Effects of Piezoelectric Material Properties of the Proportional Valve on the Dynamic Performance of a Nitrogen Gas Micro-Propulsion System

Owing to low dry mass, high precision thrust control, simple structure and no pollutions, the nitrogen gas micro-propulsion systems can meet the demands of drag-free satellites where the payload follows a geodesic path through space only perturbed by gravity and not by non-gravitational forces. In this study, the nitrogen gas micro-propulsion system was modeled using AMESim software. Present onedimensional system model consisted of two nitrogen tanks, a latching valve, a pressure reducing valve and a piezoelectric proportional valve which driven by piezoelectric patches and integrated with a thruster. The nitrogen gaseous pressure in the tank and the buffer cavity of the proportional valve were set to 150 bar and approx. 2. 0 bar, respectively. The electromechanical coupling coefficient, elastic constants and relative permittivity of the piezoelectric patches were varied from 0. 518 to 0. 962, 1. 536e-l1 to 2. 834e – 11 and 3500 to 7500, respectively. The modelling results revealed that compared to elastic constants and relative permittivity, the electromechanical coupling coefficient had a most influence on the opening of valve and thrust force.