The scientific goal is the experimental investigation and modeling of the CHF and Post-CHF heat transfer at high pressure. The experiments will be conducted on a total of three facilities, each with a different fluid. Once with Freon R134a at the KIMOF of the IATF/KIT, with Water at the HIPER of the LES/TUM and once with CO2 at the Scarlett of the IKE/University of Stuttgart. The modelling part will be done in cooperation with all project partners and will be implemented into the STH-Program with the help of GRS gGmbH, which will increase the meaningfulness.