Turbulence Model Comparative Study for Complex Phenomena in Supersonic Steam Ejectors with Double Choking Mode

Scholars usually ignore the non-equilibrium condensing effects in turbulence-model comparative studies on supersonic steam ejectors. In this study, a non-equilibrium condensation model considering real physical properties was coupled respectively with seven turbulence models. They are the k-epsilon Standard, k-epsilon RNG, k-epsilon Realizable, k-omega Standard, k-omega SST, Transition SST, and Linear Reynolds Stress Model. Simulation results were compared with the experiment results globally and locally. The complex flow phenomena in the steam ejector captured by different models, including shock waves, choking, non-equilibrium condensation, boundary layer separation, and vortices were discussed. The reasons for the differences in simulation results were explained and compared. The relationship between ejector performance and local flow phenomena was illustrated. The novelty lies in the conclusions that consider the non-equilibrium condensing effects. Results show that the number and type of shock waves predicted by different turbulence models are different. Non-equilibrium condensation and boundary layer separation regions obtained by various turbulence models are different. Comparing the ejector performance and the complex flow phenomena with the experimental results, the k-omega SST model is proposed to simulate supersonic steam ejectors.

Automated summary

In this study, a non-equilibrium condensation model considering real physical properties was coupled with seven turbulence models to investigate the complex flow phenomena and the impact on the performance of supersonic steam ejectors. The results showed differences in the predictions of shock waves, non-equilibrium condensation, and boundary layer separation by different models.