| Summary: | 碩士 === 國立成功大學 === 航空太空工程學系碩博士班 === 101 === This thesis experimentally studies the application of synthetic jet actuator (SJA) made of piezoelectric (PZ) material in enhancing the aerodynamic performance at low Reynolds numbers. First of all, the fundamental properties of the SJA are investigated by the hot-wire anemometer used to measure the exit velocities of the SJA with different excitation frequency on the PZ material. At the resonance frequency, the exit velocity of the SJA is highest than others. Next, the wind tunnel experiment is conducted to measure the force acting on the wind tunnel model of the NACA 633-018 with the SJA excitation at on and off conditions. To analyze the lift and drag difference with different excitation frequency, 200Hz excitation case is more effective at the low angle of attack and for 300Hz~500Hz excitation case is suitable the high angle of attack.
Finally, for active flow control application of the synthetic jet actuator is realized in the Spoonbill-100 UAV flight test. There are twenty pieces of actuators installed on the left side of the main wing. The flight test results indicate that the excitation frequency at 500Hz is the only effective frequency to enhance the lift. Therefore, the extra lift will generate the roll moment coupled with the yaw moment in real flight test. In comparison with the wind tunnel experiment and flight test, the effective excitation frequencies are very close to the fundamental frequency of the shear layer disturbances of the wing tested.
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