Validation of the STEG code using PGV experiments on hydrodynamics of horizontal steam generator

•The PGV test facility and the main experimental results are described.•Models of interfacial drag force are analyzed in detail.•The results of the validation of the STEG code are presented.•The predictions of void fractions are rather well, mainly in the range of 10%.•The predictions of pressure drops are mainly in the range of 30%. The results of the validation of the STEG code using the experiments on the PGV test facility are presented. The PGV test facility (Electrogorsk, Russia) is a slice of the upper part of the horizontal steam generator for Russian type VVER reactors. The main aim of the tests is to investigate the influence of submerged perforated sheets (SPSs) with uniform and non-uniform perforation degrees on the hydrodynamics of two-phase water-steam flows. The brief description of the STEG code based on the 3D two-fluid model is presented. The crucial constitutive laws that allow an accurate simulation of the PGV tests are the correlation for SPS pressure drop and the interfacial drag force model. The SPS pressure drop is calculated with empirical correlation obtained at the PGV experimental data. It is demonstrated that three different models of interfacial drag force are necessary in different regions of the test facility (above the SPS, below the SPS and zone between the tube bundle and the SPS). The formulations of the models are presented. All experiments are analyzed using the STEG code. The peculiarities of the spatial two-phase flows have been established, and a quantitative comparison with experimental data (SPS pressure drops and void fractions) has been performed. It can be argued that the results generally indicate the relatively good predictive ability of the STEG code.