Abstract:  A numerical model is established using the AMESim software for the operation performance of a nitrogen micro-propulsion system driven by a piezoelectric valve with a nitrogen storage pressure of 1.5×10 7 Pa and a thrust range of mN level. The transient pressure and mass flow of the nitrogen tanks and the pressure reducing valve during nitrogen filling are calculated and analyzed. The transient characteristics of the piezoelectric proportional valve integrated with a nozzle under the starting conditions are also studied. Consequently, the effects of the driving voltage on the displacement of the valve core, the transient thrust of the nozzle, and the response time of the valve core and thrust force are investigated. The results show that the response time and stable displacement of the valve core of the piezoelectric proportional valve are 0.64 ms 〖JP2〗and 3.67 μm respectively as the driving voltage is set to 80 V. The nozzle thrust reaches a stable value (0.588 mN)〖JP〗 at 8 ms after startup. The piezoelectric proportional valve is of a quick response in the movement of the valve core, and there is a good linear relationship between the drive voltages and thrust forces under the starting conditions. This indicates that the thrust linear control at the level of mN can be achieved by changing the driving voltage.

Key words:  Drag-free satellites, Nitrogen gas micro-propulsion systems, AMESim simulation, Operation characteristics