Three-dimensional numerical investigations have been carried out to study subcooled flow boiling in a serpentine tube by using commercial software ANSYS Fluent 16.1 having built in volume of fluid (VOF) multiphase model. To model the vaporization process, user defined functions (UDF) have been used for computations of mass and energy transfer between the phases where user-developed subroutines are linked to the main hydrodynamic model equations. From the transient computations, bubble formation and departures during flow boiling at different tube sections have been captured and also the vapor volume fractions at bend section of the tube have been presented. An interesting observation at the adiabatic bend section is stratification of vapor and liquid. © 2018 Author(s).