Numerical investigation of the performance of moisture separators based on two-way coupling model by Lagrangian-Eulerian methodology

Abstract Moisture separator is one of the crucial equipment of the pressurized water reactor (PWR) nuclear power plant. In the separators, droplets could be regarded as the dispersed phase in terms of the gas–liquid two-phase flow. In order to predict the pressure drop of the droplet-laden flows in a more reasonable way, a fully two-way momentum coupling model based on the Lagrangian-Eulerian methodology is established. Then, a skilled self-programming code is implemented into the commercial CFD software FLUENT by the interface called User Defined Function (UDF) to solve this two-way coupling model. In the model application part, we first perform the numerical investigation of three different kinds of wave-type separators. The magnitude of the modeling separation efficiency and the changing trend of the pressure drop are in good agreement with the experimental data. Second, the gas–liquid flow in a swirl-vane separator is simulated under different operation conditions. The maximum relative error of the pressure drop by the two-way coupling model is over two times less than the simulation results by the one-way coupling model. Hence, the results show that the two-way coupling model, as well as the UDF solving program, performs a more comprehensive approach for the modeling of the gas–liquid two-phase flows in the moisture separators.