EXPERIMENTAL AND NUMERICAL STUDY OF UNSTEADY AERODYNAMICS IN AN OSCILLATING LOW-PRESSURE TURBINE CASCADE OF ANNULAR SECTOR SHAPE

摘要

The unsteady aerodynamics during controlled blade oscillation in an annular sector cascade with low-pressure turbine (LPT) blades has been studied experimentally and numerically. Following the influence coefficient approach, a cascade of seven blades has been employed with the middle blade made oscillating in controlled modes. One of the novelties of the presented study is the combination of three-dimensional (3D) flow and 3D blade oscillation due to increasing bending amplitude from hub to tip as present for low-order structural modes. On the numerical side, a linear Euler flutter prediction tool has been used at different degree of detailing. The results indicate that the inviscid model is capable of capturing the main features of the unsteady aerodynamics during blade oscillation and that it can be used to support design work.