Study of droplets distribution on canopy of ringsail parachute in light rain

Abstract

As a basal part of the entire study of reliability performance of ringsail parachute and re-entry capsule descending in rain environment, droplets distribution characteristics on canopy surface are investigated firstly via two-phase flow approach in the paper. The model of ringsail parachute and capsule is built on the basis of the sizes of Chinese Shenzhou series spacecraft components. The simulation of droplet trajectories is implemented numerically using the Discrete Phase Model. The numerical simulations considering various rainfall rates and velocities of a ringsail parachute and capsule descending in light rain conditions are conducted. The results show that for one specific rainfall rate, there is a homologous critical value of descending speed of parachute and capsule, which is the dividing line between raindrops being trapped and not being trapped by the canopy; if the descending velocity is less than the critical value, no raindrops will be captured; in raindrops-trapped cases the raindrops are distributed on the bottom skirt zones of the canopy surface and not evenly distributed. The work in the paper will be helpful and significant for the further study of the effects of rain environment on the spacecraft recovery.