Numerical Comparison of Thermal Stratification due Natural Convection in Densified LOx and LN2 Tanks

The growth of natural circulation and thermal stratification inside LOX, LN2 storage tanks due to heat transfer from surroundings is investigated using a non-equilibrium, two-domain, mathematical model. The two-dimensional model is considered for the liquid domain in two cases and a lumped, thermodynamic model is utilized for vapor domain. The vapor is assumed to behave like an ideal gas. The developed mathematical model for liquid domain consists of conservation of mass, momentum, energy equations with Boussinesq approximation. The coupling of two domains is carried out using energy balance at the interface. An implicit, finite-volume technique with a uniform mesh for liquid domain is used to predict the velocity and temperature fields.