粒径与形状对逆向位移活塞式供粉性能的影响OA

The powder fuel feeding system directly affects the operating stability,safety and thrust performance of the powder-fueled ramjets.Therefore,a reverse-displacement pneumatic piston powder feeding device was proposed.The effects of aluminum powder particle size and morphology on the steady-state feeding process were analyzed via a coupled Fluent-EDEM simulation.The results show that a stable packed layer is formed at the bottom of the powder hopper during feeding,with a conical particle pile accumulating beneath the feeding pipe.The airflow drives the aluminum powder to converge toward the center for continuous conveying,forming a dynamically stable powder particle distribution.Decreasing particle size markedly improves feeding efficiency.When the particle size is reduced from 150 μm to 50 μm,the efficiency rises by around 47.8%.Aluminum powders with aspect ratios ranging from 1∶1.5 to 1∶2.5 promote the rapid formation of a stable flow regime.However,the steady-state mass flow rate is decreased by about 15%when the aspect ratio reaches 1∶2.5.In summary,it is recommended that aluminum powder with a particle size of 50 μm to150 μm and an aspect ratio less than 1∶2 should be used in this feeding device.