A numerical investigation of two-phase steam flow around a 2-D turbine's rotor tip

摘要

In flow of steam during the divergence nozzles, expansion and decreasing the enthalpy, brings the flow near the saturation conditions. After supercooling, nucleation forms in the flow and the second phase appears. This phenomenon occurs specially during the last stages of steam turbines as low-pressure case and nuclear reactors as high-pressure. In this research, a numerical scheme for transonic two-phase flow within the passages of 2-D rotor-tip section with various backpressures is applied and an Eulerian-Eulerian reference frame is employed for both phases. A classical homogenous nucleation model applied for the mass transfer in the transonic conditions. Five deferent cases have been tested and through the results, pressure profiles around the blades are compared with the experimental data and good agreement is observed. Results show that the most condensation is on the suction surface of blade and it grows by decreasing the downstream pressure.