COBRA-TF (CTF) is a modernized and improved version of COBRA-TF (COlant Boiling in Rod Arrays-Two Fluid) that is used for performing subchannel thermal hydraulic analysis and modeling fuel rod thermo-mechanical behavior in light water reactors. CTF uses a three-field approach, whereby the vapor, continuous liquid, and droplets can be modeled independently in terms of field velocity. CTF has a coupling interface that has been used for coupling to other physics tools including neutronics, core chemistry, and fuel performance.
More information can be found at https://www.ornl.gov/division/rnsd/projects/ctf.