Investigations of spontaneous condensation phenomena

• Main Author: Head, Richard M.
• Format: Others
• Published: 1949
• Online Access: https://thesis.library.caltech.edu/6346/1/Head_rm_1949.pdf; Head, Richard M. (1949) Investigations of spontaneous condensation phenomena. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/06R8-C778. https://resolver.caltech.edu/CaltechTHESIS:04212011-134533762 <https://resolver.caltech.edu/CaltechTHESIS:04212011-134533762>

The results of a systematic wind tunnel investigation into the attainment and ultimate collapse of the supersaturated state of water vapor are presented. These results, together with those of other recent investigations, are collected and compared with the theory. It is found that the deviations from the quasi-stationary conditions upon which the theory is based are very pronounced in the supersonic wind tunnel. A much higher degree of supersaturation can, therefore, be attained before condensation occurs than is predicted theoretically. Measurements at low temperatures indicate that if the water vapor reaches a temperature of about 153 °K, without the occurrence of condensation, the vapor will not condense upon further expansion, regardless of how highly supersaturated it becomes. This observation is in agreement with some recent Wilson Cloud Chamber investigations. The shock relations for flow-involving condensation are discussed. It is shown that two types of discontinuities can occur; the condensation shock and the shock with condensation (or vaporization). The latter solution has been disregarded in the past, but it is shown that the shock with vaporization is of importance and can result in appreciable errors in Mach number determination when droplets are present in the flow. Various techniques of measurement of the condensation processes in supersonic flow are considered.