Experimental study of inward freezing in circular and square pipes

This paper describes the results of an experimental study of the inward freezing of water in tubes of circular and square geometries. The temperature-time history is recorded using thermocouples, from which the progress of the freezing front is deduced. The results obtained pertain to the conditions of water not initially at freezing temperature, the outside surface temperature of the tube varying with time. Since the available theories assume liquid to be initially at freezing temperature and a constant sub-freezing temperature at the outside surface, a rigorous comparison is not possible. In order to make some sort of comparison, the sensible heat of water has been incorporated into the latent heat while the actual surface temperature variation has been replaced by its time-average value. Despite these approximations, the experimental results are in reasonable agreement with the theory.