The increasingly widespread use of liquid hydrogen (LH2), particularly for low-carbon mobility, raises safety issues given its highly flammable nature. One of the major accidents involving cryogenic systems is the air ingress following a rupture of the outer shell of a vacuum-insulated tank. In such an event, the gases in the air liquefy and solidify on the cold walls, resulting in a high heat deposit and sudden system overpressure. The discharge line and the safety devices must be sized to evacuate the cryogenic fluid safely and avoid any risk of explosion. The aim of this thesis is to develop a model to simulate this type of scenario using the CATHARE code. A particular effort will be made to model heat exchange by liquefaction and solidification through the tank wall. This work will benefit from the loss of vacuum experimental campaign to be carried out in LH2 by CEA as part of the ESKHYMO ANR project. In addition, the use of a CFD local-scale simulation tool such as neptune_cfd could help in the construction of models in CATHARE by up-scaling. Finally, the methodology developed will be applied to simulate a system representative of an industrial facility.