© 2019 Published under licence by IOP Publishing Ltd. In the future space exploration mission, transfer vehicle using cryogenic propellant and oxidizer will be likely operated. Thermal management systems, such as thermal insulation, pressure control, and reduction of boil off gas must be installed on transfer vehicle since cryogenic fluid has high volatile characteristics. Final target of this study is the development of thermodynamic vent system (TVS) utilizing jet mixing. Numerical simulation and ground based experiment for thermal and fluid behaviours in tank partially filled with liquid nitrogen were conducted. Thermal stratification in tank was formed by creating heat input from side wall, and change of temperature field and break of thermal stratification by jet mixing were investigated. Numerical results were evaluated by comparing with experimental results. © Published under licence by IOP Publishing Ltd.