Experimental Study on Gas–Liquid–Solid Interaction Characteristics in the Launch Tube

Abstract

In the present study, a visual experimental system was built to explore the multiphase hydrodynamic features in the underwater launching process. The whole processes of gas-curtain generation produced by multichannel jet convergence, gas-curtain expansion, and projectile movement were captured using direct photography. The experimental results show that as the area of a single groove grows from 6.25 mm2 to 11.25 mm2, the gas-curtain displacement grows by 47.5%, and the projectile’s speed reduces by 34.1%. The expansion of the gas curtain can be aided by 36.0% by increasing the number of sidewall grooves within a specified range (4 to 8), but the vehicle’s speed is reduced by 53.8%. While increasing the maximum injection pressure from 9.9 MPa to 18.2 MPa, the gas curtain’s draining capability is improved by 29.6%, and the projectile speed increment diminishes (only 10.0%) as the amount of gas flowing into the front of the projectile grows. The impact of jet parameters on gas-curtain displacement and projectile speed is revealed in this study, which is of utmost significance to the parameter-matching design of underwater low-resistance launchers.

Keywords

• drag reduction
• drainage
• gas curtain
• gas jet
• underwater launch