This study explores rheological properties related to propellant slurries from the standpoint of experiments and simulations.

The casting−curing process is a common technology for manufacturing the Nitrate Ester Plasticized Polyether (NEPE) propellants. The curing process involves a coupled thermal-chemical reaction of the adhesive systems of propellant, which influences the curing stage. Using GID 16 software, a propellant grain curing simulation model was conducted. This study employs a model-fitting method based on non-isothermal DSC experiments to analyze the curing reaction kinetics of propellants. Two methods, Kissinger and Ozawa, were used to determine the activation energy of the curing reaction. The reaction activation energy obtained by the Ozawa method was chosen as the simulation parameter Ea = 59.378 based on the fitting coefficients. The simulation comprehensively onsidered flow, temperature, and curing reaction parameters, achieving multi-field coupling of thermal and curing degree fields during the curing process. The macroscopic temperature variations of the pillars were monitored using thermocouples. The experimental results show that the final curing temperature is stable at about 48.2 °C. At about 21,000 s, the overall temperature of the grain converges. The experimental results were compared with the simulation results, revealing minor discrepancies. Experimental and simulation methods were used to verify the changing law of the temperature field inside the propellant grain. Furthermore, these results have significance for improving the casting−curing industrial process of the composite solid propellant.

N-butylnitroxyethylnitramine (BuNENA) is a high-energy plasticizer with high plasticizing ability, low sensitivity, and high energy. It has broad application prospects in HTPE propellants. Nevertheless, as an energetic plasticizer, it requires treatment to reduce its sensitivity. To this end, the passivation process for BuNENA was simulated using a mixing model analogous to nucleate boiling. This method involves tracking the formation and movement of bubbles using a Lagrange frame, and the bubbles themselves are modeled as rigid spheres subject to buoyancy and viscous forces. A variational multiscale (VMS)-based Euler framework was employed to simulate the fluid surrounding the bubble. The movement process of the bubbles was analyzed, and it was found that the amount of bubbles and the movement speed were higher at high temperatures and in a high vacuum, and the passivation effect on BuNENA was better. At a pressure of 40 mbar and a temperature of 50 °C, BuNENA demonstrated an 89% water removal rate. A comparison of the experimental results with the simulation results revealed slight discrepancies between them. A meticulous analysis of the passivation process for BuNENA is rendered possible by integrating experimental and simulation methodologies, a feat that has immense implications for the realm of composite solid propellant passivation.

The objective of this study was to investigate the distribution of pyrolysis products and the chemical reaction kinetics of a novel composite, GO@CL-20. The GO@CL-20 composite powder was synthesized using a solvent–non-solvent method. The thermal decomposition process of GO@CL-20 was analyzed through thermogravimetric differential scanning calorimetry (TG-DSC). The results indicate that the incorporation of graphene oxide (GO) reduces the activation energy of the sample, thereby catalyzing the thermal decomposition process of the complex. Subsequently, single pulse shock tube experiments were conducted to assess ignition delay time distribution, from which corresponding data on pyrolysis product distribution for GO@CL-20 were obtained. The findings regarding ignition delay times demonstrate that adding GO decreases the energy within the complex system and mitigates its reactivity, consequently prolonging ignition delay times. An important carbon and nitrogen molecule, C₂N₂, was identified in the pyrolysis product distribution; notably, its yield increased progressively with higher concentrations of GO. Finally, mass transfer characteristics and sensitivity analyses for GO@CL-20 samples were performed using CHEMKIN software to preliminarily determine pyrolysis reaction pathways. The results reveal that incorporating GO can significantly alter the thermal decomposition behavior of the entire system; moreover, C₂N₂ exhibits a high cleavage rate along this reaction pathway—findings that align well with experimental observations. This study aims to enhance understanding of CL-20 and GO reaction kinetics—materials with extensive applications in military operations as well as aviation and aerospace—and provides valuable insights for propellant development.