Transient influence of water injection on the flow field of a hot launch in a W-shaped silo

This study attempts to determine the effect of and mechanisms for the suppression of the ignition pressure and back-flowing exhaust during a hot launch process in a W-shaped silo, considering the missile movement via dynamic mesh technology. The mixture model for the multiphase and the turbulent model employed were experimentally proved to be accurate and reliable. The numerical results show that the injection of water into a missile exhaust can effectively suppress the ignition overpressure, thereby reducing the time of oscillation and oscillation amplitude, and reducing the maximum pressure at missile bottom from 3.68 × 10⁵ Pa to 2.39 × 10⁵ Pa. In addition, water injection makes the back-flowing exhaust remain at the bottom of the launch duct instead of filling the duct, and it cools the missile bottom, thus leading to a reduction in the maximum temperature from 3000 K to approximately 500 K.