flowmeters, in order to realise a low-cost high-reliability device without mechanically moving components. In the present study, the authors deal with this phenomenon at low Reynolds numbers (Re=500), experimentally. More specifically, the autors conduct a time series of flow visualisations and PIV(Particle Image Verocimatry) analyses, with the measurement by UVP for accuracy check. As a result, the autors propose a new definition of length scale of vertical structures and propose a formula to predict the oscillation frequency using the length scale.
