CFD modeling of subcooled flow boiling for nuclear engineering applications

In this work a general-purpose CFD code CFX-5 was used for simulations of subcooled flow boiling. Some important modelling issues were investigated: heat flux partitioning, turbulence modelling and non-drag forces. The subcooled boiling model, available in a custom version of CFX-5, has been used here. The special treatment of the wall boiling boundary, based on analytical temperature wall function, assures the grid invariant solution. The calculations been validated against the published experimental data of high-pressure flow boiling in a vertical pipe covering a wide range of conditions (relevant also to the pressurized water reactor).