Correlation of time dependent recovery from film boiling heat transfer in He II

A correlation is presented that describes the behaviour of time dependent recovery from film boiling in He II. In a one dimensional heat transfer experiment, the recovery time from the film boiling once heat generation stops is observed to be a function of the energy applied to the heater during film boiling. This correlation has a power law dependence which can be physically understood in terms of heat capacity of the heat transfer sample and the film boiling heat transfer coefficient. A direct comparison of experimental data with the analysis is achieved by adjusting the value of the transient film boiling heat transfer coefficient. Data can be predicted to within 20% for recovery under SVP conditions. The results are somewhat less certain for data taken in subcooled He II. (author)