A confined jet sometimes causes a self-exited oscillation due to the existence of a downstream target. In this work, the authors study this phenomenon. More specifically, the authors deal with a simple fluidic oscillator; namely, a two-dimensional confined jet into an abruptly-expanding channel with a downstream target of a square cylinder. The authors conduct the velocity measurements by an UVP (ultrasonic velocity profiler). Besides, the flow patterns in the fluidic oscillator are observed by a PIV (particle image velocimetry). As a result, the authors reveal the geometrical effects upon the range of stable jet's oscillation, such as the aspect-ratio effect, the channel-breadth effect, the cylinder-size effect and the cylinder-distance effect, together with the Re effect.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.