Interface reorientation of cryogenic liquids under non-isothermal boundary conditions

•We performed experiments on the interface reorientation from 1 g to almost 0 g.•Wall temperature gradients (0.2–2.9 K/mm) as well as LAr and LCH4 were used.•The reorientation depends on the gradient value and the liquid properties.•The wall superheat influence is shown through the deflection of the contact line.•A simulation shows a qualitative agreement with previous experimental results.

We investigate the capillary driven oscillations of the liquid–vapor interface in cryogenic systems under non-isothermal boundary conditions. The oscillations took place in a partly filled cylinder during the interface reorientation from its 1 g equilibrium position to the microgravity equilibrium position after a step reduction of gravity. The latter was achieved by dropping the experimental device in the drop tower of Bremen, providing 4.7 s of microgravity. Liquid argon (Tsat=87.3K at 1013 hPa) and liquid methane (Tsat=111.7K at 1013 hPa) were used as experimental liquids. Axial wall temperature gradients, corresponding to a linear increase of the wall temperature, were applied above the interface position prior to the experiments with values varying between 0.2 K/mm and 2.9 K/mm. Both liquids showed a qualitatively similar reorientation behavior. The reorientation characteristics were found to depend on the value of the applied gradient and on the material properties of the experimental liquids. Numerical simulation showed a good qualitative agreement with a previous experiment with 1.34 K/mm using liquid argon, demonstrating main characteristic features of the experiment.