关键词: 立式捏合机, 含能材料, 捏合过程, Fluent, Transition-SST模型, 捏合力矩

Abstract: To investigate the mechanism of action of key parameters such as spindle speed, blade speed, and slurry viscosity in a dual-blade vertical kneader on the kneading process of PBX explosive slurry, and to analyze the influence laws of each parameter on slurry temperature, flow rate, and maximum spindle torque, a numerical simulation was conducted on the mixing and stirring process of slurry in the dual-blade vertical kneader based on the Transition-SST model and the established non-Newtonian fluid rheological model of the slurry. Through structural definition, mesh division verification, and dynamic parameter setting in Fluent, combined with the setting of boundary conditions according to experimental working conditions, and the calibration of simulation parameters based on the experimental data of spindle output torque, the construction of the numerical simulation model was completed. Verification shows that the calculation error of the kneading torque is only 5.2 %, indicating that this numerical simulation method has high reliability. With the help of the constructed numerical simulation method, the influence laws of different parameters (spindle speed, hollow blade speed, solid blade speed, and material viscosity) on the maximum slurry temperature, minimum flow rate, and maximum spindle torque during the mixing process were studied. The simulation results show that within the given parameter range, the spindle speed and solid blade speed have no effect on the maximum temperature of the kneaded slurry, and the contribution degrees of the hollow blade speed and slurry viscosity to the maximum slurry temperature are 55.5 % and 44.5 % respectively. Moreover, the hollow blade speed, solid blade speed, and material viscosity have no effect on the minimum flow rate of the kneaded slurry, while the revolution speed is the only significant factor affecting the minimum flow rate of the slurry in the kneader. Furthermore, the hollow blade speed and solid blade speed have no effect on the maximum output torque of the spindle, and the contribution degrees of the slurry viscosity and spindle speed to the maximum output torque of the spindle are 62 % and 38 % respectively. The obtained results can provide an important theoretical basis for the dynamic change process of material characteristic parameters during the kneading process of energetic materials, as well as the optimization and precise control of the kneading process.

Key words: vertical kneader, energetic materials, kneading process, Fluent, Transition-SST model, kneading torque