Discharge characteristics of non-gravity-driven powder in horizontal silos

Abstract

Powder flow inside horizontal silos is essential to ensure the efficient operation of the spacecraft using powder engines under horizontal flight positions. In the present work, the discharge characteristics of non-gravity-driven powder in the horizontal silo were investigated experimentally, with an emphasis on the half cone angle, aeration position, and additional pressure. The experimental results show that the mass flow rate first increases with decreasing half cone angle and then approaches saturation. Aerating at the cylinder was proved to be able to significantly increase the mass flow rate compared with the previous aeration at the cone. Increasing the additional pressure can effectively improve the mass flow rate, but there is a limit value called pressure surcharge limit to maximize the discharge rate. And aerating at the cylinder can further increase the pressure surcharge limit as well as the maximum mass flow rate, which is close to the ideal flow rate based on the liquid-like hypothesis. Finally, an index η is proposed to evaluate the overall flow-promoting effect to determine the optimal aeration position.