Abstract

The gaseous jet of the solid rocket motor running under water is influenced by both gravity and buoyancy, which will have a significant influence on the flow field structure and thrust of the motor, especially in the initial period when vehicles are launching horizontally. The work in this paper consists of three parts: firstly, to understand the mechanism of the thrust oscillation characteristics and the jet structure of a solid rocket motor running under water, as affected by gravity and buoyancy, a 3-d numerical simulation using the volume of fluid (VOF) model was established. Compared with those results neglecting gravity and buoyancy, conclusions were obtained that the jet structure, considering gravity and buoyancy, are more consistent with the experimental results. Secondly, the principle of momentum was used to analyze the flow field structure and the thrust oscillating characteristics in the initial period of operation. Finally, after analyzing the density gradient along the axis of the motor, results indicated that the length of jets under the influence of gravity and buoyancy varies linearly and the slope of the line is related to the working conditions. Comparing the trajectories under different conditions, a common theme emerged. The laws of thermodynamics are also used to simulate the jets as gas-water-vapor, three-phase, systems. The effect of phase transitions on the structure of jets and the characteristics of their thrust form the key conclusions.

Highlights

  • Solid rocket motors used in the propulsion systems of high-speed vehicles travelling in deep water require mobility and flexibility, which is conducive to long-term operations [1]

  • This paper studies the motor injected horizontally underwater with the influence of gravity and buoyancy

  • The basic jet structure considers the influence of gravity and buoyancy

Read more

Summary

Introduction

Solid rocket motors used in the propulsion systems of high-speed vehicles travelling in deep water require mobility and flexibility, which is conducive to long-term operations [1]. Zhu [5, 6] et al adopted the VOF model to get numerical results from a simulation of isothermal high-speed hot gaseous jets, and it was revealed that the changes in some flow parameters, such as the pressure and Mach number in the bubble, were important. A few studies adopted three-dimensional models, such research is merely a qualitative validation without considering the specificity of the model It cannot precisely describe the appearance of the bubble with gravity and buoyancy effects in an underwater gaseous jet. The flow structures, thrust oscillation characteristics, the length of the jets, and their trajectories are presented These results offer guiding significance to engineering practice

Fundamental equations
Governing equations
Gravity equation
Basic flow structure
Typical processes
Initial perturbation analysis
Characteristics of underwater thrust oscillation
The effect of working conditions on initial jet range
2.78 Simulation data
The effect of working conditions on jet buoyancy
Underwater jets and their phase transitions
Conclusions
Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.