EXPERIMENTAL AND CALC_D TEMPERATURE AND MASS HISTORIES (F VAPORIZING FUEL DROPS

The present report compares experimental and calculated mass and temperature histories of drops vaporizing with a constant velocity rela-tive to the air and confirms the thought that, under many conditions, the unsteady state or time required for the drop to reach the wet-bulb tempera-ture is an appreciable portion of the total vaporization time. Work was done to verify or disprove the assumptions used in the com-putations. Data are presented to show that the assumption of infinite thermal conductivity is valid primarily because of circulation inside the drop. The presence of this circulation was verified by hlgh-speed motion pictures. The need for a correction factor to the heat transfer to express the effect of mass transfer on heat transfer was confirmed as well as the need for a correction factor to correct for unidirectional (as opposed to equimolal) diffusion. Work was also done to evaluate the extent and effect of heat trans-fer down the thermocouple wires supporting the drop. It was shown tha