Cryogenic propellants that have been sub-cooled are placed into cryogenic tanks utilized for space applications. A heated layer of liquid forms close to the liquid-vapor interface during the protracted periods of time before launch when heat from outside sources escapes into the tank. Thermal stratification is the term for this process. A transient, two-phase, thermodynamic model of thermal stratification in a cryogenic tank was constructed in this work. The model considers the flow of the propellant boundary layer caused by nearby natural convection. MATLAB was used to solve equations relating to continuity, momentum, energy, and mass transfer. Studies were then conducted to ascertain the impact of stratified mass liquid temperature and liquid Pressure profile on liquid sub-cooling in the propellant tank. According to the study, sub-cooling the cryogenic tank results in a higher stratified mass. The findings of this study can be applied to enhance cryogenic tanks operation and design for space applications. Specific Objective- • To establish the variation of temperature and pressure with the heat radiant on the outside wall of the tank. • To identify any factors affecting the relationship between temperature, pressure, and radiant heat.