离子-液滴混合模式下离子液体推力器性能调控研究

Performance Control of Ion-Droplet Mixed Mode of Ionic Liquid Thrusters

离子液体推力器在不同工作条件下会发射液滴或离子,当发射粒子包含液滴和离子时,推力器处于离子-液滴混合模式。本文对离子-液滴混合模式下离子液体推力器的性能调控展开研究,对离子液体推力器样机进行实验,为避免电化学反应导致实验无法进行,采用负直流电源供电,收集发射电流并拍摄液面变化图像,结合理论计算判断实验中推力器处于离子-液滴混合模式。通过计算得到不同供给电压下离子和液滴对应的发射电流和流量,结果表明离子电流占比最高约为98.99%。进一步计算发现,推力和比冲随电压的增大而增大,效率随电压的增大呈现先减小后增大的趋势。此外,计算发现荷质比的减小会导致推力、比冲和效率的增大。在供给流量为2.8n L/s,电压为-3100~-3800V的实验条件下,离子液体推力器样机推力约为6.66~12.54μN,比冲约为187.48~353.07s,效率的约为6.02%~6.87%。

Ionic liquid thrusters emit droplets or ions under different modes.When the emitted particles contain droplets and ions,the thruster is working in ion-droplet mixed mode.In this paper,the performance con⁃trol of ion-droplet mixed mode was studied.The experiment of the ionic liquid thrusters was performed,the emis⁃sion current was collected and the image of the liquid surface was taken.In order to avoid the interruption of the experiment due to electrochemical reaction,a negative DC power supply was used.Combined with theoretical cal⁃culation,the thruster was estimated to be working in the ion-droplet mixed mode in the experiment.The emission current and flow rate of ion and droplet under different supply voltage are calculated.The results show that the highest ion current proportion in the experiment is about 98.99%.Further calculation shows that thrust and specific impulse increase with the increase of voltage,and efficiency decreases first and then increases with the in⁃crease of voltage.In addition,by calculation,it is found that the reduction of specific charge generates the de⁃crease of thrust,specific impulse and efficiency.With the volume flow rate of 2.8nL/s and the voltage range of-3100~-3800V,the thrust range of the thruster is 6.66~12.54μN,and the specific impulse range is 187.48~353.07s,and the efficiency range is about 6.02%~6.87%.