Microgravity two-phase flow research in the context of vapor compression cycle experiments on parabolic flights

•Microgravity two-phase flow fundamentals directly compared with system level research from parabolic flights.•Condensation heat transfer was found to be reduced due to microgravity by fundamental studies and system level testing.•Effects of microgravity on friction and evaporation heat transfer coefficient very small for system level testing.•Decreased gravity dependence for higher flow velocities partially confirmed on system level through inclination testing.•Fundamental and system level research for microgravity two-phase flow should be closer aligned to increase mutual utility.