Study Of The Extrusion Simulation Of Propellant

Extrusion process has been widely used for propellant production. Flow process and the quality of propellant are effected by process parameters. POLYFLOW, one of CFD softwares with important application value, was applied in simulating the extrusion process of propellant and discussing the influence of process conditions, instead of ineffective traditional experimental method.In this paper, Rosand RH2000 capillary rheometer was used for rheological test, and the results were good fitted with Bird-Carreau constitutive model. Moreover, the experiment discussed the relationship between the rheological properties of propellant material with processing temperature or solvent ratio influence.Runner models of signal-hole die, medicine cylinder with three single-hole die,7-hole die and lace 37-hole die were made by Solidworks, whereas POLYFLOW was applied in simulating the extrusion process of propellant.In this article, how the solvent ratio, processing temperature, inflow volume rate as well as slip condition influence the extrusion process of single-hole propellant and 7-hole propellant were investigated. Meanwhile, the extrusion process of three single-hole propellant and lace 37-hole propellant were preliminary investigated. Results indicate that, the increase of solvent ratio or extrusion temperature would decrease the viscosity of propellant material and improve the flow performance, therefore, molding pressure would reduce and the velocity would be uniform. High pressure drop and non-uniform velocity would appear owing to high rate of volume flow. However, improving the smoothness of wall was good for lowering pressure and making the velocity distribution more uniformity. According to the research, the compression pressure needed for the shaping of three single-hole propellant is higher than that of one single-hole propellant, meanwhile, its velocity uniformity is lower. It’s hard to control the quality of lace 37-hole propellant for its bad velocity uniformity because of complicated shape in die lip. The quality of single-hole propellant and lace 37-hole propellant can be improved through increasing solvent ratio appropriately and rising the processing temperature as well as enhancing the smooth degree of die profile.