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A visual experiment platform for high-pressure gas jet impacting the bulk-loaded liquid was designed and built in order to investigate the real law of the interaction between the high-pressure gas jet and the liquid medium during the liquid-balance launch of rocket launcher. The experiments of single-phase gas jet injection and the high-pressure gas jet at different temperatures impacting the bulk-loaded liquid were carried out, and the effects of gas temperature on the characteristics of the gas-liquid flow field have been revealed. The results show that the turbulent mixing between the high-pressure gas jet and the liquid medium leads to the appearance of pressure fluctuations in the gas chamber connected to the nozzle. The higher the gas temperature, the greater the amplitude of the pressure fluctuations. Under the impact of high-pressure gas jet, a gas cavity with an arc-shaped head is formed inside the bulk-loaded liquid. The higher the gas temperature, the faster and more unstable the development of the gas cavity and the flow field. The displacement equation of the gas cavity confirms to the first-order exponential decay function, and the error between the fitting value of the established mathematical model and the measured value is within 2%.

Different charge structures have different interior ballistic performance. Existing research is based on experimental measurements or the lumped parameter method to obtain limited ballistic characteristics, which indirectly impacts the analysis of the parameters’ distribution, requiring a complex modeling solution process. Besides this, the ignition performance of different charge structures needs to be further explored. The disadvantages of previous studies have limited the feasibility of further optimization of the composite charge structure. In this paper, we apply a two-dimensional two-phase flow method based on the Eulerian–Lagrangian model to study the performance of different composite charge structures. First, we establish the mathematical model of different particle types based on interior ballistics, which is directly related to the research foundation of subsequent ballistic performance. Next, we investigate the multi-scale reaction flow of complex charge structures by the two-phase flow method and obtain the distribution of parameters in the chamber. Finally, we conduct a study with different particle charge parameters to explore the sensitivity of ballistic characteristics to structural parameters. The results show that the tubular propellant has good ignition performance in different charge structures, and the ignition consistency can be improved by charging tubular propellant in the center of the chamber. However, more tubular propellants are ineffective at significantly improving ignition performance, and result in a decrease in combustion chamber pressure. These results may be promising for the optimization of various charge structures.

The partially cut Multiaperture stick propellant is a new concept charging structure. In this paper, in order to accurately obtain the change and development process of the two-phase flow field in different stages of the whole interior ballistic process in this propulsion concept system, a coupled calculation model of computational interior ballistic is established, which converts the Euler-Lagrange method to the Euler-Euler method. Firstly, at the initial stage of ignition, the Euler-Lagrange method is used to describe the flow field. During this period, the gas phase is based on Euler coordinates, while the solid phase is based on Lagrangian coordinates. After the projectile starts, the partially cut Multiaperture stick propellant is fractured into granular propellant. The flow field is converted to describe by the Euler-Euler method by using the initial mapping method. Finally, by comparing the calculated results with the experimental results, the maximum pressure error is only 0.54%, which verifies the accuracy and effectiveness of the coupling calculation method. It effectively captures the distribution of the physical parameters in the combustion chamber, providing a new research method for the computational interior ballistic of the propulsion concept. Based on this method, the pressure distribution in the propulsion concept system is obtained, and no obvious shock waves and expansion waves are seen, indicating that the charge scheme of partially cut Multiaperture stick propellant can improve launch safety.