The current study presents a computational fluid dynamics (CFD) model for film boiling using two fluids, including liquid nitrogen. Ansys Fluent was customized using user-defined functions (UDFs) to accurately model thermal and fluid dynamic interactions. The UDFs accommodate mass transfer at the liquid-vapor interface, maintaining a sharp interface by accounting for the saturation temperature. Direct heat and mass transfer calculations are implemented rather than relying on empirical correlations. Mesh analysis was performed with grid sizes of 615, 410, 307, and 123 μm, with the 307 μm grid selected for its agreement with average Nusselt number values and accurate bubble shape and height. Verification using the Stefan problem showed a maximum error of 0.45 % for interface displacement and 0.1 % for temperature distribution. Validation against the Berenson correlation demonstrated good agreement in Nusselt number values. Qualitative validation of the developed method is performed using the shapes of the growing bubble. The results obtained show that the sharp interface is preserved throughout the simulation, with temperature contours showing significant variations during bubble growth and departure. Local heat transfer coefficient analysis identified peak values of 2170 W/m²-K at locations of minimal film thickness. Velocity vector analysis revealed velocities of 2 m/s in the vapor phase, influencing bubble shape during growth and departure. The study highlights the impact of thermal film thickness on heat transfer, with the highest Nusselt number of 5.69 observed at a film thickness of 0.5 mm. The results demonstrate the application of VOF sharp interface tracking and direct calculation of interfacial conditions utilizing customized Ansys Fluent in the modeling of film boiling as a way to understand the fundamental aspects of the fluid and thermal behavior.