TEMPERATURE PROFILES IN SUBCOOLED NUCLEATE BOILING

An experimental study of temperature profiles in the near vicinity of a horizontal copper surface on which water was boiled is reported in this thesis. A series of three tests is reported for heat fluxes of 20,000, 50,000 and 100,000 BTU/HRFT2 respectively. Four levels of subcooling were achieved in each series in the range of 0F < 0sub < 105F. Using the superheat-layer thickness as defined by Han and Griffith, results are reported indicating an increase in superheat-layer thickness for an increase in the degree of subcooling at a constant heat flux and a reverse effect for an increase in heat flux for a constant degree of subcooling. In addition, five tests are reported in which incipience of boiling was achieved. Using this data, Hsu's mathematical model for predicting bubble nucleation is tested. In general, good agreement is found between the Hsu model and the experimental data.