Background. To date, studying of mixing processes of water coolant flows is an urgent problem of the nuclear power industry. Leading scientific groups are investigating these processes at the experimental facilities ROCOM (Germany), Vattenfall (USA), Fortum PTS (Finland), OKB GIDROPRESS (Russia). The interest in these studies is associated with the appearance of new calculation codes that allow modeling these processes but they need to be verified. That is why it is an urgent problem to study the mixing processes on a model (single loop) of the reactor installation, as well as to investigate the effect of external dynamic forces on these processes.
Materials and methods. A one-loop experimental model has been proposed for the study of mixing processes. The model is a simulation of one closed loop of a nuclear power plant. The main difference from the known models consists in the measurement method, which is based on direct temperature probing of the mixing region and the possibility to carry out the research in dynamic regimes, whose analogs are not available in open data sources.
Results. We have constructed temperature distribution curves along the mixing region for nonisothermal flows with a gradient of 10, 20, 30, 40 оC for static and dynamic regimes and determined the areas of location of turbulent vortices and stagnant zones. It has been found that for the dynamic regime, when periodic oscillations with the amplitude of 30о are applied to the model, the steady-state regime onset time increases. We have determined the correlation between the temperature pulsations and periodic oscillations.
Conclusions. The single-loop model for studying the processes of mixing of non-isothermal flows has allowed us to estimate the inhomogeneities and stagnant regions occurring when a flow of imitation passes through the output block both in the static and dynamic regimes. The large amount of experimental data that has been accumulated can be used to verify CFD programs, to find ways to intensify these processes in the problems of design and construction of modern ship reactor installations.