An analysis was made of stable, laminar, free convection, film boiling from isothermal vertical plates and horizontal cylinders surrounded by a saturated liquid, where radiation was only of minor importance. The mathematical techniques of boundary layer theory were used and the boundary layer equations were reduced to ordinary differential equations by means of a transformation similar to those used in free convection and condensation. The equations were solved for: (1) compressible flow with variable specific heat, (2) variable specific heat and density variations considered only in the evaluation of the buoyant force, and (3) the case of constant properties. Numerical results were obtained for: (1) near critical water at 2800 and 3100 psia with wall to liquid temperature differences of 250, 500, and 1000 deg F; (2) for fluids with Prandtl numbers of 2/3, 1, and 2; and (3) for mercury and methanol film boiling at one atmosphere, considering constant properties. The results obtained by assuming constant properties were compared to: (1) the results obtained by considering variable properties, (2) experimental results, and (3) the comparable case of laminar film condensation. It was shown that the method of considering density variations only in the evaluation of the buoyant force is not valid in film boiling. It was also shown that the constant property solutions for heat transfer did not always agree with solutions obtained considering compressible flow and variable specific heat. An approximate analysis of a non-isothermal wall, including the effects of radiation, was presented. It was shown that for high emissivity walls at high temperature, radiation is the controlling factor in film boiling heat transfer.

The study of post-dryout heat transfer has generated great interest because of its importance in determining maximum clad temperature in nuclear reactor loss-of-coolant accidents (LOCAs). An associated phenomenon, the deterioration of heat transfer in boiling, is significant to other industrial sectors. This book provides comprehensive coverage of post-dryout heat transfer, discussing such essential topics as post-dryout heat transfer in dispersed flow, interpretation and use of transient data in surface rewetting by reinstatement of flow or by reducing heat flux, rod bundles, two-phase flow occurrences in the post-dryout region, various methods for predicting ""inverted annular flow,"" and new experiments for measuring thermodynamic nonequilibrium with probes in the channel. The book also presents a basis for independent safety assessment of nuclear reactors and chemical plant systems where post-dryout heat transfer may occur. Post-Dryout Heat Transfer will be a useful reference for researchers and professionals in the nuclear and chemical production industries.