Abstract: Modeling study of droplet’s in colloid thruster is conducted in this paper. Motion of droplets is investigated by using the Lagrange tracking method. Velocity distribution and spatial distribution of droplets are obtained. The effect of ambient pressure on spray angle，axial velocity distribution of droplets and performance of the thruster are analyzed. It is shown that the axial velocity of droplets and performance of the thruster increase and spray angle is less influenced with the decrease of the ambient pressure. While ambient pressure is less than the threshold pressure, the effect of ambient pressure on the spray process, velocity distribution of droplets and performance of the thruster can be ignored.

Key words: spray, motion of droplet, numerical simulation