Investigation of mixed convection caused in superconducting generators

In this paper, the influence of a macro-flow, which is some kind of natural convection caused by heat-in leak in rotational cryostats, has been investigated. A macro cooling channel unit which generates a main flow counter to the buoyancy direction has been made to simulate the macro-flow influence. A high-speed camera has been used to observe the transient local convection. Also a thin film thermometer has been used to detect the transient temperature variation. As the result, some fluctuation caused by the macro-flow has been observed in the transient convection. The degradations of the transient temperature variation and the maximum heat flux have been measured.