Abstract Utilizing high-pressure and high-temperature gas as a power source for launching underwater vehicles presents significant challenges due to the unsteady flow characteristics of underwater gas jets. This paper presents a detailed examination of the complex interactions between two discontinuous gas jets emerging from the launch tubes, with a specific focus on how pulsating pressure affects the load characteristics of the launch platform (UUV). A three-dimensional numerical model is developed to investigate the dynamic characteristics of these discontinuous gas jets, and the model is validated against experimental data. The unsteady behaviors of the two discontinuous gas jets under various launch conditions (including simultaneous launch, inconsistent chamber pressure, and variable launch timing) are obtained through comparative analysis. Additionally, the impact of these unsteady behaviors on pulsating pressure and the load characteristics of the UUV is discussed in detail, emphasizing the correlation between interfacial instabilities and pulsating loads on the UUV. The pulsating load characteristics of different components of the UUV are associated with the unsteady behaviors of discontinuous gas jets, exhibiting distinct differences under various launch conditions.
Ye et al. (Wed,) studied this question.