Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : November 11, 2020 - November 13, 2020
A synthetic jet has a zero-net mass flow rate at the nozzle outlet but generates a net mass flow rate downstream. Considering the momentum conservation, we supposed that the synthetic jet produces the time-averaged thrust. Furthermore, the thrust induced by the synthetic jet would be unsteady. In order to use the synthetic jet as a thrust control, we experimentally and numerically investigated the unsteady thrust characteristics for the synthetic jet. For a pulsating flow generator, a reciprocating piston operated by a motor with an inverter was used. A torque induced by the synthetic jet was measured by a torque sensor and the thrust was evaluated by the torque based on the moment equilibrium. The unsteady flow around the chamber was calculated by using commercial numerical code and the unsteady thrust was evaluated by integrating the jet direction force acting on the chamber surface. The unsteady thrusts induced by the synthetic jet were confirmed in the experiment and the CFD. In the CFD, the two peaks and the one peak were observed during the blow and suction conditions, respectively. On the other hand, in the experiment, we could not observe two peaks during the blow condition. The discrepancy may be caused by fluid resistance due to the vibration of the thruster.
