Common bulkhead tank and zero boil-off technology are ideal solutions for liquid oxygen and liquid methane propellant pair storage in reusable launch vehicles. An experimental setup was established to investigate the thermodynamic behavior in a synthermal common bulkhead tank. The influences of the common bulkhead storage temperature, warm wall boundary temperature and filling ratio on the storage state are analyzed. Experimental results show that the thermal stratification decreases with the increase of the common bulkhead storage temperature, and the total storage duration of liquid oxygen increases with the rise of its filling ratio. At the storage temperature of 105.8 K, a cooling power of 3.17 W is required to achieve zero boil-off storage for the present configuration. The minimum temperature gradient inside the tank is 6.1 K/m, and the minimum temperature difference between the two compartments is 0.2 K, which is recognized as the most stable and economical storage. In addition, maintaining a high liquid oxygen level is conducive to prolonging the total self- pressurization and venting duration. The study confirms the feasibility of the synthermal common bulkhead storage scheme, which may simplify the manufacture of the common-bulkhead fuel tanks and improve the reliability of the reusable cryogenic spacecrafts.
