Forced convection heat transfer of liquid hydrogen through a 200-mm long heated tube

The heat transfer from the inner side of a vertically-mounted heated tube with a length of 200.0 mm and a diameter of 6.0 mm to a forced flow of liquid hydrogen was measured for wide ranges of flow rate and liquid temperature. The non-boiling heat transfer coefficients agreed well with the Dittus -Boelter equation. The heat fluxes at departure from nucleate boiling (DNB) were higher for higher flow velocities and greater subcooling. The effect of the tube length on the DNB heat flux was clarified through comparison with our previous data. It was confirmed that the experimental data agreed well with the authors' DNB correlation. (C) 2012 Published by Elsevier B. V. Selection and/or peer-review under responsibility of the Guest Editors.