Numerical simulation of trailing edge vortex shedding

摘要

Vortex shedding is a self-excited unsteady flow phenomenon in turbomachinery blading with a blunt trailing edge. Since the formation of vortex streets produces a substantial component of the energy loss in gas turbines, understanding and predicting trailing edge vortex shedding is of great importance in turbomachinery for further improvement of mahcine performance. The paper presnets a numericla study on trailing edge vortex shedding using FV-TVD scheme. To assess the accuracy of the code, at first we calculate and analysis the unsteady flow field in a NASA turbine cascade and compare the average velocity distribution with the measurement of NASA Lewis Center. The results indicate that the computational results are in good agreement with the experimental ones. Since the vortex shedding in a turbomachinery blade row is affected by the incidence, we also perform a series of flow simulations to study the effect of incidence on trailing edge vortex shedding. The results indicate that, although the scale of the vortex shedding isn't affected by the incidence significantly, the incidence do have effect on the frequency of the trailing edge vortex and the loss generation of the blade row.