SUMIARYPrediction of dermal injury resulting from exposure to thermal energy of any given intensity and duration depends entirely upon the resultant skin temperature-time history. Means are now available for assessing heat transfer by low temperature radiation, convection and conduction to the bare skin and through thin protective coverings of known physical properties.However, thermal effects of nuclear detonations constitute a special problem because much of the radiation lies in the visible range where the optical properties of the skin and its coverings, if any, greatly influence the heating pattern. Blackening of the skin eliminates e:fects due to its optical properties but enhances the ever-present variations in the thermal "constants" of the skin. The present report describes the utilization of a mathematical equation and computer techniques for extracting these variations from empirical data obtained at relatively low levels of radiation (<0.5 Cal /cm 2 sec ), and applying extrapolations of these values in calculations of temperature-time histories at higher levels of irradiance where empirical data are lacking. This procedure is subject to validation by experimentation within a limited range of exposures.If validation is achieved in the blackened skin then the entire system may be utilized in the determination of optical properties of unblackened skin.Sii

SUMIARYPrediction of dermal injury resulting from exposure to thermal energy of any given intensity and duration depends entirely upon the resultant skin temperature-time history. Means are now available for assessing heat transfer by low temperature radiation, convection and conduction to the bare skin and through thin protective coverings of known physical properties.However, thermal effects of nuclear detonations constitute a special problem because much of the radiation lies in the visible range where the optical properties of the skin and its coverings, if any, greatly influence the heating pattern. Blackening of the skin eliminates e:fects due to its optical properties but enhances the ever-present variations in the thermal "constants" of the skin. The present report describes the utilization of a mathematical equation and computer techniques for extracting these variations from empirical data obtained at relatively low levels of radiation (<0.5 Cal /cm 2 sec ), and applying extrapolations of these values in calculations of temperature-time histories at higher levels of irradiance where empirical data are lacking. This procedure is subject to validation by experimentation within a limited range of exposures.If validation is achieved in the blackened skin then the entire system may be utilized in the determination of optical properties of unblackened skin.Sii

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The influence of augmenting and opposing thermal and solutal buoyancy forces on natural convection of binary gases due to horizontal temperature and concentration gradients is examined through comparison of smoke flow visualization and measured temperature and concentration distributions with numerical predictions. The observed flow at the cold wall was unsteady for opposing body forces. The same basic flow structure was observed, but the unsteady flow intensifies as the opposing solutal buoyancy force increases as compared to the thermal buoyancy force. Comparison of predicted and measured temperatures and concentrations is fair overall, but the steady-state analytical model fails to predict the unsteady flow and heat and mass transport for opposing body forces.

The paper reports on an experimental and analytical study of freezing of a liquid-saturated porous medium. Experiments have been performed in a cylindrical capsule cooled from the outside and oriented vertically and horizontally to obtain quantitative temperature distribution and fusion front motion and shape data. Different-size glass and aluminum spherical beads were used for the porous medium, and distilled water was used as the phase-change material. A mathematical model, based on a one-dimensional analysis which considered heat conduction as the only mode of heat transfer in both the solid and liquid regions, has been developed and sensitivity studies have been carried out. Comparison of experimental data with predictions of the solid–liquid interface position and temperature distribution shows good agreement and thus confirms the mathematical model for a system of glass beads and water. However, for a system of aluminum beads and water the thermophysical property model is inadequate, and agreement between predictions and data is relatively poor.