Numerical Simulation And Mixing Uniformity Analysis Of Aluminized Explosives Simulants Mixed In A Twin Screw Extruder

The study of metallized explosives is an important branch of military mixed explosives development, aluminized explosives becomes the hot research area of high explosives. The mixing uniformity of aluminum powder in the explosive basis material has great influnce on explosion power of matallized explosives. Compared with tranditional mixing equipments, TSE-extrusion technology of energy materials has great adventage of continous, high efficiency and green flexibility. Explosives simulants with 20%content of aluminum powder is the study object of this article, of which flow law effected by technological parameter of twin screw was studied, and the analysis result can be theoretical reference of the evaluation of mixing capacity and safety performance of twin screw-extrusion of aluminized explosives.According to the rheological parameter of aluminized explosive simulants, This article simulate the mixing flow of 5 configuration, pressure difference and screw speed, depending on simple variable method. Shear rate distribution, weighed average shear stress, mixing index, pressure distribution, back flow coefficient, resident tme distribution, vicous heat and temperature were researched, to analyze the mixing capacity and safety performance effected by screw speed, pressure difference and screw configuration. In addition, quantitative evaluation method of superfine powders mixing uniformity was proposed, which is based on Shannon entropy and agglomerate coefficient. With this method, simulation results were verified by experiments.Simulation analysis results show higher screw speed improve the mixing capacity of screw, but the safety performance become lower.; higher pressure difference also improve admixtrue, safety level keeps steady; screw elements with larger head, reverse screw elements and reverse kneading disks, have better performance on dipersive mixing. Compared with other 4 screw configutation,The one with reverse screw elements and kneading disks has better performance on mixing and safety.Experiment results show that the numerical simulation have great accuracy on mixing performance. Mixing voefficient method is applicable on evaluation of ultrafine aluminum powder in the explosive simulants, and can be a new method for mixing evaluation of ultrafine content of composites.