Energetic efficiencies of synthetic jet actuators: Commentary on the article by Gil and Strzelczyk

Abstract

Recently, Gil and Strzelczyk (Exp. Thermal Fluid Sci. 76, 2016, 163–174) presented an experimental study focusing on a synthetic jet actuator. Their paper considered, among other points, an evaluation of the energetic efficiency, which was defined in an alternative manner. This commentary demonstrates that the alternative definition can cause a considerable over-prediction of the energetic efficiency in comparison with a previously published method. More specifically, an over-prediction by 60–67% was evaluated for the examples considered.