Classical Helium Heat Transfer

To obtain a better physical feeling for pool boiling heat transfer, it is helpful to consider a hypothetical experimental system. Such an experiment, shown in Fig. 5.1, consists of a flat heated plate with some arbitrary orientation exposed to an effectively infinite bath of liquid helium. The experiment consists of heating the plate from inside the insulated region and measuring the temperature difference between the bath and surface, ΔT s , as it varies with heat flux q. There are a number of variables that affect the results in this experiment. Among these are bath temperature and pressure, surface orientation, physical characteristics of the heated surface including coatings, and frequency of heat flux. The general impact of these variables is described further below.