Author(s)

J. Kord´ık & Z. Tr´avn´ıˇcek

Abstract

The paper deals with a new design of the hybrid synthetic jet actuator (HSJ), which is based on a novel fluidic diode. The fluidic diodewas tested by a static experiment and its diodicity was evaluated. The same experiment was performed for a second fluidic diode whose planar geometry was taken from the literature and the resultant diodicities were compared. Higher diodicities were achieved with the new design of the diode. The velocity resonance curves were measured at the nozzle output for two variants of the HSJ with a short or with a long nozzle. After that the volumetric efficiencies of the HSJ were evaluated as functions of the frequency. The highest efficiency (over 80%) was achieved at the second resonant frequency of the actuator with the long nozzle. Keywords: synthetic jet, hybrid synthetic jet, rectification effect. 1 Introduction Hybrid synthetic jets, which were first introduced in [1–4], combine the usual synthetic jet and valveless pump principles. The valveless pump [5–10] is a pumping device consisting of a chamber equipped with a moving piston or diaphragm, the chamber is connected to a fluidic diode and a nozzle. The orientation of the fluidic diode is adjusted so that its forward direction is oriented toward the inside of the chamber. Once the diaphragm oscillates, a nonzero net mass flow is created in the nozzle (rectification effect). Unlike the valveless pump, the nozzle of the hybrid synthetic jet actuator (HSJA) issues into ambience where the hybrid synthetic jet (HSJ) is formed. The experimental investigation offers many unexplored possibilities, as hybrid synthetic jets represent a new research topic, with only a few papers dedicated

Keywords

synthetic jet, hybrid synthetic jet, rectification effect.