“田园一号”微推进系统设计与性能测试

针对“田园一号”微纳星编队飞行任务的技术需求，开展了微推进系统的总体设计。常规冷气推进由于其比冲低、贮存压力高、结构复杂，难以满足微纳卫星需求。选择R134a作为推进工质，通过将推进剂液化，减小系统体积。基于3D打印技术，设计贮箱、稳压罐、管路一体的推进系统。采用MEMS加工工艺，设计并研制出电加热喷口，从而提高系统比冲。分析了不同喷口尺寸、供气压力以及温度下所产生的推力和比冲大小，确定出喷口设计。表征测试所研制的电加热喷口，结果表明喷口加工误差控制在2%以内。真空条件下，采用扭摆测量系统测试推力器推进性能，测试结果表明，当稳压罐内气体压力在0.1～0.2 MPa变化时，推力大小为5～10 mN。当喷气温度从25℃升至95℃时，推进系统比冲可提升10%以上。

Design and performance test of TY-1 micro propulsion system

In response to the technical requirements of the "Tianyuan-1（TY-1）" micro/nano satellite formation flight mission，the overall design of the micro propulsion system was carried out.Due to low specific impulse，high storage pressure and complex structure，the conventional cold gas propulsion is difficult to meet the requirements of micro/nano satellites.R134a was chosen as the propellant，and by liquefying the propellant the propulsion system volume can be reduced effectively.Based on the 3D printing technology，the storage tank，plenum chamber，and the pipe can be integratedly designed.To improve the system specific impulse，the heating nozzle was designed and manufactured by using MEMS processing technology.The thrust and specific impulse were analyzed under different nozzle sizes，gas pressure and jet temperature.Based on the analysis result，the nozzle design was confirmed.The heating nozzle characterization test shows that the error of manufacture is controlled under 2%.Under vacuum conditions，the thrust performance was tested by using torsion pendulum measuring system.The results show that this propulsion will produce thrust between 5 and 10mN if the pressure is controlled between 0.1MPa and 0.2MPa.Besides，the specific impulse will increase by 10% if the jet temperature is raised from 25℃ to 95℃.