| Abstract: | ![]()
Patterns and characteristics of flow through heated tubes are investigated on the basis of concepts of two-phase dispersed annular flow patterns [1] within the framework of the three-velocity and single-temperature equilibrium model, with flowrates of the mixture not too close to critical. Conditions for onset of burnout of the second kind, i.e., deterioration in the transfer of heat leading to an abrupt rise in the temperature of the heating surface, and, as such, associated with desiccation of the thin film of liquid on the wall [2, 3], are investigated. Hydraulic drag, the flowrate of liquid in the film, and the true steam content by volume are among the factors discussed. Two-phase flow patterns in dispersed annular flow are characterized by the combined motion of the three components of the mixture: vapor, the liquid wall film, and droplets. The assumption entertained is that each component of the mixture acquires its own velocity, and that the temperature of the mixture is equal, in each cross section through the channel, to the saturation temperature at the pressure prevailing in the particular cross section.Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 4, pp. 78–88, July–August, 1973. |
