Numerical simulation of flow field in a Compact Quad-Missile Vertical Hot-Launch System

This study presents a detailed computational investigation of the internal flow field within a Compact Quad-Missile Vertical Hot-Launch System (Compact Quad-Missile VSL), a novel shipboard launcher designed to improve spatial efficiency and firepower density. A full-scale 3D unsteady compressible flow model is developed using the Navier-Stokes equations and the Realizable k-ϵ turbulence model, with dynamic mesh technology applied to simulate missile motion. Grid independence and model validation are conducted against benchmark experimental data to ensure reliability. Four missiles are sequentially launched from four symmetrically arranged tubes with a 0.5 s interval. Flow field evolution, including pressure and temperature distributions, is analyzed across different launch orders. Results show that the first missile experiences the most severe gas choking and thermal effects, while subsequent missiles benefit from improved venting efficiency due to prior launches. Notable gas-injection and wall-attachment effects are observed, influencing the local thermal environment and missile surface heating. Kinematic analysis further reveals that the peak acceleration and exit velocity decrease progressively from Missile 1 to Missile 4, correlating with changes in base pressure and gas dynamics. This work provides insight into the multiphysics coupling of flow field evolution and missile motion during vertical hot launches and offers valuable guidance for the structural and thermal design of compact high-density VLS systems.