The Effect of Wave Breaking on the Sloshing Induced Pressure Drop in a Horizontal Circular Tank

Ensuring a consistent fuel supply in next generation liquid hydrogen propelled civilian aircraft presents a research challenge, due to sloshing induced pressure drops in the ullage space. Civilian aircraft must operate across a wide range of flight profiles, making reliable fuel delivery crucial for safe and efficient propulsion. While past research has explored pressure drops in cryogenic fuel tanks, studies examining pressure drops in horizontal circular tanks are scarce. To address this gap, a novel non-isothermal experimental setup has been developed to analyse wave kinematics, ullage pressure, and fluid temperature responses under various sloshing regimes. Sloshing wave conditions are excited at different accelerations to assess the dependence of pressure drops on wave breaking. This experimental investigation examines the sensitivity of wave breaking to interfacial condensation showing that the largest pressure decay occurs where wave breaking is present. Complete thermal destratification is displayed where wave breaking is present, whilst low acceleration cases which do not initiate significant wave breaking see small pressure drops which reduce the thermal gradient between phases but retain some degree of temperature stratification.