Numerical investigation of N2O4-NO system condensation on the horizontal tube

The addition of small amounts of NO (1-3%) into N2O4 coolant above stoichiometric composion is the effective method of the corrosion rate decrease of structural materials in dissociating nitrogen tetroxide in the range of phase transitions. Heat and mass transfer is modelled numerically during laminar condensation of N2O4 - NO system in anlimited volume on horizontal tube in two-dimensional approximation. In gas phase pentacomponent mixture of N2O4, NO2, N2O3, NO and O2 is considered, wherein N2O3, NO and O2 components are noncondensable under common conditions. Liquid phase is considered to be common substance with effective thermal properties. Mathematical modelling of the condensation process of the considered system is accomplished in the approximation of the boundary layer theory. It is proved, that introduction of nonstoichiometric NO additions doesn't affect noticeably the mechanism of tramsfer processes during N2O4 condensation, and some reduction in the intensity of heat transfer in this case reguires compensation in the heat transfer surface within the limits of generally taken stores