This paper summarizes theoretical studies and some laboratory experiments on dodecane, a retrograde substance. A singular feature of the thermodynamic behavior of this class of substances may be used with advantage in systems where liquid-vapor phase transition is present. ?ordingly, a substance with a sufficient degree of retrogradicity can, in theory, undergo a complete phase change in a nearly isentropic rapid depressurization process, which is an impossibility for regular substances, such as water and ethanol. Laboratory experiments with dodecane at increasing temperatures confirmed the trend of obtaining complete evaporation. Estimations showed that at the highest test temperature, 300°C, a vapor quality above 90% was obtained in comparison with a vapor quality of 25% at the test temperature of 180°. In these experiments, a small volume of test liquid was suddenly exposed to a low-pressure chamber by rupturing a diaphragm and the phase transition proceeded via a wave or front of evaporation. A still picture of an evaporation wave is presented. An analysis of the necessary conditions for obtaining a complete evaporation wave problem is also included. Experimental data along with the results of analyses of the problem are presented. At the end the paper presents a brief discussion of the application of this phenomenon to fuel injectors.
