The one-dimensional separate two-phase flow model of APROS

The publication describes the one-dimensional two-fluid model of the computer program APROS used for the simulation of nuclear and conventional power plants. The work is based on the technical report from 1992. The treatment of the non-condensable gas mass equation has been added. The test results have been updated, so that the results correspond to the present APROS version 5.08. The derivation of the model from the governing partial differential equations is shown in detail and the solution procedure is described. Correlations for interfacial and wall friction and for heat transfer have been used to close the set of the linear equations. The friction and heat transfer packages of the model are documented. Finally, results of test cases calculated with the present model are briefly discussed