Powder feeding enhancement of powder propellant supply system by using gas-permeable piston

Stable and efficient powder propellant feeding is the key to the excellent performance of powder engines, but the previous structures of supply systems pose a challenge to it. Therefore, structural optimization has been made for the powder propellant supply system to promote feeding. Specifically, the traditional sealed piston is optimized as the gas-permeable piston that has an annular gap between the piston edge and the silo wall to allow the driving gas to permeate into the powder column, producing the gas pressure gradient to increase powder axial pressure and leading to the cancellation of fluidization gas line at the front of the silo to reduce gas turbulence and powder fluctuations. There is a discovery that the powder achieves mass flow under only airflow and discharged powder amount can be maximized as much as possible by combining with gas-permeable piston, which also supports the feasibility of the optimized system and realizes a more stable and higher flux flow. In addition, the gas-permeable piston with a gear-shaped end face has the best overall performance. Through this work, we wish that our research can provide valuable guidance for the design of powder propellant supply systems to meet the requirements of spacecraft power systems.