Experiments on transient pool boiling heat transfer to liquid helium 4 for the step type heat flux,q,application have been carried out at the atmospheric pressure. Thin carbon films worked as heater and as thermometer at the same time. Two types of test piece were made. Substrate of the first type had carbon film on one side of it and that of the second type was sandwiched between two layers of carbon film to reduce the heat loss. The temperature excursions were measured in the heat flux range from 1. 9 to 100 left bracket kW/m**2 right bracket . The results have indicated that the Kapitza conductance h k,ref at the reference temperature Tk,ref ( equals 4. 2 left bracket K right bracket in this report) is around 30 left bracket kW/m**2 multiplied by (times) K right bracket and the time at the onset of transition to film boiling tf obeys a q** minus **2 relationship.
|Title of host publication||Proceedings of the International Cryogenic Engineering Conference|
|Editors||Gustav Klipping, Ingrid Klipping|
|Number of pages||6|
|Publication status||Published - 1986|
All Science Journal Classification (ASJC) codes