Experimental investigation of a fluidic actuator generating hybrid-synthetic jets

Hybrid-synthetic jets are similar to the usual zero-time-mean-flow synthetic jets, differing from them by superposition of a steady outflow from the nozzle. This makes the hybrid-synthetic jets suitable for applications like impingement cooling, where the usual synthetic jets fail because of the re-ingestion of the heated fluid. The discussed actuator generating these jets operates without any moving parts. In contrast to the better known rectifier type actuators developed recently e.g. by Trávníček, Fedorchenko, and others, it is based on the idea of a fluidic alternator. Experiments with an alternatior-type actuator model, operating with air, concentrated on the oscillation frequency and its dependence on parameters like feedback loop length. In spite of similarity to the analogous actuator described in Tesař et al. in 2006 the present results are very different.