Liquid-propellant rocket engines are the most widely used space propulsion system for delivering payloads into orbit. The high specific impulse achieved with cryogenic propellants makes them the preferred fuel for rocket engines. However, one of the biggest challenges of using cryogenic fluids is to estimate the process of cooling down the system to the temperature of the cryogenic fluid before ignition, i.e. the chill-down. In a rocket engine, the cryogenic propellants are supplied until the Main Feed Valve (MFV) before ignition. With the cryogen at much lower temperature than the valve structure, a complex heat transfer process takes place until the valve completely cools down. The lack of accurate models to predict this cryogenic heat transfer process obliges to conduct long components tests and to use engineering estimations with excessive margins of safety. This results in expensive tests and long development times. Additionally, this implies excessive use of propellants or substitute cryogenics during flight preparation, which increases launch costs. Accordingly, the University of Luxembourg and ArianeGroup aim to investigate, experimentally and numerically, the heat transfer process between the cryogen and the valve in order to both obtain high-end CFD data and to develop more reliable and more accurate heat transfer models to estimate the MFV chill-down process. The final objective is to integrate the obtained heat transfer models into ArianeGroup’s engineering workflow to optimize the current design of cryogenic valves and thus reduce tests costs and development times.