The first preferred embodiment of an improved fluid mixing system comprises a synthetic jet actuator aligned perpendicular to a primary fluid flow. When the synthetic jet actuator is driven at a very high frequency, small scale mixing of the primary fluid flow can be effectively controlled. A second preferred embodiment for a mixing system comprises at least one synthetic jet actuator attached to the housing of a primary jet such that the direction of the synthetic jet flow will be parallel to the direction of the primary jet flow. If the two jets are allowed to operate at the same time, the synthetic jet actuator will have the effect of more effectively mixing the primary jet into the ambient fluid. Another embodiment of an improved mixing system comprises a synthetic jet actuator situated in a closed volume. The fluid flow created by the synthetic jet actuator in the closed volume will greatly aid mixing of the fluids in the chamber without injecting any new matter into the chamber.