Scientific Bulletin of the Politehnica University of Timisoara Transactions on Mechanics Special issue Workshop on Vortex Dominated Flows – Achievements and Open Problems Timisoara, Romania, June 10 - 11, 2005 APPLICATION BASED EXPERIMENTAL RESEARCH REGARDING AUTOMATION FLUIDIC DEVICES Liviu VAIDA. Prof.* Department of Thermal Machines and Equipments Technical University of Cluj-Napoca Dan OPRUTA. Prof. Department of Thermal Machines and Equipments Technical University of Cluj-Napoca Lucian NASCUTIU. Assist. Department of Thermal Machines and Equipments Technical University of Cluj-Napoca Corina GIURGEA. Senior Lecturer Department of Thermal Machines and Equipments Technical University of Cluj-Napoca Calin VAIDA. PhD. Student. Technical University of Cluj-Napoca *Corresponding author:103 Muncii Bv, 400641, Cluj-Napoca, Romania Tel.: (+40) 264 401604, Fax: (+40) 264 415490, Email: dan@ddd.ro ABSTRACT The paper presents a synthesis over the interest and results obtained by the research group of hydraulics regarding the fluidic devices and the state of research regarding the vortex ones. There have been created the premises for the beginning of s series of experimental research in correspondence with the technical capabilities presently existent within the laboratory. KEYWORDS Fluid amplifier, vortex devices, jet flow. 1. INTRODUCTION After a period of explosive development in the 60s and 70s, followed by a period of neglectness, nowadays the fluidic devices and fluidics in general are again a focus point in the attention of specialists. There are known fluidic devices based on the following principles [2]: • the jet interaction; • the jet interaction with a specific profile, named flap (also known as the Coanda effect); • the transition from a laminar to turbulent flow regime (vortex). Either in case of fluidic devices functioning based on the first two principles enumerated above, or in case of devices functioning in turbulent regime, the output signal will result, from the interaction of two jets, a principal feeding one and a second one, for command having lower pressure. Such a fluidic device has, in general, a feeding component and one or two command plugs, exhausting channels and channels for the output signal (see figure 1). Left side command Right side command Exhaust Exhaust Output Tank Supply Figure 1. The connections of a bistable fluidic device in the hydraulic circuits The interaction of the two jets produces, as output, a flow having a higher pressure than the command pressure, which makes this type of devices to be known as fluidic amplifiers. From the functionality point of view, the fluidic devices can be classified as bistable (see figure 1) or monostable (see figure 2). In this second case, due to the fact that the jet has a preferred flow direction (the left channel) the switching of the feeding flow will be made only on the right branch, for this being necessary a single command.