Design And Research On The Piezoelectric-Piston Synthetic Jets Actuator

Synthetic jet technology as a new flow field of active control technology has an attractiveapplication prospects in the field of aerospace. It has Caused widespread concern in the research field.It is caused by various methods drive cavity volume cyclical changes. While, periodic fluid jet isformed at the exit external. Piezoelectric synthetic jet actuator drive piezoelectric patches attached tothe diaphragm on the incentives to produce such cyclical. This actuator has the advantages of simplestructure, small volume, the driving electrical signals easily obtained. Thus, it becomes the keyresearch direction of synthetic jet technology.This paper starts From internal and external flow field characteristics of piezoelectric synthetic jetactuator and its principle of how it works. It draws that improving the change in volume of the cavityduring one circle should be used as the main method to improve the performance of the actuator. Toachieve this purpose, the new design of the actuator: a piezoelectric-piston synthetic jet actuator waspresented. The computer modeling and simulation and hot wire anemometer detective were applied tothis new type of actuator. The results were discussed. And a electric-acoustic analogy theory analysismethod for solving the problems of the existing simulation were presented. It can simplify theanalysis of the principle of piezoelectric synthetic jet. It could be obtained that the amplitude of thevibration of the membrane has an important influence on the performance of the drive. In order tomake more effectively analysis on the signal obtained by the test, a new signal processing method ispresented. In this paper, the research content following:First, according to the working principle of the piezoelectric synthetic jet actuator, a new actuatorstructure was presented: Piezoelectric–Piston synthetic jet actuator as well as a simplified flatPiezoelectric-Piston synthetic jet actuator. The reasons for the enhancement of the drive performancerelative to general actuator were discussed. Several different numerical models were applied to theflow field numerical analysis caused by the new structure actuator. It was included that RSM modelfor the numerical simulation of the flow field caused by actuator has the best result. Based on RSMmodel, the influence of various parameters on the structure of the actuator was studied. Thus, thefactors that affect the driving effect of the new actuator were obtained. In accordance with the designideas of the new actuator, a lot of specimens with different size were manufactured. Detailed recordsby hotwire anemometer were obtained from the outflows fields of the actuators. It’s improved that thenew actuator is indeed beneficial to enhance the strength of the synthetic jet and also the impact ofvarious parameter on the structure of the actuator. After comparing the results of the numerical simulation and experimental validation, the electric-acoustic analogy theory was presented for thestudy of the structure of the actuator. Finally, the Hilbert-Huang transform processing was applied tothe velocity signal of the flow recorded by the hotwire anemometer. It shows that Hilbert-Huangtransform can be effectively applied to the analysis and processing of the new actuator.This thesis is funded by the National Natural Science Foundation of China (itemnumber:90405008).