Study on Fuel Sloshing in Launch Vehicle Tanks and Response of Anti-Sloshing Plates

Violent shaking induced by motion excitation in a dynamic environment can generate significant additional forces and moments in liquid propellants, affecting spacecraft stability and attitude control. This study employs the CEL method to establish a fluid-structure interaction model for a launch vehicle fuel tank. The penalty function approach addresses FSI and hinged contact behavior, while the control volume method quantifies liquid pressure on anti-sloshing plates and propellant volume changes. Initial filling angles were used to simulate motion excitation equivalently. For partial filling conditions, the effects of equivalent filling height, initial filling angle, and anti-shake plate thickness on impact resistance were analyzed. Results indicate that at a fixed initial liquid filling angle, increasing the equivalent liquid filling height elevates both the maximum pressure and displacement of the anti-sloshing plate, though the rate of increase diminishes with greater plate thickness. At a fixed equivalent liquid filling height, increasing the initial liquid filling angle raises the maximum pressure, while the enlarged liquid-solid contact volume suppresses propellant sloshing, thereby reducing the displacement of the anti-sloshing plate. This study provides theoretical support for the structural design of anti-sloshing plates in rocket tanks.