Novel Piston-Type Synthetic Jet Actuator with Auxiliary Air Inlet

A novel piston-type synthetic jet actuator (SJA) is developed which has an auxiliary air inlet close to bottom dead center (BDC) to alleviate the difficulty during suction duration. The flow characteristics of the novel SJA are studied numerically and experimentally. The effects of the orifice diameter, actuation frequency, and height of the auxiliary air inlet on the actuator performance are also analyzed. The results indicate that the auxiliary air inlet significantly improves the performance of the SJA, especially for small orifices and high actuation frequencies. Compared with the conventional piston-type SJA, the mass flow of the novel SJA is increased significantly, which is the major reason for the increase in cylinder pressure, maximum jet momentum, duty cycle, and efficiency of the actuator.