Korean reunification question (1945- ) Korean reunification question (1945- ) / Fiction Abfluss Brennstoffzelle CFD Elektrochemische Energiequelle Elektrochemische Energieumwandlung Energiequelle Korea (North) PEM fuel cells Proton exchange membrane fuel cells Protonentransfer Thermoregulation Wasserkühlung Working class Working class / Korea (North) / Fiction analysis coupled thermal and water management energy fundamental heat transfer ice formation liquid water removal multiphase mixture (M2) formulation numerical simulation phase change polymer electrolyte membrane subfreezing operation thermal management two-phase flow