Synthetic (zero net mass flux) jets are an active flow control technique to manipulate the flow field in wall-bounded and free-shear flows. The fluid necessary to actuate on the boundary layer is intermittently injected through an orifice and is driven by the motion of a diaphragm located on a sealed cavity below the surface
Lehmkuhl, O.; Rodriguez, I.; Borrell, R. Effect of the actuation on the boundary layer of an airfoil at moderate reynolds number. A: ERCOFTAC Workshop on Direct and Large-Eddy Simulation. "Direct and Large Eddy Simulation XII. DLES 2019. ERCOFTAC Series, vol 27". Berlín: Springer, 2020, p. 313-319. ISBN 978-3-030-42822-8.