Steric Effects on Space Electroosmotic Thrusters in Soft Nanochannels

The influence of steric effects on the performances of space electroosmotic thrusters (EOTs) was numerically delineated in soft nanochannels for which its walls are covered with polyelectrolyte materials. The size effect of the ionic species, namely the steric effect, is neglected in many previous research studies, but it has vital influences on electrostatic potential and electroosmotic velocity, which is further introduced into the present study in order to understand and improve the exploration of nano electroosmotic thrusters with soft channels. The thruster's thrust, specific impulse, total input power, thruster efficiency and thrust-to-power ratio are computed based on finite difference methods. It is found that the thruster's thrust and specific impulse increase with the steric parameter while the efficiency and thrust-to-power ratio possess opposite trends due to the enhancement of Joule heating dissipation. For real situations with the consideration of ion size, although the thruster's thrust could be promoted, the efficiency is only 30-70%, and the peak values of thrust-to-power ratio fade away.

Automated summary

The influence of steric effects on the performances of space electroosmotic thrusters (EOTs) was numerically analyzed in soft nanochannels covered with polyelectrolyte materials. The size effect of ionic species, known as steric effect, has significant impacts on electrostatic potential and electroosmotic velocity, affecting the thruster's thrust, specific impulse, total input power, efficiency, and thrust-to-power ratio. Although the thruster's thrust may increase with the steric parameter, the efficiency is only 30-70% in real situations taking ion size into consideration, with the peak values of thrust-to-power ratio diminishing.