Design and characteristic analysis of a piezoelectric micro-jet generator

Considering the lubrication failure of spacecraft, an original piezoelectric micro-jet device which takes the control moment gyro (CMG) as specific application object is proposed. The working principle of the micro-jet device was analyzed. The structure designs were illustrated detailedly. In order to choose a suitable working mode, modal analysis under the action of fluid-structure interaction was conducted, it showed that the first mode of piezoelectric vibrator is more desirable compared to other modes. Also the dynamics analysis of the piezoelectric vibrator was studied, the results revealed that the effect of the fluid should not be neglected when researching the characteristics (resonance frequency, vibration amplitude, etc.) of the micro-jet device; as the increase of the thickness of the piezoelectric ceramic piece or the metal diaphragm, the resonance frequency of piezoelectric vibrator increased, but the maximum vibration amplitude of piezoelectric vibrator decreased; as the increase of the liquid density, both the resonance frequency and the maximum vibration amplitude decreased obviously; as the increase of the liquid depth when the liquid viscosity is low or can be ignored, either the resonance frequency or the maximum vibration amplitude did not have much change.