The flow field of the piston-type synthetic jet actuator (SJA) under high ambient temperature was investigated numerically and experimentally. The effects of the actuation frequency and orifice diameter on conventional SJA and novel SJA were analyzed. The results indicated that the auxiliary air inlet can significantly increase the SJA performance under high ambient temperature. Compared with the conventional SJA

the novel SJA can increase the inlet mass flow rate

peak cylinder pressure ratio and peak jet momentum

despite of a little decrease of the peak jet velocity. The peak efficiency of the auxiliary air inlet lied in high actuation frequencies or small orifice diameter. Compared with the conventional SJA

the inlet mass flow rate

peak cylinder pressure ratio and peak jet momentum of novel SJA increased up to 23073%

10397%

and 10737%

respectively

of conventional SJA at actuation frequency of 250 Hz

orifice diameter of 2 mm.